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84 Cards in this Set
- Front
- Back
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what is embryology?
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the study of how embryos develop
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what is teratology?
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the study of abnormal embryo development
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what is gametogenesis?
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the making of sperm and egg
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what is the term for the making of sperm and egg?
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gametogenesis
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where do primordial germ cells migrate from?
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yolk sac
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where do primordial germ cells migrate to?
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genital ride
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what will primordial germ cells develop into?
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eggs or sperm
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what will the genital ridge develop into?
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testis or ovary
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what happens to primordial germ cells in males?
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dormant until sexual maturity
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what happens to primordial germ cells in females?
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divide to form oogonia
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where does spermatogenesis occur?
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in the seminiferous tubules of the testis
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what occurs in the seminiferous tubules of the testis?
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spermatogenesis
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what is the sequence of cells that occur in spermatogenesis?
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spermatogonium, primary spermatocytes, secondary spermatocytes, spermatids, spermatozoan
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in spermatogenesis, where does meiosis 1 occur?
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between spermatogonium to primary spermatocytes
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in spermatogenesis, where does meiosis 2 occur?
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between primary spermatocytes to spermatids
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How many chromosomes does a spermatid have?
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1/2n
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how many chromosomes does a spermatozoan have?
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1/2n
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how many chromosomes does a spermatogonium have?
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1n
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how many chromosomes does a primary spermatocytes have?
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1n
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how many chromosomes does a secondary spermatocytes have?
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1n
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how much DNA does a spermatozoan have?
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1/2
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how much DNA does a spermatid have?
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1/2
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how much DNA does a spermatogonium have?
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whole
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how much DNA does a primary spermatocytes have?
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whole
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how much DNA does a secondary spermatocytes have?
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whole
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what do spermatogonium becomes?
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primary spermatocytes
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what do primary spermatocytes becomes?
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secondary spermatocytes
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what do secondary spermatocytes becomes?
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spermatids
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what do spermatids becomes?
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spermatozoan
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what do spermatozoans derive from?
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spermatids
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what do spermatids derive from?
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secondary spermatocytes
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what do secondary spermatocytes derive from?
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primary spermatocytes
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what do primary spermatocytes derive from?
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spermatogonium
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what is spermiogenesis?
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transformation of spermatid to spermatozoan
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what is the transformation of spermatozoan to spermatid called?
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spermiogenesis
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what occurs during spermiogenesis?
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loss of cytoplasm, formation of acrosome, condensation of nucleus, and formation of head, midpiece, and tail
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what is the sequence of cells that occur in oogenesis?
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primordial germ cell, oogonium, primary oocytes, secondary oocyte, single mature oocyte
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in oogenesis, where does meiosis 1 occur?
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between primary oocyte and secondary oocyte
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in oogenesis, where does meiosis 2 occur?
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between secondary oocyte and mature oocyte
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what do oogonium become?
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primary oocytes
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what do primary oocytes becomes?
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secondary oocytes
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what do secondary oocytes becomes?
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mature oocyte
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what do mature oocyte derive from?
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secondary oocyte
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what do secondary oocyte derive from?
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primary oocyte
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what do primary oocyte derive from?
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oogonium
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what do primordial germ cells becomes?
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spermatogonium and oogonium
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what does PGC stand for?
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primordial germ cell
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what happens to most oogonium?
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degenerate
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what happens to primary oocytes?
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remain dormant until sexual maturity while in prophase of first meiotic division
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in terms of cells, between what cells do dogs ovulate/fertilization occur?
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primary oocyte and secondary oocyte
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in terms of cells, between what cells do horses ovulate/fertilization occur?
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primary oocyte and secondary oocyte
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in terms of cells, between what cells do most species ovulate/fertilization occur?
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secondary oocyte and mature oocyte
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how many oocytes result from meiosis?
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1 + 3 polar bodies
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how many spermatids result from meiosis?
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4
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what structures develop around the mature oocyte?
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the zona pellucida and corona radiata
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what is the zona pellucida?
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glycoprotein layer surrounding the oocyte
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what is the corona radiata?
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follicular cells surrounding the zona pellucida
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what are the steps to fertilization?
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capacitation of spermatid if female tract, penetration of the corona radiata (phase 1), acrosome reaction, penetration of the zona pellucida (phase 2), inner acrosomal membrane dissolves, secondary oocyte in second meiotic division, penetration oocyte membrane (phase 3), fusion oocyte and sperm cell membranes
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what are the prerequisites to fertilization?
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phase 1 penetrate corona radiata, phase 2 penetrate zona pellucida, phase 3 penetrate oocyte membrane
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what is capacitation?
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protein loss in sperm plasma membrane enabling increased motility, occurs in female reproductive tract
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what is the acrosome reaction?
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release of hyaluronidase to erode the corona radiata and acrosin to erode the zona pellucida
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what happens at zona pellucida receptors?
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membranes of spermatid and oocyte fuse and sperm tail degenerates
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what does ZP stand for?
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zona pellucida
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what does CR stand for?
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corona radiata
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what does the suffix -ase mean?
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enzyme that degrades
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what are the responses of oocyte to fertilization?
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cortical reaction, zona reaction, union of pronuclei, zygote formed, metabolic activation
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what occurs in the cortical reaction?
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vesicles form under the oocyte's plasma membrane
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what occurs in the zona reaction?
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vesicles release proteases, ZP solubility changes, ZP receptors inactivated, creates a block to polyspermy
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when is sex determined?
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when the zygote forms
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what is a zygote?
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single cell after union of pronuclei
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what is metabolic activation?
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cellular/molecular events of embryogenesis begin
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how does in vitro fertilization occur?
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obtain progeny from valuable cows that are infertile, flush oocytes from ovaries or oviducts, co-culture oocytes with capacitated sperm at body temp and with oviduct cells for a few days (viability), then transferred into uterus of recipient cow
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what occurs during preimplantation development?
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zygote becomes morula becomes blastocyst becomes blastula
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what occurs during cleavage stages?
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rapid mitotic division resulting in less volume in cells, but same total volume
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what are the cleavage stages?
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two cell stage, four cell stage, morula
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what develops at the morula stage?
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inner and outer cell mass
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what developes at the embryoblast stage?
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a trophoblast and fluid filled blastocele developes, then embryonic disk developes
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what developes at the blastula stage?
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after hatching, the blastocele forms
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what does hatching mean?
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embryo is released from zona pallucida which allows implantation
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what are the species variation in blastula
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ovoid, spherical, worm like, etc
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what structures exist in the blastula?
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hypoblast, trophoblast, epiblast, embryonic disc
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what occurs in gastrulation?
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a primitive node developes at the embryonic disc, expanding into a primitive streak, enabling invaginating mesoderm cells between the epiblast and hypoblast
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what are the primary germ layers?
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ectoderm (nerve, skin), mesoderm (muscles and organs), endoderm (digestive tract)
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what do the primary germ layers do?
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give rise to all tissue necessary for life
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