Biology / Unit 13 Bio 3353 short lesson, about 20 seconds
Cleavage and Blastula Formation
Captions available
The idea
Cleavage divides a fertilized egg rapidly through mitosis without overall growth, producing a solid ball of smaller cells that hollows into a blastula past roughly a hundred cells.
In practice
Cleavage divisions occur so fast the embryo's total size barely changes despite the rising cell count.
Where people slip
Cleavage divides cell number without growing total mass, unlike ordinary mitotic growth elsewhere in development.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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