Answer:
G1/S checkpoint
Explanation:
G1/S checkpoint is one of the points in the cell cycle, between growth phase 1 and DNA synthesis phase, where a cell that has been damaged is sensed by DNA repair enzymes and further degraded by apoptosis. In cancer cells, there is mutation in these DNA repair enzymes and thus nothing to correct the cells from dividing even when damaged and thus there is no arrest of division and cells continue dividing
21. on first attachment is secondary succession
22. is the degree of variation of life....
genetic, species or ecosystem within a specific area, system or planet
23. the last one is wrong = )
Hi!
It would be D, because trilobites were aquatic.
Hope this helps!
I think it is D but I'm not sure, however, 4 seems pretty right.
