The fertilized egg begins a rapid descent to the uterus. The period of rest in the tube appears to be necessary for full development of the fertilized egg and for the uterus to prepare to receive theegg. ... At the end of this transition period, the embryo becomes a mass of very organized cells, called a blastocyst.
Answer:
Explanation
A climax community (Figure below) is the end result of ecological succession. The climax community is a stable balance of all organisms in an ecosystem and will remain stable unless a disaster strikes. After the disaster, succession will start all over again.
It's the concentration of sense organs, nervous control, etc., at the anterior end of the body, forming a head and brain, both during evolution and in the course of an embryo's development.
Hey there,
The answer is Hydrosphere.
Hope this helps :))
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