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Mitosis question (please help)

Why is it during the first four mitotic divisions, the embryo does not increase in volume though the total number of cells increases. :h:
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Avatar for RMNDK
RMNDK
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Original post by Dancheng
Why is it during the first four mitotic divisions, the embryo does not increase in volume though the total number of cells increases. :h:


Ah, that's because the division of the zygote is slightly different to a division of a normal body cell in which the growth phases are left out.

As a result, the resulting cells (blastomeres) are half the size of the original zygote.
And thus at each division, despite the cytoplasmic volume of the cells halving, the number of cells doubles, effectively keeping volume constant.

If you have a ball of playdoh, mitosis is like, adding the same amount of playdoh onto it to get a big ball, then break it into two pieces

Embryo cleveage is like splitting that playdoh into two smaller pieces. More balls, no added playdoh
Reply 2
Avatar for Dancheng
Dancheng
OP
Original post by RMNDK
Ah, that's because the division of the zygote is slightly different to a division of a normal body cell in which the growth phases are left out.

As a result, the resulting cells (blastomeres) are half the size of the original zygote.
And thus at each division, despite the cytoplasmic volume of the cells halving, the number of cells doubles, effectively keeping volume constant.

If you have a ball of playdoh, mitosis is like, adding the same amount of playdoh onto it to get a big ball, then break it into two pieces

Embryo cleveage is like splitting that playdoh into two smaller pieces. More balls, no added playdoh


Cheers man!

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