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33 Cards in this Set
- Front
- Back
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How are gametes released?
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by gonoduct and gonopore
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What is the acrosomal reaction?
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Fusing of sperm with egg, and "engulfing" of the sperm
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What initiates the acrosomal reaction?
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When sperm approaches the jelly layer
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What is the acrosomal membrane?
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On he head of the sperm. It fuses with the sperm plasmalemma resulting in exocytosis. Acrosomal granules release enzymes
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How does the sperm penetrate the jelly layer?
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Enzymes are secreted from acrosomal granules. They help the sperm penetrate the egg jelly layer.
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Once the sperm penetrates the jelly layer, what happens?
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Sperm binds to the vitelline envelope. Then the actin beneath the acrosomal granule polymerizes to form the acrosomal filament.
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What does actin do?
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Actin is beneath the acrosomal granule and forms the acrosomal filament.
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What forms the acrosomal process?
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The acrosomal filament is covered with acrosomal membrane. Together = the process.
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What does the acrosomal process do?
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Acrosomal filament is covered with acrosomal membrane, and the two structures are the process. The process get contact between the egg and sperm within the vitelline envelope. Plasmalemma fuses. Sperm is engulfed
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What initiates the cortical reaction?
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fusion of egg and sperm
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What do the cortical granules do in the cortical reaction?
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Egg and sperm fuse. So the cortical granules from beneath eggs plasmalemma fuse with the plasmalemma in a wave. Contents are expelled and released into the space between the plasmalemma and vitelline envelope.
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What is the role of the vitelline envelope?
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In the coritcal reaction, cortical granules are released into the spece between the plasmalemma and the envelope. When this happens, the vitelline envelope hardens and moves away from the egg. This forms the fertilization membrane and perivivelline space
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what forms the fertilization membrane and perivitelline space?
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When the vitelline envelope hardens and moves away from the egg. Caused by the cortical granules which released contents in between the vitelline envelope and the plasmalemma causing the vitelline envelope to harden and move away
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What is the role of the hyaline proteins? What part do they play?
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They are in the cortical reaction. They form a layere around the blasomeres to keep them together during cleavage
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what layer keeps blasomeres together during cleavage
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hyaline proteins
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How is polyspermy prevented?
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Fast: electric potential change. Depolarize the plasmalemma to decrease sperms likeliness of fusing to the egg.
Slow: Barrier by increasing perivitelline space and elevating fertilization membrane. Egg surface properties are changed by calcium ions in the egg |
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What type of cleavage does the thing undergo?
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Holoblastic or total cleavage
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What is a cleavage furrow
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area formed because of cleavage
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name the creation of cleavage
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Blastomeres from 2-8 cells
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At 12 cell stage what are blastomeres called
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Micromeres, macromeres, and mesomeres.
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What is a morula
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12-16 cell stage ball. Circle of berries MORULA More berries!
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What do you call a circle of berries
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morula
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What is blastulation
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formation of blastocoel and blastula
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what is the blastocoel
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central cavity formed in the blastula stage.
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what forms the blastocoel
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arrangement of blastomeres to form a hollow ball.
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What does invagination of the blastula do
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forms the blastopore - end of blastula
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What is the blastopore
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invagination of the blastula
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What forms the archenteron
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invagination of the blastopore until it reaches the other pole and forms a tube
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What is an archenteron
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a primitive gut
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What are deuterostomes?
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1st opening = anus
2nd opening = mouth |
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what is a spicules
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formed in gastrulation. Spicules begin to form a larval skeleton at the end of the gastrula stage.
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What is pluteus larvae
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The embryo flattens after gastrulation and projections form which include 2 anal and 2 oral arms
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what happens to the spicules in the pluteus larvae stage
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Spicules increase in size and provide stability and structure to the embryo
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