In general terms, normally a cell in your body crosses a checkpoint in the cell cycle when
a. it receives a "go-ahead" signal directly from your brain
b. concentrations of proteins in the cytoplasm reach the appropriate level
c. it receives a "go-ahead" signal from your external environment
d. concentrations of dna in the nucleus reach the appropriate level
e. a mutation in the dna occurs

B. Concentrations of proteins in the cytoplasm reach the appropriate level

Explanation:

We can say that the cell cycle checkpoints is an important cell cycle control. In this regard, it is important to note that within a cell, the passage from one phase to another is controlled by regulatory factors that are characteristically proteinic and act at the so-called cell cycle checkpoints.

A cell passes the first checkpoint when protein concentrations in the cytoplasm reach the appropriate level.

it would affect precipitation by causing flooding in some areas of the world due to climate increasing, causing the glaciers in the northern and southern pole of our planet to melt.

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