Answer;
Primitive streak.
At the onset of the embryonic period, the primitive streak appears. It will eventually become the neural tube.
Explanation;
The primitive streak is a transient structure which forms on day 15 of human development.
It marks the start of gastrulation; the process in which the inner cell mass in converted into the trilaminar embryonic disc.
It originates from the anterior epiblast.
The abbreviation for adenosine triphosphate is ATP
Answer:
1. it has not defined length..
2. it digest good in food vacoule
hlo
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The molecular clock is a scientific technique which presents a means of estimating evolutionary rates and timescales using genetic data. It uses mutation rate of biomolecules when two or more life forms diverged to estimate the time. Answer is B.