Checkpoint 3 Checkpoint 2
M M
G2
G1
Checkpoint 1
S
Go
Figure 1. Diagram of the cell cycle with key checkpoints
Which of the following describes a mutation that would lead to an increase in the frequency of nondisjunction?
A mutation affecting checkpoint 1 proteins that forces cells to enter G0

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

1. is geographic distribution

2 is increasing complexity

3 is transitional forms

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers