I need help answering some questions So we were working with sea urchins, their

Question

I need help answering some questions So we were working with sea urchins, their sperm andeggs. 1.How quickly after insemination can a fertilization envelopebegin to rise from the egg surface? How long does they elevationprocess take? 2. Does the egg gain or lose volume during the process offertilization? 3.where does the mass of the mass of the fertilizationenvelope come from? I need help answering some questions So we were working with sea urchins, their sperm andeggs. 1.How quickly after insemination can a fertilization envelopebegin to rise from the egg surface? How long does they elevationprocess take? 2. Does the egg gain or lose volume during the process offertilization? 3.where does the mass of the mass of the fertilizationenvelope come from?

Explanation / Answer

Rupture of the cortical granules releases a mixture of enzymes,structural proteins and

mucopolysaccharides into the perivitelline space. One of theenzymes modifies the

vitelline layer so that extra sperm are detached. Anotherbreaks down the proteins that

bind the vitelline layer to the plasma membrane. Themucopolysaccharides cause the

diffusion of water into the perivitelline space, elevating thevitelline layer. The vitelline

layer receives structural proteins from the discharged granules,transforming it into the

“fertilization envelope.” Other proteins associate withthe fused plasma membrane-

cortical granule membrane, to form the “hyalinelayer.” Sperm that had bound to the egg

surface, but had not penetrated before rupture of the corticalgranules, now begin to

detach in a wave that follows the progress of this breakdown. Detachment of all but the

successful sperm is complete 60 seconds afterfertilization.

2. I'm not exactly sure on this one, put I think the gains volumedue to the diffusion of water into the perivitelline space.However, throughout the process of fertilization the egg turns intoan embryo that begins to divide into smaller cells.

3. The paragraph I pasted to explain question should also help youunderstand question 3

Hope this helps, this is a really cool lab.

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