In which phase of estrous cycle is progesterone secreted?
Diestrous phase
Key Terms
In which phase of estrous cycle is progesterone secreted?
Diestrous phase
What is the quiescent stage between two estrous cycles called?
Anestrum
Does bleeding occur in estrous phase?
No
What is the seasonal testicular acitivity in males of some species called?
Rut cycle
What constitutes the egg in animals?
Oocyte+ egg membrane
How many types of egg membrane can an egg (of animals) have?
Primary egg membrane
Secondary egg membrane
Tertiary egg membrane
Related Flashcard Decks
Study Tips
- Press F to enter focus mode for distraction-free studying
- Review cards regularly to improve retention
- Try to recall the answer before flipping the card
- Share this deck with friends to study together
| Term | Definition |
|---|---|
In which phase of estrous cycle is progesterone secreted? | Diestrous phase |
What is the quiescent stage between two estrous cycles called? | Anestrum |
Does bleeding occur in estrous phase? | No |
What is the seasonal testicular acitivity in males of some species called? | Rut cycle |
What constitutes the egg in animals? | Oocyte+ egg membrane |
How many types of egg membrane can an egg (of animals) have? | Primary egg membrane Secondary egg membrane Tertiary egg membrane |
What secreted the primary egg membrane around the egg in animals? | Oocyte/ovum |
What is the primary egg membrane in humans? | Zona pellucida |
What is the primary egg membrane of frogs? | Vitelline membrane |
What secretes the secondary egg membrane of animal eggs? | Ovary |
What is the secondary egg membrane of human eggs called? | Corona radiata |
What is the tertiary egg membrane of animal eggs secreted by? | Oviduct/uterus |
What is the tertiary egg membrane of frog's egg called? | Jelly coat |
Which type of egg is a human egg on the bases of amount of yolk? | Alecithal |
What type eggs do marsupials have on the basis of amount of yolk? | Microlecithal |
What type of eggs do amphibians have on the basis of amount of yolk? | Mesolecithal |
What type of eggs do reptiles and birds have on the basis of amount of yolk? | Megalecithal |
What are isolecithal eggs? | The very little amount of yolk present is uniformly distributed throughout the ooplasm |
In what type of eggs is isolecithal condition observed? | Alecithal and microlecithal eggs |
What type of eggs do insects have on the basis of amount of yolk? | Megalecithal |
What type eggs have heterolecithal distribution of yolk? | Mesolecithal and megalecithal eggs |
What type of eggs are found in amphibians on the basis of distribution of yolk? | Telolecithal |
What type of eggs are found in reptiles and birds on the basis of distribution of yolk? | Discoidal |
What type of eggs are found in prototherians on the basis of amount of yolk? | Megalecithal |
What type of eggs are found in prototherians on the basis of distribution of yolk in eggs? | Discoidal |
What type of eggs are found in insects on the basis of distribution of yolk in eggs? | Centrolecithal |
What are eggs which have shells called? | Cleidoic eggs |
Which is the largest cell of human body? | Egg |
What is germinal vesicle? | The enlarged nucleus of egg of humans |
What do the cortical granules of human egg contain? | Hydrolytic enzymes and mucopolysaccharides |
Which is the animal pole of human egg? | Part of egg from where polar body extrudes out |
Perivitelline space in egg is present between | Zona pellucida and oocyte |
What is the ground substance of corona radiata? | Hyaluronic acid |
How long does the human sperm's viability last? | 24 to 48 hours |
How long does the human egg's viability last? | 48 to 72 hours |
How long does capacitation of sperm take? | 6 to 7 hours |
How does the destabilization of plasma membrane of sperm take place? | By rearrangement of glycoproteins and dissolution of cholesterol |
What is the speed of a hypermotile sperm? | 4 to 5 mm/min |
What type of movement does the flagella of a hypermotile sperm perform? | Whiplash movement |
Which chemical propels sperm towards uterine cavity? | Prostaglandins |
Which is the acidic protein present on sperm's membrane- anti fertilin or fertilin? | Antifertilin |
Which is the glycoprotein on egg's surface- antifertilin or fertilin? | Fertilin |
When does acrosome reaction occur? | When sperm binds to ZP3 receptor on zona pellucida |
What causes the exocytosis of sperm lysins from acrosome in acrosomal reaction? | Calcium |
Which enzymes dissolves hyaluronic acid? | Hyaluronidase enzyme |
Which enzyme digests corona radiata of egg? | Corona pentrating enzyme |
Which enzyme digests zona pellucida of egg? | Acrosin/ zonalysin |
How does fast block to polyspermy occur in egg? | By opening of Na+ channels leading to rapid depolarisation of oolema |
What causes the exocytosis of cortical granules from eggs into perivitelline space? | Calcium ions |
How thick is the fertilization membrane? | 900 Å |
What leads to slow block to polyspermy in human egg? | Cortical and zona reaction |
Zona reaction happens in human egg due to? | Absorption of water |
Which part of sperm enters the the zona pellucida of egg during fertilization? | Whole sperm enters but middle piece and tail degenrates |
How does sperm make it possible for meiosis II of secondary oocyte to be completed? | Sperm destroys metaphase promoting factor (MPF) of egg and turns on anaphase promoting factor (APF) |
What happens in amphimixis step of syngamy of sperm and egg? | Chromosomal membrane dissolves and chromosome of sperm and egg mix |
What is embryology? | Study of first eight weeks of pregnancy after fertilisation |
How long does the first cleavage in zygote in humans take? | 30 hours |
How long does the second cleavage in zygote in humans take after fertilization? | 40 hours |
What are the phases of interphase in cleavage of zygote in humans? | Only S-phase, G1 and G2 phase are absent |
What is nucleocytoplasmic ratio? | It is a ratio of the size of the nucleus of a cell to the size of the cytoplasm of that cell. (N:C) |
When does the third cleavage take place in human zygote after fertilisation? | 72 hours |
What type of cleavage is the first cleavage in human zygote? | Meridional |
What type of cleavage is the second cleavage in human zygote? | Meridional at right angle to the first cleavage |
What type of cleavage is the third cleavage in human zygote? | Equatorial |
What kind of cleavage do humans show? | Holoblastic rotational and indeterminate cleavage |
What is indeterminate cleavage? | Fate of blastomeres is decided after 8-celled stage (morula) |
On which axis does the meridional cleavage take place? | On the longitudinal axis from animal pole to vegetal pole |
Holoblastic cleavage takes place in which type of eggs (on the basis of amount of yolk)? | Alecithal, microlecithal, mesolecithal |
Meroblastic cleavage takes place in which type of eggs (on the basis of amount of yolk)? | Megalecithal |
Discoidal meroblastic cleavage is found in which animals? | Birds, reptiles |
Superficial meroblastic cleavage is found in which animals? | Insects |
What is bilateral cleavage of zygote? | Only meridional cleavage takes place |
What type ofcleavage occurs in cephalopods? | Bilateral cleavage |
WHat type of cleavage occurs in protostomes? | Spiral cleavage |
What type of cleavage occurs in deuterostomes? | Radial cleavage |
What makes rotational cleavage different from other types of cleavage? | It has a transient 3-celled stage |
Where is the morula present? | Fallopian tube |
What is the difference between the zona pellucida of morula and blastocyst? | Morula-Zona pellucida intact | Blastocyst- zona pellucida ruptures during maturation |
At which cell stage does uterine milk seep into blastocyst? | 32 cell stage |
How does the blastocoel form in blastocyst? | By seeping in of uterine milk |
At which cell stage does the blastocyst hatch? | 64 to 128 |
Why does the zona pellucida rupture in blastocyst? | Due to trophoblastic enzymes |
How many days from fertilization does it take for implantation of blastocyst? | 7 days |
Which layer of embryo prevents immature implantation of embryo? What can its immature rupturing cause | Zona pellucida | Ectopic pregnancy |
Name the layers the trophoblast of blastocyst is divided into. | Cytotrophoblast | Syncitiotrophoblast |
WHat is cytotrophobast of blastocyst? | Inner cellular layer of trophoblast |
What is syncytiotrophoblast of blastocyst? | Outer multinucleated layer |
What do the chorionic villi of blastocyst connect with to form placenta? | Decidual crypts |
Which layer of blastocyst secretes human chorionic gonadotrophin? | Trophoblast |
What is the role of hCG in pregnancy? | Acts like LH and maintains corpus luteum for first trimester of pregnancy |
Which hormone is known as pregnancy hormone | Progesterone |
What is coeloblastula? | Hollow blastula |
What is stereoblastula? | Solid blastula |
What does the hypoblast layer of blastocyst form? | Embryonic endoderm |
Which layers of blastula form the chorion? | Cytotrophoblast + extra embryonic mesoderm |
What form amnion in blastula? | Extraembryonic mesoderm +epiblast/ectoderm |
What prevents human embryo from desiccation? | Amnion |
What form yolk sac in human embryo? | Extra-embryonic mesoderm + endoderm/hypoblast |
What is the function of yolk sac in humans? | Haemopoietic | Forms male and female germ cells |
What form alantois? | Extra-embryonic mesoderm + endoderm (hypoblast) |