reproduction
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (24 张)
What are the divisions in spermatogenesis? How many N at each stage?
PGC -2N spermatogonia A -2N spermatogonia B -2N primary spermatocyte - 2N secondary spermatocyte -N round spermatid -N elongated spermatid - N spermatazoa -N
When does spermatogenesis occur in males? Which life stage?
post puberty.
What are the divisions in oogenesis? How many N at each stage? When do these occur in a female? Life stages? When are polar bodies excluded?
PGC -2n oogonia - 2n primary oocyte -2n - pre birth - pro I secondary oocyte -n - polar body - metII until ovulation. mature oocyte -n -polar body.
What is external fertilisation and what living things do this? What is a good example of external fertilisation?
outside of the body - aquatic animals - fish.
What is internal fertilisation and what living things do this?
.sperm deposited directly inside usually female - nearly all mammals.
What is urchin reproductive strategy similar to? Why is it so easy to study them?
most mammals - they can be stimulated in lab to produce eggs and sperm easily.
Draw a sea urchin sperm and label
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Draw a sea urchin oocyte and label
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What happens when the sperm meets the oocyte?
• penetrates cumulus. • binds to zona pellucida receptors causing acrosome reaction. • penetrates zona pellucida and fuses with oocyte. leads to cortical reaction - bona hardening.
What is the function of the acrosome?
contains enzymes used to digest through cumulus and zona pellucida/vitelline layer.
What is the acrosomal process made from? And what is its role?
contains enzymes used to digest through cumulus and zona pellucida/vitelline layer.
How do they avoid polyspermy? What are the problems with polyspermy?
• fast block = electrochemical block via influx of Na - temporary an d for externals only. • urchin - secretion of a barrier of cortical granules
What is the role of the oocytes cortical granules?
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How is the fertilisation envelope formed? What does it do?
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What is the cortical reaction? How long does it take roughly?
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Sketch a human sperm. How does this differ from the urchin?
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Sketch a human oocyte. How does this differ from urchin?
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Where in the repro tract does fertilisation occur?
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Draw and label a female repro tract? Why is it so difficult for sperm to reach? What is the benefit of this?
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What evidence is there that female tract “selects” sperm?
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What are the steps of human fertilisation?
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Apart from bringing genetic material, what other role does sperm have in fertilisation?
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What is the role of sperm-egg recognition?
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What ion is responsible for the fertilisation signal?
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