Deze flashcards zijn nog niet opgeslagen — ze verdwijnen zodra je weggaat. Maak een gratis account aan om ze te bewaren en krijg toegang tot alles hieronder.
What is sexual dimorphism as defined in the text?
Differences in gene sequences on the sex chromosomes only
Any differences between individuals of the same sex due to environment
Sex differences in morphology, physiology, and behavior arising from sexual differentiation mechanisms
Behavioral differences unrelated to reproductive function
What is sexual dimorphism as defined in the text?
Differences in gene sequences on the sex chromosomes only
Any differences between individuals of the same sex due to environment
Sex differences in morphology, physiology, and behavior arising from sexual differentiation mechanisms
Behavioral differences unrelated to reproductive function
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In mammals with XX/XY systems, which genotype corresponds to genetic females?
XX
ZW
ZZ
XY
In mammals with XX/XY systems, which genotype corresponds to genetic females?
XX
ZW
ZZ
XY
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What role does SRY play in mammalian gonadal sex determination?
SRY on the Y chromosome drives testis development (testis-determining factor)
SRY controls dosage of DMRT1 to determine gonads
SRY determines phenotypic sex by producing Müllerian inhibiting substance directly
SRY causes ovary development on the X chromosome
What role does SRY play in mammalian gonadal sex determination?
SRY on the Y chromosome drives testis development (testis-determining factor)
SRY controls dosage of DMRT1 to determine gonads
SRY determines phenotypic sex by producing Müllerian inhibiting substance directly
SRY causes ovary development on the X chromosome
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In birds (ZZ/ZW), which gene and mechanism is described for gonadal sex determination?
SRY on the W chromosome determines testes
Dosage-dependent DMRT1 expression (higher in ZZ) promotes testes; lower expression promotes ovaries
Estrogen dosage on W determines male gonads
Dosage of AMH on Z controls ovarian development
In birds (ZZ/ZW), which gene and mechanism is described for gonadal sex determination?
SRY on the W chromosome determines testes
Dosage-dependent DMRT1 expression (higher in ZZ) promotes testes; lower expression promotes ovaries
Estrogen dosage on W determines male gonads
Dosage of AMH on Z controls ovarian development
Bekijk hier je kaarten, of sign up to study with spaced repetition.
According to the text, what hormonal combination leads to male internal genitalia in mammals?
Testes secrete estrogen which promotes Wolffian ducts
High DMRT1 and estrogen together cause male internal genitalia
Testes produce androgens plus MIS (Müllerian inhibiting substance), maintaining Wolffian ducts and causing Müllerian regression
Absence of androgens and presence of estrogen, maintaining Wolffian ducts
According to the text, what hormonal combination leads to male internal genitalia in mammals?
Testes secrete estrogen which promotes Wolffian ducts
High DMRT1 and estrogen together cause male internal genitalia
Testes produce androgens plus MIS (Müllerian inhibiting substance), maintaining Wolffian ducts and causing Müllerian regression
Absence of androgens and presence of estrogen, maintaining Wolffian ducts
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which of the following is NOT one of the three fish sex-determination mechanisms listed?
Chromosomal systems (XX/XY or ZZ/ZW)
Flexible, hormone-dependent sex with exogenous hormone effects
Social dominance-based sex determination only
Polygenic or no clear sex chromosomes
Which of the following is NOT one of the three fish sex-determination mechanisms listed?
Chromosomal systems (XX/XY or ZZ/ZW)
Flexible, hormone-dependent sex with exogenous hormone effects
Social dominance-based sex determination only
Polygenic or no clear sex chromosomes
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which environmental agents are named as endocrine disruptors that can modify sex determination?
Only heavy metals like lead and mercury
Viral infections during incubation
Environmental estrogen mimics (ethinyl estradiol, BPA, nonylphenol, some pesticides) and anti-androgens (fungicides, phthalates, herbicides)
Natural variation in temperature with no chemical influence
Which environmental agents are named as endocrine disruptors that can modify sex determination?
Only heavy metals like lead and mercury
Viral infections during incubation
Environmental estrogen mimics (ethinyl estradiol, BPA, nonylphenol, some pesticides) and anti-androgens (fungicides, phthalates, herbicides)
Natural variation in temperature with no chemical influence
Bekijk hier je kaarten, of sign up to study with spaced repetition.
For temperature-dependent sex determination in reptiles and amphibians, when is the critical window for temperature influence?
Only during adult sexual maturation
Immediately before hatching only
Roughly the middle third of incubation after oviposition
The first day after oviposition only
For temperature-dependent sex determination in reptiles and amphibians, when is the critical window for temperature influence?
Only during adult sexual maturation
Immediately before hatching only
Roughly the middle third of incubation after oviposition
The first day after oviposition only
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which taxa are given as examples where sex ratios vary with temperature during the middle-third period?
Lizards, alligators, most turtles, snapping turtles, and snakes
Mammals such as mice, rabbits, and primates
Most birds like chickens and pigeons
Amphibians such as frogs and salamanders only
Which taxa are given as examples where sex ratios vary with temperature during the middle-third period?
Lizards, alligators, most turtles, snapping turtles, and snakes
Mammals such as mice, rabbits, and primates
Most birds like chickens and pigeons
Amphibians such as frogs and salamanders only
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What defines a protandrous sex change pattern in animals?
Individuals are genetically fixed as one sex and never change
Individuals mature first as females and later change to males; change driven by temperature
Individuals change sex multiple times daily based on light cycles
Individuals mature first as males and can later change to females; change driven by social/behavioral cues such as loss of a female
What defines a protandrous sex change pattern in animals?
Individuals are genetically fixed as one sex and never change
Individuals mature first as females and later change to males; change driven by temperature
Individuals change sex multiple times daily based on light cycles
Individuals mature first as males and can later change to females; change driven by social/behavioral cues such as loss of a female
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What triggers protogynous sex change according to the notes?
Exposure to excess androgens during embryogenesis
Seasonal day length changes only
Loss of the dominant male or shifts in social hierarchy
A prolonged drop in environmental temperature
What triggers protogynous sex change according to the notes?
Exposure to excess androgens during embryogenesis
Seasonal day length changes only
Loss of the dominant male or shifts in social hierarchy
A prolonged drop in environmental temperature
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What are the two principal functions of testes listed in the notes?
Gametogenic function producing motile sperm; endocrine function secreting inhibin, MIS, prostaglandins, androgens, and estrogens
Gametogenic function producing ova; endocrine function secreting progesterone and IGF1
Producing egg yolk and storing fertilized eggs
Only endocrine function with no gametogenesis; secreting thyroid hormones
What are the two principal functions of testes listed in the notes?
Gametogenic function producing motile sperm; endocrine function secreting inhibin, MIS, prostaglandins, androgens, and estrogens
Gametogenic function producing ova; endocrine function secreting progesterone and IGF1
Producing egg yolk and storing fertilized eggs
Only endocrine function with no gametogenesis; secreting thyroid hormones
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What are the two principal functions of ovaries listed in the notes?
Gametogenic function producing ova; endocrine function secreting estrogens, androgens, progesterone, inhibin, oocyte maturation factors, and IGF1
Only gametogenic function producing sperm; no endocrine secretion
Storing and releasing urine into the cloaca
Endocrine function producing only corticosteroids; no gametogenesis
What are the two principal functions of ovaries listed in the notes?
Gametogenic function producing ova; endocrine function secreting estrogens, androgens, progesterone, inhibin, oocyte maturation factors, and IGF1
Only gametogenic function producing sperm; no endocrine secretion
Storing and releasing urine into the cloaca
Endocrine function producing only corticosteroids; no gametogenesis
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which description matches the agnathan testis anatomy in the notes?
Paired testes with well-defined gonoducts and seminal vesicles
No testes present; gametes produced externally from skin glands
Most primitive; single testis extending the body cavity length, no gonoducts
Testes with multiple lobes and direct discharge to urinary bladder
Which description matches the agnathan testis anatomy in the notes?
Paired testes with well-defined gonoducts and seminal vesicles
No testes present; gametes produced externally from skin glands
Most primitive; single testis extending the body cavity length, no gonoducts
Testes with multiple lobes and direct discharge to urinary bladder
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the sperm path for chondrichthyes as stated in the notes?
Testis → coelomic cavity → genital funnel → urinary duct → cloaca
Testis → single undifferentiated duct → external pores separate from urinary tract
Testis → epididymis → ductus deferens → seminal vesicle/sperm sac → cloaca (with urine and digestive waste)
Testis → oviduct → uterus → cloaca
What is the sperm path for chondrichthyes as stated in the notes?
Testis → coelomic cavity → genital funnel → urinary duct → cloaca
Testis → single undifferentiated duct → external pores separate from urinary tract
Testis → epididymis → ductus deferens → seminal vesicle/sperm sac → cloaca (with urine and digestive waste)
Testis → oviduct → uterus → cloaca
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In teleost fishes, what is the path sperm follow from production to exit?
Testis → epididymis → urethra
Testes → seminal duct → cloaca
Paired testes → gonoducts → gonopore
Testes → coelom → urinary duct
In teleost fishes, what is the path sperm follow from production to exit?
Testis → epididymis → urethra
Testes → seminal duct → cloaca
Paired testes → gonoducts → gonopore
Testes → coelom → urinary duct
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How are urinary and reproductive exits arranged in teleost fishes compared with sharks and amphibians?
Teleosts have greater separation with separate exits for sperm, kidneys, and reproductive tract
Teleosts release sperm into the coelom which exits via the urinary duct
Teleosts share a single exit for urine and sperm through the cloaca
Teleosts use the Wolffian duct to carry both urine and sperm
How are urinary and reproductive exits arranged in teleost fishes compared with sharks and amphibians?
Teleosts have greater separation with separate exits for sperm, kidneys, and reproductive tract
Teleosts release sperm into the coelom which exits via the urinary duct
Teleosts share a single exit for urine and sperm through the cloaca
Teleosts use the Wolffian duct to carry both urine and sperm
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In reptiles and birds, what does the Wolffian duct become and what is its role?
It becomes the oviduct carrying eggs to the cloaca
It becomes a urinary duct carrying both urine and sperm
It regresses and plays no role in adult reptiles and birds
It becomes the seminal duct (vas deferens) carrying only sperm to the cloaca, separating reproduction from urine
In reptiles and birds, what does the Wolffian duct become and what is its role?
It becomes the oviduct carrying eggs to the cloaca
It becomes a urinary duct carrying both urine and sperm
It regresses and plays no role in adult reptiles and birds
It becomes the seminal duct (vas deferens) carrying only sperm to the cloaca, separating reproduction from urine
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the typical sperm path in reptiles and birds from testis to exit?
Testis → epididymis → vas deferens (seminal duct) → cloaca
Testis → gonoducts → gonopore
Testis → urethra → urogenital opening
Testis → coelom → urinary duct → cloaca
What is the typical sperm path in reptiles and birds from testis to exit?
Testis → epididymis → vas deferens (seminal duct) → cloaca
Testis → gonoducts → gonopore
Testis → urethra → urogenital opening
Testis → coelom → urinary duct → cloaca
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Where is sperm primarily stored in reptiles versus birds?
Reptiles: epididymis. Birds: seminal sacs.
Reptiles: seminal sacs. Birds: epididymis
Reptiles: coelom. Birds: cloaca
Reptiles: vas deferens. Birds: oviduct
Where is sperm primarily stored in reptiles versus birds?
Reptiles: epididymis. Birds: seminal sacs.
Reptiles: seminal sacs. Birds: epididymis
Reptiles: coelom. Birds: cloaca
Reptiles: vas deferens. Birds: oviduct
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the sperm path in mammals from the testis to the urethra?
Testis → epididymis → cloaca
Testis → epididymis → vas (ductus) deferens → urethra
Testis → coelom → urinary duct
Testis → gonoducts → gonopore
What is the sperm path in mammals from the testis to the urethra?
Testis → epididymis → cloaca
Testis → epididymis → vas (ductus) deferens → urethra
Testis → coelom → urinary duct
Testis → gonoducts → gonopore
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which statement correctly contrasts testicondid and scrotal mammals as given in the text?
Both testicondid and scrotal mammals always have a cloaca
Testicondid mammals keep testes internal; scrotal mammals have external testes in a scrotum to reduce temperature
Testicondid mammals have external testes; scrotal mammals keep testes internal
All mammals are scrotal; testicondid is not a real category
Which statement correctly contrasts testicondid and scrotal mammals as given in the text?
Both testicondid and scrotal mammals always have a cloaca
Testicondid mammals keep testes internal; scrotal mammals have external testes in a scrotum to reduce temperature
Testicondid mammals have external testes; scrotal mammals keep testes internal
All mammals are scrotal; testicondid is not a real category
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which vertebrate group has mesonephric ducts modified as gonoducts (epididymis → ductus deferens)?
Amphibians
Chondrichthyes
Teleosts
Mammals
Which vertebrate group has mesonephric ducts modified as gonoducts (epididymis → ductus deferens)?
Amphibians
Chondrichthyes
Teleosts
Mammals
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which vertebrate group has dedicated gonoducts opening to a gonopore with separate exits for sperm, kidney, and gut?
Reptiles
Birds
Chondrichthyes
Teleosts
Which vertebrate group has dedicated gonoducts opening to a gonopore with separate exits for sperm, kidney, and gut?
Reptiles
Birds
Chondrichthyes
Teleosts
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In which group does the ductus deferens carry both sperm and urine, with both feeding into the cloaca?
Teleosts
Chondrichthyes
Mammals
Amphibians
In which group does the ductus deferens carry both sperm and urine, with both feeding into the cloaca?
Teleosts
Chondrichthyes
Mammals
Amphibians
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which group is described as having a sperm-only seminal duct while urinary and digestive systems still join at the cloaca?
Birds
Mammals
Teleosts
Chondrichthyes
Which group is described as having a sperm-only seminal duct while urinary and digestive systems still join at the cloaca?
Birds
Mammals
Teleosts
Chondrichthyes
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which group uses epididymis → vas deferens → urethra and lacks a cloaca?
Mammals
Birds
Reptiles
Amphibians
Which group uses epididymis → vas deferens → urethra and lacks a cloaca?
Mammals
Birds
Reptiles
Amphibians
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which group is internal and ectothermic, allowing the testes to remain inside the body?
Teleosts
Birds
Amphibians
Mammals
Which group is internal and ectothermic, allowing the testes to remain inside the body?
Teleosts
Birds
Amphibians
Mammals
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which statement about gonoducts across vertebrates is correct?
Gonoducts first appear only in mammals
Gonoducts are absent in agnathans and present in later vertebrate groups
Gonoducts are absent in all vertebrates
Gonoducts are present in agnathans but lost in higher vertebrates
Which statement about gonoducts across vertebrates is correct?
Gonoducts first appear only in mammals
Gonoducts are absent in agnathans and present in later vertebrate groups
Gonoducts are absent in all vertebrates
Gonoducts are present in agnathans but lost in higher vertebrates
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How does the separation of urinary and reproductive systems change over vertebrate evolution?
They become more separate over evolutionary time
They remain unchanged across all vertebrates
They become more combined over evolutionary time
They are separate only in fishes and recombine in tetrapods
How does the separation of urinary and reproductive systems change over vertebrate evolution?
They become more separate over evolutionary time
They remain unchanged across all vertebrates
They become more combined over evolutionary time
They are separate only in fishes and recombine in tetrapods
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Where are gonads typically located in ectothermic versus endothermic vertebrates?
Internal in ectotherms; moved nearer or to the body surface in endotherms as a cooling solution
External in ectotherms; internal in endotherms for insulation
Always external in both ectotherms and endotherms
Always internal in both ectotherms and endotherms
Where are gonads typically located in ectothermic versus endothermic vertebrates?
Internal in ectotherms; moved nearer or to the body surface in endotherms as a cooling solution
External in ectotherms; internal in endotherms for insulation
Always external in both ectotherms and endotherms
Always internal in both ectotherms and endotherms
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the functional reason many mammals have scrotal (external) testes?
To reduce temperature via vascular and molecular cooling mechanisms
To protect testes from predators
To reduce infection risk by exposure
To increase mating display visibility
What is the functional reason many mammals have scrotal (external) testes?
To reduce temperature via vascular and molecular cooling mechanisms
To protect testes from predators
To reduce infection risk by exposure
To increase mating display visibility
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What term describes species that retain internal testes rather than having scrotal testes?
Scrotal
Protandrous
Cloacal
Testicondid (internal testes)
What term describes species that retain internal testes rather than having scrotal testes?
Scrotal
Protandrous
Cloacal
Testicondid (internal testes)
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What are the three classical phases of spermatogenesis?
Proliferative, Secretory, Degenerative
Oogonial, Cleavage, Implantation
Spermatogonial (mitotic), Spermiation, Fertilization
Spermatogonial (mitotic), Meiotic, Spermiogenesis
What are the three classical phases of spermatogenesis?
Proliferative, Secretory, Degenerative
Oogonial, Cleavage, Implantation
Spermatogonial (mitotic), Spermiation, Fertilization
Spermatogonial (mitotic), Meiotic, Spermiogenesis
Bekijk hier je kaarten, of sign up to study with spaced repetition.
When does full, continuous spermatogenesis typically begin?
Around or after puberty when gonadotropins and sex steroids rise
Immediately at embryonic testis differentiation
At menopause
Only after first mating event
When does full, continuous spermatogenesis typically begin?
Around or after puberty when gonadotropins and sex steroids rise
Immediately at embryonic testis differentiation
At menopause
Only after first mating event
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which sequence correctly describes the HPG hormonal cascade regulating spermatogenesis?
GnRH → pituitary LH and FSH → LH to Leydig cells (androgens); FSH with androgens to Sertoli cells
Androgens → GnRH → FSH → Leydig cells
Pituitary directly produces androgens without LH or FSH
FSH → GnRH → LH → Sertoli cells only
Which sequence correctly describes the HPG hormonal cascade regulating spermatogenesis?
GnRH → pituitary LH and FSH → LH to Leydig cells (androgens); FSH with androgens to Sertoli cells
Androgens → GnRH → FSH → Leydig cells
Pituitary directly produces androgens without LH or FSH
FSH → GnRH → LH → Sertoli cells only
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What nuclear change occurs during spermiogenesis?
Nuclear envelope dissolves permanently
Nucleus enlarges and becomes transcriptionally active
Chromatin condenses dramatically so the nucleus becomes small and highly compact
Chromatin decondenses to allow increased gene expression
What nuclear change occurs during spermiogenesis?
Nuclear envelope dissolves permanently
Nucleus enlarges and becomes transcriptionally active
Chromatin condenses dramatically so the nucleus becomes small and highly compact
Chromatin decondenses to allow increased gene expression
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which morphological changes are characteristic of spermiogenesis?
Development of cilia instead of flagellum and increased cytoplasmic volume
Formation of extra nuclei, retention of large cytoplasm, random mitochondrial distribution
Formation of multiple tails and dispersed mitochondria
Acrosome formation, flagellum elongation, cytoplasm mostly shed, mitochondria cluster in midpiece
Which morphological changes are characteristic of spermiogenesis?
Development of cilia instead of flagellum and increased cytoplasmic volume
Formation of extra nuclei, retention of large cytoplasm, random mitochondrial distribution
Formation of multiple tails and dispersed mitochondria
Acrosome formation, flagellum elongation, cytoplasm mostly shed, mitochondria cluster in midpiece
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Where is the major sperm storage and maturation site in mammals, birds, and reptiles?
Epididymis
Uterus
Seminal vesicle/sperm sac
Oviduct
Where is the major sperm storage and maturation site in mammals, birds, and reptiles?
Epididymis
Uterus
Seminal vesicle/sperm sac
Oviduct
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In agnathans, what is the path of an ovulated ovum to the cloaca?
Ovulated ova → coelomic cavity → genital funnel → urinary duct → urogenital papilla → cloaca
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct → shell gland → cloaca
Ovulated ova → ovarian lumen → oviduct → uterus → cloaca
In agnathans, what is the path of an ovulated ovum to the cloaca?
Ovulated ova → coelomic cavity → genital funnel → urinary duct → urogenital papilla → cloaca
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct → shell gland → cloaca
Ovulated ova → ovarian lumen → oviduct → uterus → cloaca
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which feature is a similarity between male and female agnathans?
Both use an external oviduct (Müllerian duct) for gamete passage
Both sexes have paired gonads located in the pelvic region
Both have separate dedicated gonoducts connecting gonads directly to cloaca
Both have a single gonad extending along the body cavity and use the coelomic cavity → genital funnel → urinary duct → cloaca for gamete release
Which feature is a similarity between male and female agnathans?
Both use an external oviduct (Müllerian duct) for gamete passage
Both sexes have paired gonads located in the pelvic region
Both have separate dedicated gonoducts connecting gonads directly to cloaca
Both have a single gonad extending along the body cavity and use the coelomic cavity → genital funnel → urinary duct → cloaca for gamete release
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is a typical difference between oviparous and viviparous chondrichthyan ovaries?
Oviparous species usually have one ovary, whereas viviparous species have two functional ovaries
Viviparous species lack ovaries and develop eggs in the liver
Both oviparous and viviparous species always have two ovaries
Oviparous species usually have two ovaries, whereas viviparous species usually have one (right) ovary
What is a typical difference between oviparous and viviparous chondrichthyan ovaries?
Oviparous species usually have one ovary, whereas viviparous species have two functional ovaries
Viviparous species lack ovaries and develop eggs in the liver
Both oviparous and viviparous species always have two ovaries
Oviparous species usually have two ovaries, whereas viviparous species usually have one (right) ovary
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In chondrichthyans, through which sequence does an ovulated egg pass before reaching the cloaca?
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct (Müllerian duct) → shell gland → uterus (if viviparous) → cloaca
Ovulated ova → coelomic cavity → infundibulum → oviduct → vagina → cloaca
Ovulated ova → coelomic cavity → genital funnel → urinary duct → cloaca
In chondrichthyans, through which sequence does an ovulated egg pass before reaching the cloaca?
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct (Müllerian duct) → shell gland → uterus (if viviparous) → cloaca
Ovulated ova → coelomic cavity → infundibulum → oviduct → vagina → cloaca
Ovulated ova → coelomic cavity → genital funnel → urinary duct → cloaca
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How do teleost ovaries typically release eggs compared with sharks?
Teleosts use a true Müllerian duct system like sharks
Teleost eggs are retained in a uterus until hatching
Teleost eggs are released into the coelomic cavity then pass through ostia to a Müllerian oviduct
Teleost eggs are released into the ovarian lumen (not the coelom) and pass via an ovarian duct to the outside
How do teleost ovaries typically release eggs compared with sharks?
Teleosts use a true Müllerian duct system like sharks
Teleost eggs are retained in a uterus until hatching
Teleost eggs are released into the coelomic cavity then pass through ostia to a Müllerian oviduct
Teleost eggs are released into the ovarian lumen (not the coelom) and pass via an ovarian duct to the outside
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which oviduct region in birds and reptiles is primarily responsible for albumen (egg white) secretion?
Isthmus
Infundibulum
Magnum
Uterus
Which oviduct region in birds and reptiles is primarily responsible for albumen (egg white) secretion?
Isthmus
Infundibulum
Magnum
Uterus
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the normal path of an ovulated mammalian ovum from ovulation to exit?
Coelomic cavity → uterus → fallopian tube → cervix → vagina
Ovarian lumen → infundibulum → uterus → vagina → cervix
Coelomic cavity → infundibulum with fimbriae → fallopian tube → uterus → cervix → vagina
Infundibulum → coelomic cavity → fallopian tube → uterus → vagina
What is the normal path of an ovulated mammalian ovum from ovulation to exit?
Coelomic cavity → uterus → fallopian tube → cervix → vagina
Ovarian lumen → infundibulum → uterus → vagina → cervix
Coelomic cavity → infundibulum with fimbriae → fallopian tube → uterus → cervix → vagina
Infundibulum → coelomic cavity → fallopian tube → uterus → vagina
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which uterine type has two completely separate horns and two cervices, often associated with large litters?
Simplex
Bicornuate
Bipartite
Duplex
Which uterine type has two completely separate horns and two cervices, often associated with large litters?
Simplex
Bicornuate
Bipartite
Duplex
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which uterine form has no horns, a single uterine cavity, one cervix, and is associated with centralized implantation and single offspring?
Bipartite
Simplex
Duplex
Bicornuate
Which uterine form has no horns, a single uterine cavity, one cervix, and is associated with centralized implantation and single offspring?
Bipartite
Simplex
Duplex
Bicornuate
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Into where do teleost fishes typically ovulate?
Infundibulum with fimbriae
Oviduct derived from Müllerian duct
Coelomic cavity
Ovarian lumen
Into where do teleost fishes typically ovulate?
Infundibulum with fimbriae
Oviduct derived from Müllerian duct
Coelomic cavity
Ovarian lumen
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which structure gives rise to oviducts (shell gland, uterus, etc.) in reptiles, birds, and mammals?
Coelomic epithelium
Müllerian ducts
Ovarian lumen/gonoduct
Wolffian ducts
Which structure gives rise to oviducts (shell gland, uterus, etc.) in reptiles, birds, and mammals?
Coelomic epithelium
Müllerian ducts
Ovarian lumen/gonoduct
Wolffian ducts
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How many functional ovaries do most adult birds and most mammals have, respectively?
Birds: one (right); Mammals: one
Birds: one (typically left); Mammals: two
Birds: two; Mammals: one
Birds: paired masses of follicles; Mammals: paired in some, single in others
How many functional ovaries do most adult birds and most mammals have, respectively?
Birds: one (right); Mammals: one
Birds: one (typically left); Mammals: two
Birds: two; Mammals: one
Birds: paired masses of follicles; Mammals: paired in some, single in others
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which new characteristic is listed for amniotes regarding eggs and oviduct specialization?
Amniotic egg with four extraembryonic membranes and regional oviduct specialization
Single functional ovary and loss of fimbriae
Ovarian lumen ovulation and absence of Müllerian ducts
Placenta replaces albumen and no oviduct regions
Which new characteristic is listed for amniotes regarding eggs and oviduct specialization?
Amniotic egg with four extraembryonic membranes and regional oviduct specialization
Single functional ovary and loss of fimbriae
Ovarian lumen ovulation and absence of Müllerian ducts
Placenta replaces albumen and no oviduct regions
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What new reproductive characteristic is specified for mammals compared to other amniotes?
Amniotic egg with four membranes
Ovarian duct replaces Müllerian duct
Placenta replaces shell/albumen and uterus specialized for implantation
Ovulation into ovarian lumen
What new reproductive characteristic is specified for mammals compared to other amniotes?
Amniotic egg with four membranes
Ovarian duct replaces Müllerian duct
Placenta replaces shell/albumen and uterus specialized for implantation
Ovulation into ovarian lumen
Bekijk hier je kaarten, of sign up to study with spaced repetition.
When does spermatogenesis begin in human males?
Begins during embryonic development and pauses until puberty
Is completed before birth and remains inactive until puberty
Starts only after first ejaculation in adulthood
Around puberty and continues throughout reproductive life
When does spermatogenesis begin in human males?
Begins during embryonic development and pauses until puberty
Is completed before birth and remains inactive until puberty
Starts only after first ejaculation in adulthood
Around puberty and continues throughout reproductive life
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which statement correctly describes the female oocyte pool timing and numbers?
Massive oocyte pool forms embryonically (~3 million per ovary → ~1 million at birth → ~250,000 at puberty)
Oocyte pool forms at puberty and reaches ~3 million per ovary then declines
Oocytes are produced continuously after puberty increasing numbers over time
No oocytes are present at birth; all develop after puberty
Which statement correctly describes the female oocyte pool timing and numbers?
Massive oocyte pool forms embryonically (~3 million per ovary → ~1 million at birth → ~250,000 at puberty)
Oocyte pool forms at puberty and reaches ~3 million per ovary then declines
Oocytes are produced continuously after puberty increasing numbers over time
No oocytes are present at birth; all develop after puberty
Bekijk hier je kaarten, of sign up to study with spaced repetition.
When does meiosis I of oocytes occur and complete in human females?
Begins and completes entirely after fertilization
Begins at puberty and completes only after menopause
Begins during embryonic development and completes before birth
Begins during embryonic development, pauses, and is completed just before ovulation
When does meiosis I of oocytes occur and complete in human females?
Begins and completes entirely after fertilization
Begins at puberty and completes only after menopause
Begins during embryonic development and completes before birth
Begins during embryonic development, pauses, and is completed just before ovulation
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which event triggers completion of meiosis II in the human oocyte?
Ovulation alone
Fertilization
Attachment to the uterine wall
LH surge without fertilization
Which event triggers completion of meiosis II in the human oocyte?
Ovulation alone
Fertilization
Attachment to the uterine wall
LH surge without fertilization
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the primary endocrine role of the pituitary in folliculogenesis?
Secretion of progesterone from the corpus luteum
Production of androgens by theca cells
Direct conversion of androgens to estrogens within follicles
Release of LH and FSH in response to hypothalamic GnRH pulses
What is the primary endocrine role of the pituitary in folliculogenesis?
Secretion of progesterone from the corpus luteum
Production of androgens by theca cells
Direct conversion of androgens to estrogens within follicles
Release of LH and FSH in response to hypothalamic GnRH pulses
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which function is attributed to theca cells during follicle development?
Nourish the oocyte and produce estrogen directly
Provide structural support and produce androgens for granulosa conversion
Trigger GnRH release from the hypothalamus
Form the corpus luteum after ovulation and secrete progesterone
Which function is attributed to theca cells during follicle development?
Nourish the oocyte and produce estrogen directly
Provide structural support and produce androgens for granulosa conversion
Trigger GnRH release from the hypothalamus
Form the corpus luteum after ovulation and secrete progesterone
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which roles do granulosa cells perform in the ovarian follicle?
Produce androgens as the primary endocrine product
Nourish the oocyte, produce estrogens and factors, and later contribute to corpus luteum
Act only as passive structural cells with no hormonal role
Secrete GnRH to stimulate the pituitary
Which roles do granulosa cells perform in the ovarian follicle?
Produce androgens as the primary endocrine product
Nourish the oocyte, produce estrogens and factors, and later contribute to corpus luteum
Act only as passive structural cells with no hormonal role
Secrete GnRH to stimulate the pituitary
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the main endocrine function of the corpus luteum after ovulation?
Secrete progesterone to prepare the uterus for implantation and inhibit GnRH
Secrete FSH and LH to promote new follicular waves
Convert progesterone into estrogens to trigger ovulation
Produce androgens to stimulate follicle growth
What is the main endocrine function of the corpus luteum after ovulation?
Secrete progesterone to prepare the uterus for implantation and inhibit GnRH
Secrete FSH and LH to promote new follicular waves
Convert progesterone into estrogens to trigger ovulation
Produce androgens to stimulate follicle growth
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which two key timing contrasts differentiate male and female gametogenesis?
Male starts embryonically and pauses until puberty; female starts at puberty and continues continuously
Male oocyte number is fixed early; female sperm production is continuous
Both male and female gametogenesis start at puberty and proceed continuously
Male starts at puberty and is continuous; female starts embryonically and oocyte number is fixed early and declines
Which two key timing contrasts differentiate male and female gametogenesis?
Male starts embryonically and pauses until puberty; female starts at puberty and continues continuously
Male oocyte number is fixed early; female sperm production is continuous
Both male and female gametogenesis start at puberty and proceed continuously
Male starts at puberty and is continuous; female starts embryonically and oocyte number is fixed early and declines
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What immediately triggers the oocyte to complete meiosis I and be released during ovulation?
LH surge
Progesterone peak
FSH surge
GnRH surge
What immediately triggers the oocyte to complete meiosis I and be released during ovulation?
LH surge
Progesterone peak
FSH surge
GnRH surge
Bekijk hier je kaarten, of sign up to study with spaced repetition.
When does meiosis I and meiosis II occur in oogenesis?
Both meioses are completed at sexual maturity regardless of fertilization
Meiosis I completes at fertilization; meiosis II completes at ovulation
Meiosis I and II both complete before birth
Meiosis I begins embryonically and completes just before ovulation; meiosis II completes only if fertilization occurs
When does meiosis I and meiosis II occur in oogenesis?
Both meioses are completed at sexual maturity regardless of fertilization
Meiosis I completes at fertilization; meiosis II completes at ovulation
Meiosis I and II both complete before birth
Meiosis I begins embryonically and completes just before ovulation; meiosis II completes only if fertilization occurs
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What primarily drives the onset of ovarian cycles at sexual maturity?
Sustained high estrogen secretion from ovaries
Increase in pulsatile GnRH production and secretion from the hypothalamus
Continuous LH elevation from the pituitary
Persistent photoperiod/seasonal cues alone
What primarily drives the onset of ovarian cycles at sexual maturity?
Sustained high estrogen secretion from ovaries
Increase in pulsatile GnRH production and secretion from the hypothalamus
Continuous LH elevation from the pituitary
Persistent photoperiod/seasonal cues alone
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How are ovarian cycles subsequently regulated after onset?
Only estrogens regulate the cycle without LH or FSH involvement
GnRH stimulates pituitary LH and FSH; ovarian estrogens, progesterone, and androgens feedback on hypothalamus/pituitary
Ovarian cycles run independently of hypothalamic or pituitary hormones
Pituitary hormones inhibit GnRH and stop ovarian hormone production
How are ovarian cycles subsequently regulated after onset?
Only estrogens regulate the cycle without LH or FSH involvement
GnRH stimulates pituitary LH and FSH; ovarian estrogens, progesterone, and androgens feedback on hypothalamus/pituitary
Ovarian cycles run independently of hypothalamic or pituitary hormones
Pituitary hormones inhibit GnRH and stop ovarian hormone production
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which statement best describes sexual receptivity differences between estrus and menstrual cycles?
In estrus cycles receptivity is continuous; in menstrual cycles receptivity occurs only at ovulation
Both estrus and menstrual cycles have receptivity only during a brief heat period
In estrus cycles receptivity is restricted to estrus coinciding with ovulation; in menstrual cycles receptivity is essentially continuous
Neither cycle type shows any hormonal influence on receptivity
Which statement best describes sexual receptivity differences between estrus and menstrual cycles?
In estrus cycles receptivity is continuous; in menstrual cycles receptivity occurs only at ovulation
Both estrus and menstrual cycles have receptivity only during a brief heat period
In estrus cycles receptivity is restricted to estrus coinciding with ovulation; in menstrual cycles receptivity is essentially continuous
Neither cycle type shows any hormonal influence on receptivity
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is a distinguishing feature of menstrual cycles not present in broad estrus cycles?
Sexual receptivity restricted to a brief heat period
Endometrial sloughing (menses) if no pregnancy
No involvement of estrogen or progesterone
Ovulation does not occur
What is a distinguishing feature of menstrual cycles not present in broad estrus cycles?
Sexual receptivity restricted to a brief heat period
Endometrial sloughing (menses) if no pregnancy
No involvement of estrogen or progesterone
Ovulation does not occur
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which hormone stimulates endometrial growth during the proliferative phase?
Progesterone from corpus luteum
Estrogen from developing follicles
Prostaglandins from endometrium
FSH from pituitary
Which hormone stimulates endometrial growth during the proliferative phase?
Progesterone from corpus luteum
Estrogen from developing follicles
Prostaglandins from endometrium
FSH from pituitary
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the primary endometrial effect of progesterone in the secretory phase?
Causes ischemic necrosis of the functional layer
Increases prostaglandin production leading to contractions
Converts endometrium to glandular, secretory tissue suitable for implantation
Stimulates endometrial proliferation and progesterone receptor expression
What is the primary endometrial effect of progesterone in the secretory phase?
Causes ischemic necrosis of the functional layer
Increases prostaglandin production leading to contractions
Converts endometrium to glandular, secretory tissue suitable for implantation
Stimulates endometrial proliferation and progesterone receptor expression
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What sequence leads to menstrual phase when there is no pregnancy?
Estrogen rise → progesterone rise → increased vascularization
Corpus luteum persists → high estrogen and progesterone → menstruation
Corpus luteum regression → estrogen and progesterone drop → prostaglandins increase
Prostaglandin decrease → vasodilation → shedding
What sequence leads to menstrual phase when there is no pregnancy?
Estrogen rise → progesterone rise → increased vascularization
Corpus luteum persists → high estrogen and progesterone → menstruation
Corpus luteum regression → estrogen and progesterone drop → prostaglandins increase
Prostaglandin decrease → vasodilation → shedding
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How do prostaglandins contribute to menstrual bleeding?
They stimulate progesterone production to maintain the endometrium
They directly dissolve endometrial glands without affecting blood flow
They cause vasoconstriction of endometrial vessels leading to ischemic necrosis of the functional layer
They inhibit myometrial contractions preventing tissue expulsion
How do prostaglandins contribute to menstrual bleeding?
They stimulate progesterone production to maintain the endometrium
They directly dissolve endometrial glands without affecting blood flow
They cause vasoconstriction of endometrial vessels leading to ischemic necrosis of the functional layer
They inhibit myometrial contractions preventing tissue expulsion
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the main cause of primary dysmenorrhea?
Structural obstruction by pelvic adhesions
Ectopic endometrial tissue outside the uterus
Benign smooth muscle tumors of the uterus
Excess prostaglandin production in the endometrium causing excessive uterine contractions
What is the main cause of primary dysmenorrhea?
Structural obstruction by pelvic adhesions
Ectopic endometrial tissue outside the uterus
Benign smooth muscle tumors of the uterus
Excess prostaglandin production in the endometrium causing excessive uterine contractions
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which treatment is recommended for primary dysmenorrhea in the text?
Antibiotics to reduce pelvic infection
Progesterone receptor blockers
Surgical removal of uterine fibroids
NSAIDs that block prostaglandin production
Which treatment is recommended for primary dysmenorrhea in the text?
Antibiotics to reduce pelvic infection
Progesterone receptor blockers
Surgical removal of uterine fibroids
NSAIDs that block prostaglandin production
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which conditions are cited as causes of secondary dysmenorrhea?
Ectopic pregnancy and choriocarcinoma
Primary excess prostaglandins only
Ovarian failure and menopause
Endometriosis and uterine fibroids
Which conditions are cited as causes of secondary dysmenorrhea?
Ectopic pregnancy and choriocarcinoma
Primary excess prostaglandins only
Ovarian failure and menopause
Endometriosis and uterine fibroids
Bekijk hier je kaarten, of sign up to study with spaced repetition.
According to the lecture hypothesis, how did concealed ovulation and continuous receptivity affect human social evolution?
They increased male detection of fertile periods, reducing pair bonding
They caused frequent large-scale migrations of human groups
They kept males close to mates, promoting long-term pair bonds and more permanent social groupings
They eliminated the need for cooperative hunting
According to the lecture hypothesis, how did concealed ovulation and continuous receptivity affect human social evolution?
They increased male detection of fertile periods, reducing pair bonding
They caused frequent large-scale migrations of human groups
They kept males close to mates, promoting long-term pair bonds and more permanent social groupings
They eliminated the need for cooperative hunting
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which statement best describes external fertilization in vertebrates?
Sperm are deposited directly into the female reproductive tract
Gametes are retained and fertilized within a nest or burrow exclusively
Gametes are released directly into water, as in many bony fishes and amphibians
Fertilization occurs inside a protective egg membrane within the female
Which statement best describes external fertilization in vertebrates?
Sperm are deposited directly into the female reproductive tract
Gametes are retained and fertilized within a nest or burrow exclusively
Gametes are released directly into water, as in many bony fishes and amphibians
Fertilization occurs inside a protective egg membrane within the female
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What are two main problems associated with external fertilization listed in the notes?
Delayed ovulation and cryptic female choice
Sperm competition within the female tract and need for copulatory organs
Requirement for internal membranes and placental transfer
Gametes disperse before fertilization and osmoregulatory stress from environment
What are two main problems associated with external fertilization listed in the notes?
Delayed ovulation and cryptic female choice
Sperm competition within the female tract and need for copulatory organs
Requirement for internal membranes and placental transfer
Gametes disperse before fertilization and osmoregulatory stress from environment
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which solution is described for reducing gamete dispersal during external fertilization?
Group spawning or synchronized release to keep gametes concentrated
Using copulatory organs to deposit sperm in the female tract
Storing sperm in the epididymis for months
Temperature-dependent sex determination to time mating
Which solution is described for reducing gamete dispersal during external fertilization?
Group spawning or synchronized release to keep gametes concentrated
Using copulatory organs to deposit sperm in the female tract
Storing sperm in the epididymis for months
Temperature-dependent sex determination to time mating
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How do vitelline layers help external eggs according to the notes?
They enclose eggs in protective membranes that resist osmotic change
They store sperm for later fertilization
They actively pump salts to equalize internal and external osmolarity
They function as copulatory organs for sperm transfer
How do vitelline layers help external eggs according to the notes?
They enclose eggs in protective membranes that resist osmotic change
They store sperm for later fertilization
They actively pump salts to equalize internal and external osmolarity
They function as copulatory organs for sperm transfer
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which feature characterizes internal fertilization as listed in the notes?
Sperm are deposited directly in the female tract, occurring in reptiles, birds, mammals
Gametes are released into the water and fertilize externally
Eggs are always enclosed in vitelline layers before fertilization
Fertilization requires synchronized group spawning
Which feature characterizes internal fertilization as listed in the notes?
Sperm are deposited directly in the female tract, occurring in reptiles, birds, mammals
Gametes are released into the water and fertilize externally
Eggs are always enclosed in vitelline layers before fertilization
Fertilization requires synchronized group spawning
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What solution is noted for ensuring sperm reach eggs in internal fertilization?
Enclosing eggs in vitelline layers to resist osmotic change
Synchronized external release of gametes
Storing sperm in female oviductal sites only
Use of copulatory organs and specialized ducts for direct transfer
What solution is noted for ensuring sperm reach eggs in internal fertilization?
Enclosing eggs in vitelline layers to resist osmotic change
Synchronized external release of gametes
Storing sperm in female oviductal sites only
Use of copulatory organs and specialized ducts for direct transfer
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which is a listed advantage of sperm storage?
Prevents any possibility of sperm competition
Allows separation of mating from fertilization in time
Removes requirement for specialized anatomical adaptations
Eliminates need for ovulation entirely
Which is a listed advantage of sperm storage?
Prevents any possibility of sperm competition
Allows separation of mating from fertilization in time
Removes requirement for specialized anatomical adaptations
Eliminates need for ovulation entirely
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which disadvantage of sperm storage is mentioned in the notes?
Always causes immediate fertilization upon storage
Prevents females from controlling paternity
Requires specialized anatomical and physiological adaptations to maintain sperm viability
Removes the need for seasonal breeding timing
Which disadvantage of sperm storage is mentioned in the notes?
Always causes immediate fertilization upon storage
Prevents females from controlling paternity
Requires specialized anatomical and physiological adaptations to maintain sperm viability
Removes the need for seasonal breeding timing
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which example of sperm storage location is explicitly given in the notes?
All females store sperm in ovaries only
Sperm are stored in external nests until fertilization
Sperm are stored exclusively in the vitelline layer
Some males store sperm within the epididymis
Which example of sperm storage location is explicitly given in the notes?
All females store sperm in ovaries only
Sperm are stored in external nests until fertilization
Sperm are stored exclusively in the vitelline layer
Some males store sperm within the epididymis
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Where does sperm capacitation occur in mammals?
Testes seminiferous tubules
Male epididymis
Vagina only
Female reproductive tract (uterus and oviduct)
Where does sperm capacitation occur in mammals?
Testes seminiferous tubules
Male epididymis
Vagina only
Female reproductive tract (uterus and oviduct)
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which change is a key outcome of capacitation that readies sperm for fertilization?
Formation of the zona pellucida
Hyperactivated motility and increased acrosome readiness
Fusion of pronuclei
Completion of sperm meiosis
Which change is a key outcome of capacitation that readies sperm for fertilization?
Formation of the zona pellucida
Hyperactivated motility and increased acrosome readiness
Fusion of pronuclei
Completion of sperm meiosis
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which molecular sequence during capacitation leads to increased sperm Ca2+ sensitivity?
Cholesterol addition to membrane → decreased motility
Exposure to Ca2+ and HCO3¯ → increased cAMP → phosphorylation cascades
Removal of Ca2+ and HCO3¯ → decreased cAMP → phosphorylation cascades
Direct progesterone binding to DNA → transcriptional changes
Which molecular sequence during capacitation leads to increased sperm Ca2+ sensitivity?
Cholesterol addition to membrane → decreased motility
Exposure to Ca2+ and HCO3¯ → increased cAMP → phosphorylation cascades
Removal of Ca2+ and HCO3¯ → decreased cAMP → phosphorylation cascades
Direct progesterone binding to DNA → transcriptional changes
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What triggers the acrosome reaction after capacitation?
Fusion of pronuclei
Completion of the egg's second meiotic division
Sperm binding to zona pellucida glycoproteins such as ZP2 and ZP3
Progesterone binding to egg plasma membrane receptors
What triggers the acrosome reaction after capacitation?
Fusion of pronuclei
Completion of the egg's second meiotic division
Sperm binding to zona pellucida glycoproteins such as ZP2 and ZP3
Progesterone binding to egg plasma membrane receptors
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How do differences in acrosome structure across species affect fertilization strategy?
Acrosome shape only affects sperm motility, not penetration strategy
All species use identical enzymatic strategies regardless of acrosome shape
Species with a fibrous core rely more on mechanical penetration; species without it rely more on enzymes
Species with a fibrous core cannot undergo the acrosome reaction
How do differences in acrosome structure across species affect fertilization strategy?
Acrosome shape only affects sperm motility, not penetration strategy
All species use identical enzymatic strategies regardless of acrosome shape
Species with a fibrous core rely more on mechanical penetration; species without it rely more on enzymes
Species with a fibrous core cannot undergo the acrosome reaction
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is a key difference between mammalian and avian fertilization regarding sperm entry?
Mammals require multiple sperm nuclei to form the zygote
Mammals typically prevent multiple sperm fusion; birds allow physiological polyspermy but restrict multiple sperm nuclei from participating
Birds prevent any sperm from entering the egg cytoplasm
Birds fuse all entering sperm nuclei to form a polyploid zygote
What is a key difference between mammalian and avian fertilization regarding sperm entry?
Mammals require multiple sperm nuclei to form the zygote
Mammals typically prevent multiple sperm fusion; birds allow physiological polyspermy but restrict multiple sperm nuclei from participating
Birds prevent any sperm from entering the egg cytoplasm
Birds fuse all entering sperm nuclei to form a polyploid zygote
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which reproductive mode is characterized by laying yolk-filled eggs into the external environment with yolk synthesized in the liver during vitellogenesis?
Parthenogenetic
Ovoviviparous
Viviparous
Oviparous
Which reproductive mode is characterized by laying yolk-filled eggs into the external environment with yolk synthesized in the liver during vitellogenesis?
Parthenogenetic
Ovoviviparous
Viviparous
Oviparous
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which developmental provisioning mode retains eggs within the uterus, with embryos primarily nourished by yolk but sometimes supplemented by uterine secretions or a quasi-placenta?
Aplacental
Viviparous
Oviparous
Ovoviviparous
Which developmental provisioning mode retains eggs within the uterus, with embryos primarily nourished by yolk but sometimes supplemented by uterine secretions or a quasi-placenta?
Aplacental
Viviparous
Oviparous
Ovoviviparous
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which reproductive mode involves internal development with maternal nutrient supply via a true placenta where fetal and maternal circulations meet in a common capillary bed?
Viviparous
Ovoviviparous
Oviparous
Ovo-viviparous
Which reproductive mode involves internal development with maternal nutrient supply via a true placenta where fetal and maternal circulations meet in a common capillary bed?
Viviparous
Ovoviviparous
Oviparous
Ovo-viviparous
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In the classic amniotic egg, which extraembryonic membrane directly encases and cushions the embryo and prevents desiccation?
Yolk sac
Allantois
Chorion
Amnion
In the classic amniotic egg, which extraembryonic membrane directly encases and cushions the embryo and prevents desiccation?
Yolk sac
Allantois
Chorion
Amnion
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which extraembryonic membrane in the classic amniotic egg stores metabolic wastes like uric acid and also participates in gas exchange?
Allantois
Yolk sac
Chorion
Amnion
Which extraembryonic membrane in the classic amniotic egg stores metabolic wastes like uric acid and also participates in gas exchange?
Allantois
Yolk sac
Chorion
Amnion
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In eutherian (placental) mammals, what does the chorion represent?
The umbilical cord and placental vessels
The fetal portion of the placenta
The yolk-containing nutrition sac
A fluid-filled cavity that cushions the embryo
In eutherian (placental) mammals, what does the chorion represent?
The umbilical cord and placental vessels
The fetal portion of the placenta
The yolk-containing nutrition sac
A fluid-filled cavity that cushions the embryo
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which of the following is NOT one of the three main types of changes during embryonic development listed in the notes?
Morphogenesis
Growth
Apoptosis
Differentiation
Which of the following is NOT one of the three main types of changes during embryonic development listed in the notes?
Morphogenesis
Growth
Apoptosis
Differentiation
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which developmental process involves cells becoming specialized for different functions such as muscle, neuron, or epithelium?
Morphogenesis
Growth
Differentiation
Fertilization
Which developmental process involves cells becoming specialized for different functions such as muscle, neuron, or epithelium?
Morphogenesis
Growth
Differentiation
Fertilization
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the defining characteristic of cleavage after fertilization in vertebrates?
Immediate formation of differentiated tissues without a blastula stage
Fusion of cells to form a syncytium rather than separate blastomeres
Slow cell divisions with substantial embryo growth before cell number increases
Rapid cell divisions with little or no overall growth, producing a blastula
What is the defining characteristic of cleavage after fertilization in vertebrates?
Immediate formation of differentiated tissues without a blastula stage
Fusion of cells to form a syncytium rather than separate blastomeres
Slow cell divisions with substantial embryo growth before cell number increases
Rapid cell divisions with little or no overall growth, producing a blastula
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How does yolk distribution between the animal and vegetal poles affect cleavage?
Yolk distribution has no effect on cleavage speed or cell number
More yolk at the vegetal pole causes slower or incomplete divisions there and more cells at the animal pole
Even yolk distribution leads to incomplete divisions only at the animal pole
More yolk at the animal pole causes faster divisions at the vegetal pole
How does yolk distribution between the animal and vegetal poles affect cleavage?
Yolk distribution has no effect on cleavage speed or cell number
More yolk at the vegetal pole causes slower or incomplete divisions there and more cells at the animal pole
Even yolk distribution leads to incomplete divisions only at the animal pole
More yolk at the animal pole causes faster divisions at the vegetal pole
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What consequence does the animal-vegetal polarity help establish during early development?
Immediate organogenesis without gastrulation
Complete symmetry with no axis formation
Body axes and influence on later gastrulation movements
Formation of extraembryonic membranes only
What consequence does the animal-vegetal polarity help establish during early development?
Immediate organogenesis without gastrulation
Complete symmetry with no axis formation
Body axes and influence on later gastrulation movements
Formation of extraembryonic membranes only
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In the Dai et al. coincubation study, how did short (4 h) versus standard (16–18 h) sperm-oocyte coincubation affect fertilization with normal sperm?
Fertilization, embryo quality, clinical pregnancy, and implantation rates were similar for short and standard coincubation
Short coincubation eliminated implantation despite similar fertilization
Short coincubation greatly increased fertilization rates compared with standard
Standard coincubation caused significantly worse embryo quality with normal sperm
In the Dai et al. coincubation study, how did short (4 h) versus standard (16–18 h) sperm-oocyte coincubation affect fertilization with normal sperm?
Fertilization, embryo quality, clinical pregnancy, and implantation rates were similar for short and standard coincubation
Short coincubation eliminated implantation despite similar fertilization
Short coincubation greatly increased fertilization rates compared with standard
Standard coincubation caused significantly worse embryo quality with normal sperm
Bekijk hier je kaarten, of sign up to study with spaced repetition.
How did short (4 h) coincubation affect fertilization rates when a mild male factor was present in the Dai et al. study?
Short coincubation had no impact on fertilization rate with mild male factor
Short coincubation improved embryo quality but lowered pregnancy rates
Short coincubation increased fertilization rate to above 80%
Short coincubation significantly reduced fertilization rate (62.6%) versus standard (68.7%)
How did short (4 h) coincubation affect fertilization rates when a mild male factor was present in the Dai et al. study?
Short coincubation had no impact on fertilization rate with mild male factor
Short coincubation improved embryo quality but lowered pregnancy rates
Short coincubation increased fertilization rate to above 80%
Short coincubation significantly reduced fertilization rate (62.6%) versus standard (68.7%)
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is 'rescue ICSI' as described in the notes?
Performing ICSI on oocytes that failed to show signs of fertilization after initial IVF insemination
A method of fertilizing eggs using donor sperm after failed IVF
A technique to rescue damaged sperm before insemination
Using ICSI before any IVF insemination to prevent fertilization failure
What is 'rescue ICSI' as described in the notes?
Performing ICSI on oocytes that failed to show signs of fertilization after initial IVF insemination
A method of fertilizing eggs using donor sperm after failed IVF
A technique to rescue damaged sperm before insemination
Using ICSI before any IVF insemination to prevent fertilization failure
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is the primary purpose of performing rescue ICSI when no second polar body is seen at 4–6 h?
To increase implantation rates for all IVF patients regardless of sperm quality
To prevent complete fertilization failure in IVF cycles, especially when sperm parameters are poor (mild male factor)
To replace embryo transfer with earlier cryopreservation
To reduce polyspermy in cycles with normal sperm parameters
What is the primary purpose of performing rescue ICSI when no second polar body is seen at 4–6 h?
To increase implantation rates for all IVF patients regardless of sperm quality
To prevent complete fertilization failure in IVF cycles, especially when sperm parameters are poor (mild male factor)
To replace embryo transfer with earlier cryopreservation
To reduce polyspermy in cycles with normal sperm parameters
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What fertilization rate was reported after rescue ICSI in the study?
62.6%
68.7%
71.3%
34.7%
What fertilization rate was reported after rescue ICSI in the study?
62.6%
68.7%
71.3%
34.7%
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which polyspermy rate was observed after rescue ICSI in the study?
24.1%
7.3%
4.1%
3.2%
Which polyspermy rate was observed after rescue ICSI in the study?
24.1%
7.3%
4.1%
3.2%
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In cycles with normal sperm (Group I), how did 4 h coincubation compare with 16–18 h for polyspermy?
Polyspermy was eliminated with 4 h coincubation
Polyspermy rate was significantly higher with 4 h (7.3%) than with 16–18 h (4.1%)
Polyspermy rate was significantly lower with 4 h than with 16–18 h
There was no significant difference in polyspermy between 4 h and 16–18 h
In cycles with normal sperm (Group I), how did 4 h coincubation compare with 16–18 h for polyspermy?
Polyspermy was eliminated with 4 h coincubation
Polyspermy rate was significantly higher with 4 h (7.3%) than with 16–18 h (4.1%)
Polyspermy rate was significantly lower with 4 h than with 16–18 h
There was no significant difference in polyspermy between 4 h and 16–18 h
Bekijk hier je kaarten, of sign up to study with spaced repetition.
In cycles with mild male factor (Group II), what effect did shortening coincubation to 4 h have on fertilization rate?
Fertilization rate was significantly higher with 4 h than with 16–18 h
4 h coincubation improved clinical pregnancy rates compared with 16–18 h
There was no significant difference in fertilization rate between 4 h and 16–18 h
Fertilization rate was significantly lower with 4 h (62.6%) than with 16–18 h (68.7%)
In cycles with mild male factor (Group II), what effect did shortening coincubation to 4 h have on fertilization rate?
Fertilization rate was significantly higher with 4 h than with 16–18 h
4 h coincubation improved clinical pregnancy rates compared with 16–18 h
There was no significant difference in fertilization rate between 4 h and 16–18 h
Fertilization rate was significantly lower with 4 h (62.6%) than with 16–18 h (68.7%)
Bekijk hier je kaarten, of sign up to study with spaced repetition.
Which overall conclusion about coincubation time and rescue ICSI is supported by the study?
With normal sperm, changing 4 h vs 16–18 h does not affect fertilization or pregnancy but can increase polyspermy; with mild male factor, 4 h lowers fertilization and combining 4 h with early rescue ICSI can avoid complete fertilization failure
Shortening coincubation to 4 h uniformly improves fertilization and pregnancy outcomes for all sperm qualities
Rescue ICSI eliminated polyspermy and had a 100% live birth rate
With mild male factor, 4 h coincubation increases fertilization rates and removes the need for rescue ICSI
Which overall conclusion about coincubation time and rescue ICSI is supported by the study?
With normal sperm, changing 4 h vs 16–18 h does not affect fertilization or pregnancy but can increase polyspermy; with mild male factor, 4 h lowers fertilization and combining 4 h with early rescue ICSI can avoid complete fertilization failure
Shortening coincubation to 4 h uniformly improves fertilization and pregnancy outcomes for all sperm qualities
Rescue ICSI eliminated polyspermy and had a 100% live birth rate
With mild male factor, 4 h coincubation increases fertilization rates and removes the need for rescue ICSI
Bekijk hier je kaarten, of sign up to study with spaced repetition.
What is sexual dimorphism as defined in the text?
Differences in gene sequences on the sex chromosomes only
Any differences between individuals of the same sex due to environment
Sex differences in morphology, physiology, and behavior arising from sexual differentiation mechanisms
Behavioral differences unrelated to reproductive function
In mammals with XX/XY systems, which genotype corresponds to genetic females?
XX
ZW
ZZ
XY
What role does SRY play in mammalian gonadal sex determination?
SRY on the Y chromosome drives testis development (testis-determining factor)
SRY controls dosage of DMRT1 to determine gonads
SRY determines phenotypic sex by producing Müllerian inhibiting substance directly
SRY causes ovary development on the X chromosome
In birds (ZZ/ZW), which gene and mechanism is described for gonadal sex determination?
SRY on the W chromosome determines testes
Dosage-dependent DMRT1 expression (higher in ZZ) promotes testes; lower expression promotes ovaries
Estrogen dosage on W determines male gonads
Dosage of AMH on Z controls ovarian development
According to the text, what hormonal combination leads to male internal genitalia in mammals?
Testes secrete estrogen which promotes Wolffian ducts
High DMRT1 and estrogen together cause male internal genitalia
Testes produce androgens plus MIS (Müllerian inhibiting substance), maintaining Wolffian ducts and causing Müllerian regression
Absence of androgens and presence of estrogen, maintaining Wolffian ducts
Which of the following is NOT one of the three fish sex-determination mechanisms listed?
Chromosomal systems (XX/XY or ZZ/ZW)
Flexible, hormone-dependent sex with exogenous hormone effects
Social dominance-based sex determination only
Polygenic or no clear sex chromosomes
Which environmental agents are named as endocrine disruptors that can modify sex determination?
Only heavy metals like lead and mercury
Viral infections during incubation
Environmental estrogen mimics (ethinyl estradiol, BPA, nonylphenol, some pesticides) and anti-androgens (fungicides, phthalates, herbicides)
Natural variation in temperature with no chemical influence
For temperature-dependent sex determination in reptiles and amphibians, when is the critical window for temperature influence?
Only during adult sexual maturation
Immediately before hatching only
Roughly the middle third of incubation after oviposition
The first day after oviposition only
Which taxa are given as examples where sex ratios vary with temperature during the middle-third period?
Lizards, alligators, most turtles, snapping turtles, and snakes
Mammals such as mice, rabbits, and primates
Most birds like chickens and pigeons
Amphibians such as frogs and salamanders only
What defines a protandrous sex change pattern in animals?
Individuals are genetically fixed as one sex and never change
Individuals mature first as females and later change to males; change driven by temperature
Individuals change sex multiple times daily based on light cycles
Individuals mature first as males and can later change to females; change driven by social/behavioral cues such as loss of a female
What triggers protogynous sex change according to the notes?
Exposure to excess androgens during embryogenesis
Seasonal day length changes only
Loss of the dominant male or shifts in social hierarchy
A prolonged drop in environmental temperature
What are the two principal functions of testes listed in the notes?
Gametogenic function producing motile sperm; endocrine function secreting inhibin, MIS, prostaglandins, androgens, and estrogens
Gametogenic function producing ova; endocrine function secreting progesterone and IGF1
Producing egg yolk and storing fertilized eggs
Only endocrine function with no gametogenesis; secreting thyroid hormones
What are the two principal functions of ovaries listed in the notes?
Gametogenic function producing ova; endocrine function secreting estrogens, androgens, progesterone, inhibin, oocyte maturation factors, and IGF1
Only gametogenic function producing sperm; no endocrine secretion
Storing and releasing urine into the cloaca
Endocrine function producing only corticosteroids; no gametogenesis
Which description matches the agnathan testis anatomy in the notes?
Paired testes with well-defined gonoducts and seminal vesicles
No testes present; gametes produced externally from skin glands
Most primitive; single testis extending the body cavity length, no gonoducts
Testes with multiple lobes and direct discharge to urinary bladder
What is the sperm path for chondrichthyes as stated in the notes?
Testis → coelomic cavity → genital funnel → urinary duct → cloaca
Testis → single undifferentiated duct → external pores separate from urinary tract
Testis → epididymis → ductus deferens → seminal vesicle/sperm sac → cloaca (with urine and digestive waste)
Testis → oviduct → uterus → cloaca
In teleost fishes, what is the path sperm follow from production to exit?
Testis → epididymis → urethra
Testes → seminal duct → cloaca
Paired testes → gonoducts → gonopore
Testes → coelom → urinary duct
How are urinary and reproductive exits arranged in teleost fishes compared with sharks and amphibians?
Teleosts have greater separation with separate exits for sperm, kidneys, and reproductive tract
Teleosts release sperm into the coelom which exits via the urinary duct
Teleosts share a single exit for urine and sperm through the cloaca
Teleosts use the Wolffian duct to carry both urine and sperm
In reptiles and birds, what does the Wolffian duct become and what is its role?
It becomes the oviduct carrying eggs to the cloaca
It becomes a urinary duct carrying both urine and sperm
It regresses and plays no role in adult reptiles and birds
It becomes the seminal duct (vas deferens) carrying only sperm to the cloaca, separating reproduction from urine
What is the typical sperm path in reptiles and birds from testis to exit?
Testis → epididymis → vas deferens (seminal duct) → cloaca
Testis → gonoducts → gonopore
Testis → urethra → urogenital opening
Testis → coelom → urinary duct → cloaca
Where is sperm primarily stored in reptiles versus birds?
Reptiles: epididymis. Birds: seminal sacs.
Reptiles: seminal sacs. Birds: epididymis
Reptiles: coelom. Birds: cloaca
Reptiles: vas deferens. Birds: oviduct
What is the sperm path in mammals from the testis to the urethra?
Testis → epididymis → cloaca
Testis → epididymis → vas (ductus) deferens → urethra
Testis → coelom → urinary duct
Testis → gonoducts → gonopore
Which statement correctly contrasts testicondid and scrotal mammals as given in the text?
Both testicondid and scrotal mammals always have a cloaca
Testicondid mammals keep testes internal; scrotal mammals have external testes in a scrotum to reduce temperature
Testicondid mammals have external testes; scrotal mammals keep testes internal
All mammals are scrotal; testicondid is not a real category
Which vertebrate group has mesonephric ducts modified as gonoducts (epididymis → ductus deferens)?
Amphibians
Chondrichthyes
Teleosts
Mammals
Which vertebrate group has dedicated gonoducts opening to a gonopore with separate exits for sperm, kidney, and gut?
Reptiles
Birds
Chondrichthyes
Teleosts
In which group does the ductus deferens carry both sperm and urine, with both feeding into the cloaca?
Teleosts
Chondrichthyes
Mammals
Amphibians
Which group is described as having a sperm-only seminal duct while urinary and digestive systems still join at the cloaca?
Birds
Mammals
Teleosts
Chondrichthyes
Which group uses epididymis → vas deferens → urethra and lacks a cloaca?
Mammals
Birds
Reptiles
Amphibians
Which group is internal and ectothermic, allowing the testes to remain inside the body?
Teleosts
Birds
Amphibians
Mammals
Which statement about gonoducts across vertebrates is correct?
Gonoducts first appear only in mammals
Gonoducts are absent in agnathans and present in later vertebrate groups
Gonoducts are absent in all vertebrates
Gonoducts are present in agnathans but lost in higher vertebrates
How does the separation of urinary and reproductive systems change over vertebrate evolution?
They become more separate over evolutionary time
They remain unchanged across all vertebrates
They become more combined over evolutionary time
They are separate only in fishes and recombine in tetrapods
Where are gonads typically located in ectothermic versus endothermic vertebrates?
Internal in ectotherms; moved nearer or to the body surface in endotherms as a cooling solution
External in ectotherms; internal in endotherms for insulation
Always external in both ectotherms and endotherms
Always internal in both ectotherms and endotherms
What is the functional reason many mammals have scrotal (external) testes?
To reduce temperature via vascular and molecular cooling mechanisms
To protect testes from predators
To reduce infection risk by exposure
To increase mating display visibility
What term describes species that retain internal testes rather than having scrotal testes?
Scrotal
Protandrous
Cloacal
Testicondid (internal testes)
What are the three classical phases of spermatogenesis?
Proliferative, Secretory, Degenerative
Oogonial, Cleavage, Implantation
Spermatogonial (mitotic), Spermiation, Fertilization
Spermatogonial (mitotic), Meiotic, Spermiogenesis
When does full, continuous spermatogenesis typically begin?
Around or after puberty when gonadotropins and sex steroids rise
Immediately at embryonic testis differentiation
At menopause
Only after first mating event
Which sequence correctly describes the HPG hormonal cascade regulating spermatogenesis?
GnRH → pituitary LH and FSH → LH to Leydig cells (androgens); FSH with androgens to Sertoli cells
Androgens → GnRH → FSH → Leydig cells
Pituitary directly produces androgens without LH or FSH
FSH → GnRH → LH → Sertoli cells only
What nuclear change occurs during spermiogenesis?
Nuclear envelope dissolves permanently
Nucleus enlarges and becomes transcriptionally active
Chromatin condenses dramatically so the nucleus becomes small and highly compact
Chromatin decondenses to allow increased gene expression
Which morphological changes are characteristic of spermiogenesis?
Development of cilia instead of flagellum and increased cytoplasmic volume
Formation of extra nuclei, retention of large cytoplasm, random mitochondrial distribution
Formation of multiple tails and dispersed mitochondria
Acrosome formation, flagellum elongation, cytoplasm mostly shed, mitochondria cluster in midpiece
Where is the major sperm storage and maturation site in mammals, birds, and reptiles?
Epididymis
Uterus
Seminal vesicle/sperm sac
Oviduct
In agnathans, what is the path of an ovulated ovum to the cloaca?
Ovulated ova → coelomic cavity → genital funnel → urinary duct → urogenital papilla → cloaca
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct → shell gland → cloaca
Ovulated ova → ovarian lumen → oviduct → uterus → cloaca
Which feature is a similarity between male and female agnathans?
Both use an external oviduct (Müllerian duct) for gamete passage
Both sexes have paired gonads located in the pelvic region
Both have separate dedicated gonoducts connecting gonads directly to cloaca
Both have a single gonad extending along the body cavity and use the coelomic cavity → genital funnel → urinary duct → cloaca for gamete release
What is a typical difference between oviparous and viviparous chondrichthyan ovaries?
Oviparous species usually have one ovary, whereas viviparous species have two functional ovaries
Viviparous species lack ovaries and develop eggs in the liver
Both oviparous and viviparous species always have two ovaries
Oviparous species usually have two ovaries, whereas viviparous species usually have one (right) ovary
In chondrichthyans, through which sequence does an ovulated egg pass before reaching the cloaca?
Ovulated ova → ovarian cavity → ovarian duct → gonopore → cloaca
Ovulated ova → coelomic cavity → ostia → oviduct (Müllerian duct) → shell gland → uterus (if viviparous) → cloaca
Ovulated ova → coelomic cavity → infundibulum → oviduct → vagina → cloaca
Ovulated ova → coelomic cavity → genital funnel → urinary duct → cloaca
How do teleost ovaries typically release eggs compared with sharks?
Teleosts use a true Müllerian duct system like sharks
Teleost eggs are retained in a uterus until hatching
Teleost eggs are released into the coelomic cavity then pass through ostia to a Müllerian oviduct
Teleost eggs are released into the ovarian lumen (not the coelom) and pass via an ovarian duct to the outside
Which oviduct region in birds and reptiles is primarily responsible for albumen (egg white) secretion?
Isthmus
Infundibulum
Magnum
Uterus
What is the normal path of an ovulated mammalian ovum from ovulation to exit?
Coelomic cavity → uterus → fallopian tube → cervix → vagina
Ovarian lumen → infundibulum → uterus → vagina → cervix
Coelomic cavity → infundibulum with fimbriae → fallopian tube → uterus → cervix → vagina
Infundibulum → coelomic cavity → fallopian tube → uterus → vagina
Which uterine type has two completely separate horns and two cervices, often associated with large litters?
Simplex
Bicornuate
Bipartite
Duplex
Which uterine form has no horns, a single uterine cavity, one cervix, and is associated with centralized implantation and single offspring?
Bipartite
Simplex
Duplex
Bicornuate
Into where do teleost fishes typically ovulate?
Infundibulum with fimbriae
Oviduct derived from Müllerian duct
Coelomic cavity
Ovarian lumen
Which structure gives rise to oviducts (shell gland, uterus, etc.) in reptiles, birds, and mammals?
Coelomic epithelium
Müllerian ducts
Ovarian lumen/gonoduct
Wolffian ducts
How many functional ovaries do most adult birds and most mammals have, respectively?
Birds: one (right); Mammals: one
Birds: one (typically left); Mammals: two
Birds: two; Mammals: one
Birds: paired masses of follicles; Mammals: paired in some, single in others
Which new characteristic is listed for amniotes regarding eggs and oviduct specialization?
Amniotic egg with four extraembryonic membranes and regional oviduct specialization
Single functional ovary and loss of fimbriae
Ovarian lumen ovulation and absence of Müllerian ducts
Placenta replaces albumen and no oviduct regions
What new reproductive characteristic is specified for mammals compared to other amniotes?
Amniotic egg with four membranes
Ovarian duct replaces Müllerian duct
Placenta replaces shell/albumen and uterus specialized for implantation
Ovulation into ovarian lumen
When does spermatogenesis begin in human males?
Begins during embryonic development and pauses until puberty
Is completed before birth and remains inactive until puberty
Starts only after first ejaculation in adulthood
Around puberty and continues throughout reproductive life
Which statement correctly describes the female oocyte pool timing and numbers?
Massive oocyte pool forms embryonically (~3 million per ovary → ~1 million at birth → ~250,000 at puberty)
Oocyte pool forms at puberty and reaches ~3 million per ovary then declines
Oocytes are produced continuously after puberty increasing numbers over time
No oocytes are present at birth; all develop after puberty
When does meiosis I of oocytes occur and complete in human females?
Begins and completes entirely after fertilization
Begins at puberty and completes only after menopause
Begins during embryonic development and completes before birth
Begins during embryonic development, pauses, and is completed just before ovulation
Which event triggers completion of meiosis II in the human oocyte?
Ovulation alone
Fertilization
Attachment to the uterine wall
LH surge without fertilization
What is the primary endocrine role of the pituitary in folliculogenesis?
Secretion of progesterone from the corpus luteum
Production of androgens by theca cells
Direct conversion of androgens to estrogens within follicles
Release of LH and FSH in response to hypothalamic GnRH pulses
Which function is attributed to theca cells during follicle development?
Nourish the oocyte and produce estrogen directly
Provide structural support and produce androgens for granulosa conversion
Trigger GnRH release from the hypothalamus
Form the corpus luteum after ovulation and secrete progesterone
Which roles do granulosa cells perform in the ovarian follicle?
Produce androgens as the primary endocrine product
Nourish the oocyte, produce estrogens and factors, and later contribute to corpus luteum
Act only as passive structural cells with no hormonal role
Secrete GnRH to stimulate the pituitary
What is the main endocrine function of the corpus luteum after ovulation?
Secrete progesterone to prepare the uterus for implantation and inhibit GnRH
Secrete FSH and LH to promote new follicular waves
Convert progesterone into estrogens to trigger ovulation
Produce androgens to stimulate follicle growth
Which two key timing contrasts differentiate male and female gametogenesis?
Male starts embryonically and pauses until puberty; female starts at puberty and continues continuously
Male oocyte number is fixed early; female sperm production is continuous
Both male and female gametogenesis start at puberty and proceed continuously
Male starts at puberty and is continuous; female starts embryonically and oocyte number is fixed early and declines
What immediately triggers the oocyte to complete meiosis I and be released during ovulation?
LH surge
Progesterone peak
FSH surge
GnRH surge
When does meiosis I and meiosis II occur in oogenesis?
Both meioses are completed at sexual maturity regardless of fertilization
Meiosis I completes at fertilization; meiosis II completes at ovulation
Meiosis I and II both complete before birth
Meiosis I begins embryonically and completes just before ovulation; meiosis II completes only if fertilization occurs
What primarily drives the onset of ovarian cycles at sexual maturity?
Sustained high estrogen secretion from ovaries
Increase in pulsatile GnRH production and secretion from the hypothalamus
Continuous LH elevation from the pituitary
Persistent photoperiod/seasonal cues alone
How are ovarian cycles subsequently regulated after onset?
Only estrogens regulate the cycle without LH or FSH involvement
GnRH stimulates pituitary LH and FSH; ovarian estrogens, progesterone, and androgens feedback on hypothalamus/pituitary
Ovarian cycles run independently of hypothalamic or pituitary hormones
Pituitary hormones inhibit GnRH and stop ovarian hormone production
Which statement best describes sexual receptivity differences between estrus and menstrual cycles?
In estrus cycles receptivity is continuous; in menstrual cycles receptivity occurs only at ovulation
Both estrus and menstrual cycles have receptivity only during a brief heat period
In estrus cycles receptivity is restricted to estrus coinciding with ovulation; in menstrual cycles receptivity is essentially continuous
Neither cycle type shows any hormonal influence on receptivity
What is a distinguishing feature of menstrual cycles not present in broad estrus cycles?
Sexual receptivity restricted to a brief heat period
Endometrial sloughing (menses) if no pregnancy
No involvement of estrogen or progesterone
Ovulation does not occur
Which hormone stimulates endometrial growth during the proliferative phase?
Progesterone from corpus luteum
Estrogen from developing follicles
Prostaglandins from endometrium
FSH from pituitary
What is the primary endometrial effect of progesterone in the secretory phase?
Causes ischemic necrosis of the functional layer
Increases prostaglandin production leading to contractions
Converts endometrium to glandular, secretory tissue suitable for implantation
Stimulates endometrial proliferation and progesterone receptor expression
What sequence leads to menstrual phase when there is no pregnancy?
Estrogen rise → progesterone rise → increased vascularization
Corpus luteum persists → high estrogen and progesterone → menstruation
Corpus luteum regression → estrogen and progesterone drop → prostaglandins increase
Prostaglandin decrease → vasodilation → shedding
How do prostaglandins contribute to menstrual bleeding?
They stimulate progesterone production to maintain the endometrium
They directly dissolve endometrial glands without affecting blood flow
They cause vasoconstriction of endometrial vessels leading to ischemic necrosis of the functional layer
They inhibit myometrial contractions preventing tissue expulsion
What is the main cause of primary dysmenorrhea?
Structural obstruction by pelvic adhesions
Ectopic endometrial tissue outside the uterus
Benign smooth muscle tumors of the uterus
Excess prostaglandin production in the endometrium causing excessive uterine contractions
Which treatment is recommended for primary dysmenorrhea in the text?
Antibiotics to reduce pelvic infection
Progesterone receptor blockers
Surgical removal of uterine fibroids
NSAIDs that block prostaglandin production
Which conditions are cited as causes of secondary dysmenorrhea?
Ectopic pregnancy and choriocarcinoma
Primary excess prostaglandins only
Ovarian failure and menopause
Endometriosis and uterine fibroids
According to the lecture hypothesis, how did concealed ovulation and continuous receptivity affect human social evolution?
They increased male detection of fertile periods, reducing pair bonding
They caused frequent large-scale migrations of human groups
They kept males close to mates, promoting long-term pair bonds and more permanent social groupings
They eliminated the need for cooperative hunting
Which statement best describes external fertilization in vertebrates?
Sperm are deposited directly into the female reproductive tract
Gametes are retained and fertilized within a nest or burrow exclusively
Gametes are released directly into water, as in many bony fishes and amphibians
Fertilization occurs inside a protective egg membrane within the female
What are two main problems associated with external fertilization listed in the notes?
Delayed ovulation and cryptic female choice
Sperm competition within the female tract and need for copulatory organs
Requirement for internal membranes and placental transfer
Gametes disperse before fertilization and osmoregulatory stress from environment
Which solution is described for reducing gamete dispersal during external fertilization?
Group spawning or synchronized release to keep gametes concentrated
Using copulatory organs to deposit sperm in the female tract
Storing sperm in the epididymis for months
Temperature-dependent sex determination to time mating
How do vitelline layers help external eggs according to the notes?
They enclose eggs in protective membranes that resist osmotic change
They store sperm for later fertilization
They actively pump salts to equalize internal and external osmolarity
They function as copulatory organs for sperm transfer
Which feature characterizes internal fertilization as listed in the notes?
Sperm are deposited directly in the female tract, occurring in reptiles, birds, mammals
Gametes are released into the water and fertilize externally
Eggs are always enclosed in vitelline layers before fertilization
Fertilization requires synchronized group spawning
What solution is noted for ensuring sperm reach eggs in internal fertilization?
Enclosing eggs in vitelline layers to resist osmotic change
Synchronized external release of gametes
Storing sperm in female oviductal sites only
Use of copulatory organs and specialized ducts for direct transfer
Which is a listed advantage of sperm storage?
Prevents any possibility of sperm competition
Allows separation of mating from fertilization in time
Removes requirement for specialized anatomical adaptations
Eliminates need for ovulation entirely
Which disadvantage of sperm storage is mentioned in the notes?
Always causes immediate fertilization upon storage
Prevents females from controlling paternity
Requires specialized anatomical and physiological adaptations to maintain sperm viability
Removes the need for seasonal breeding timing
Which example of sperm storage location is explicitly given in the notes?
All females store sperm in ovaries only
Sperm are stored in external nests until fertilization
Sperm are stored exclusively in the vitelline layer
Some males store sperm within the epididymis
Where does sperm capacitation occur in mammals?
Testes seminiferous tubules
Male epididymis
Vagina only
Female reproductive tract (uterus and oviduct)
Which change is a key outcome of capacitation that readies sperm for fertilization?
Formation of the zona pellucida
Hyperactivated motility and increased acrosome readiness
Fusion of pronuclei
Completion of sperm meiosis
Which molecular sequence during capacitation leads to increased sperm Ca2+ sensitivity?
Cholesterol addition to membrane → decreased motility
Exposure to Ca2+ and HCO3¯ → increased cAMP → phosphorylation cascades
Removal of Ca2+ and HCO3¯ → decreased cAMP → phosphorylation cascades
Direct progesterone binding to DNA → transcriptional changes
What triggers the acrosome reaction after capacitation?
Fusion of pronuclei
Completion of the egg's second meiotic division
Sperm binding to zona pellucida glycoproteins such as ZP2 and ZP3
Progesterone binding to egg plasma membrane receptors
How do differences in acrosome structure across species affect fertilization strategy?
Acrosome shape only affects sperm motility, not penetration strategy
All species use identical enzymatic strategies regardless of acrosome shape
Species with a fibrous core rely more on mechanical penetration; species without it rely more on enzymes
Species with a fibrous core cannot undergo the acrosome reaction
What is a key difference between mammalian and avian fertilization regarding sperm entry?
Mammals require multiple sperm nuclei to form the zygote
Mammals typically prevent multiple sperm fusion; birds allow physiological polyspermy but restrict multiple sperm nuclei from participating
Birds prevent any sperm from entering the egg cytoplasm
Birds fuse all entering sperm nuclei to form a polyploid zygote
Which reproductive mode is characterized by laying yolk-filled eggs into the external environment with yolk synthesized in the liver during vitellogenesis?
Parthenogenetic
Ovoviviparous
Viviparous
Oviparous
Which developmental provisioning mode retains eggs within the uterus, with embryos primarily nourished by yolk but sometimes supplemented by uterine secretions or a quasi-placenta?
Aplacental
Viviparous
Oviparous
Ovoviviparous
Which reproductive mode involves internal development with maternal nutrient supply via a true placenta where fetal and maternal circulations meet in a common capillary bed?
Viviparous
Ovoviviparous
Oviparous
Ovo-viviparous
In the classic amniotic egg, which extraembryonic membrane directly encases and cushions the embryo and prevents desiccation?
Yolk sac
Allantois
Chorion
Amnion
Which extraembryonic membrane in the classic amniotic egg stores metabolic wastes like uric acid and also participates in gas exchange?
Allantois
Yolk sac
Chorion
Amnion
In eutherian (placental) mammals, what does the chorion represent?
The umbilical cord and placental vessels
The fetal portion of the placenta
The yolk-containing nutrition sac
A fluid-filled cavity that cushions the embryo
Which of the following is NOT one of the three main types of changes during embryonic development listed in the notes?
Morphogenesis
Growth
Apoptosis
Differentiation
Which developmental process involves cells becoming specialized for different functions such as muscle, neuron, or epithelium?
Morphogenesis
Growth
Differentiation
Fertilization
What is the defining characteristic of cleavage after fertilization in vertebrates?
Immediate formation of differentiated tissues without a blastula stage
Fusion of cells to form a syncytium rather than separate blastomeres
Slow cell divisions with substantial embryo growth before cell number increases
Rapid cell divisions with little or no overall growth, producing a blastula
How does yolk distribution between the animal and vegetal poles affect cleavage?
Yolk distribution has no effect on cleavage speed or cell number
More yolk at the vegetal pole causes slower or incomplete divisions there and more cells at the animal pole
Even yolk distribution leads to incomplete divisions only at the animal pole
More yolk at the animal pole causes faster divisions at the vegetal pole
What consequence does the animal-vegetal polarity help establish during early development?
Immediate organogenesis without gastrulation
Complete symmetry with no axis formation
Body axes and influence on later gastrulation movements
Formation of extraembryonic membranes only
In the Dai et al. coincubation study, how did short (4 h) versus standard (16–18 h) sperm-oocyte coincubation affect fertilization with normal sperm?
Fertilization, embryo quality, clinical pregnancy, and implantation rates were similar for short and standard coincubation
Short coincubation eliminated implantation despite similar fertilization
Short coincubation greatly increased fertilization rates compared with standard
Standard coincubation caused significantly worse embryo quality with normal sperm
How did short (4 h) coincubation affect fertilization rates when a mild male factor was present in the Dai et al. study?
Short coincubation had no impact on fertilization rate with mild male factor
Short coincubation improved embryo quality but lowered pregnancy rates
Short coincubation increased fertilization rate to above 80%
Short coincubation significantly reduced fertilization rate (62.6%) versus standard (68.7%)
What is 'rescue ICSI' as described in the notes?
Performing ICSI on oocytes that failed to show signs of fertilization after initial IVF insemination
A method of fertilizing eggs using donor sperm after failed IVF
A technique to rescue damaged sperm before insemination
Using ICSI before any IVF insemination to prevent fertilization failure
What is the primary purpose of performing rescue ICSI when no second polar body is seen at 4–6 h?
To increase implantation rates for all IVF patients regardless of sperm quality
To prevent complete fertilization failure in IVF cycles, especially when sperm parameters are poor (mild male factor)
To replace embryo transfer with earlier cryopreservation
To reduce polyspermy in cycles with normal sperm parameters
What fertilization rate was reported after rescue ICSI in the study?
62.6%
68.7%
71.3%
34.7%
Which polyspermy rate was observed after rescue ICSI in the study?
24.1%
7.3%
4.1%
3.2%
In cycles with normal sperm (Group I), how did 4 h coincubation compare with 16–18 h for polyspermy?
Polyspermy was eliminated with 4 h coincubation
Polyspermy rate was significantly higher with 4 h (7.3%) than with 16–18 h (4.1%)
Polyspermy rate was significantly lower with 4 h than with 16–18 h
There was no significant difference in polyspermy between 4 h and 16–18 h
In cycles with mild male factor (Group II), what effect did shortening coincubation to 4 h have on fertilization rate?
Fertilization rate was significantly higher with 4 h than with 16–18 h
4 h coincubation improved clinical pregnancy rates compared with 16–18 h
There was no significant difference in fertilization rate between 4 h and 16–18 h
Fertilization rate was significantly lower with 4 h (62.6%) than with 16–18 h (68.7%)
Which overall conclusion about coincubation time and rescue ICSI is supported by the study?
With normal sperm, changing 4 h vs 16–18 h does not affect fertilization or pregnancy but can increase polyspermy; with mild male factor, 4 h lowers fertilization and combining 4 h with early rescue ICSI can avoid complete fertilization failure
Shortening coincubation to 4 h uniformly improves fertilization and pregnancy outcomes for all sperm qualities
Rescue ICSI eliminated polyspermy and had a 100% live birth rate
With mild male factor, 4 h coincubation increases fertilization rates and removes the need for rescue ICSI
| Taxon | Gonoducts & sperm path | Urinary vs reproductive separation | Testis location (adaptive note) |
|---|---|---|---|
| Agnathans | No gonoducts; gametes enter coelom → genital funnel → urinary duct → cloaca | None; shared pathways | Internal; ectothermic so internal testes are fine |
| Chondrichthyes | Mesonephric ducts modified to carry sperm → cloaca | Partial separation; cloaca shared | Internal; ectotherms |
| Teleosts | Dedicated gonoducts to gonopore | High separation; distinct exits | Internal; ovulation into ovarian lumen |
| Amphibians | Ductus deferens carries sperm and urine → cloaca | Limited separation at duct level | Internal; ectotherms |
| Reptiles & Birds | Wolffian duct → seminal duct to cloaca; sperm storage common | Reproductive and urinary separated at ducts; cloaca still common exit | Internal; birds often position testes near air sacs to aid cooling |
| Mammals | Epididymis → vas deferens → urethra (no cloaca) | Strong separation; distinct outlets | Many are scrotal (external cooling) but some testicondid species have internal testes |
Weet je zeker dat je de volgende 0 flashcard(s) wilt verwijderen? Dit kun je niet ongedaan maken.
Kies tags om te verwijderen uit 0 geselecteerde flashcard(s):
Tags laden...