If there are 46 chromosomes present before the synthesis phase, how many chromatids are there when the cell reaches the gap phase 2?

1. ### Break Down the Problem

To find the number of chromatids at the gap phase 2 (G2) after the synthesis phase (S phase), we need to consider the following:

1. The number of chromosomes before synthesis.
2. The replication process that occurs during synthesis.

2. ### Relevant Concepts

• A chromosome is made up of two sister chromatids after DNA replication during the synthesis phase (S phase).
• Before synthesis, if a cell has $n$ chromosomes, after synthesis, it will have $2n$ chromatids because each chromosome duplicates to form two chromatids.

3. ### Analysis and Detail

1. Before S phase, the cell has 46 chromosomes.
2. During S phase, each of these chromosomes duplicates, resulting in: $\text{Number of chromatids} = 2 \times \text{Number of chromosomes before S phase}$
3. Therefore: $\text{Number of chromatids} = 2 \times 46 = 92$

4. ### Verify and Summarize

Thus, after the synthesis phase, every chromosome duplicates, leading to a total of 92 chromatids. This count holds until the cell proceeds to the next phase (M phase).

Final Answer

The number of chromatids present in the cell at gap phase 2 (G2) is 92.