Answer:the last one
Explanation: red blood cells are round in order to move easily through blood vessels.
The 3 checkpoints include G1 where the cell growth is checked, G2 where the integrity of the DNA/chromosome is checked, and M where the integrity of the metaphase plate is checked.
<h3>Cell cycle checkpoints</h3>
There are 3 regulatory checkpoints in the life cycle of cells:
- G1: the size of the cell, the presence of growth factors, and the integrity of the DNA are checked before the cell irreversibly commits to division.
- G2: the integrity of the DNA and the correctness of the replication process at the S-phase are checked.
- M: correct attachment of the spindle fibers to the chromosomes at the metaphase plate is checked.
More on cell cycle checkpoints can be found here: brainly.com/question/2128300
The most logical answer that I can think from Darwin's Theory of Evolution is that that species had been isolated from other possible panthers to mate with. So after generations of that isolated group of panthers their offspring would eventually become increasingly similar.
