Which of the following statements are not true?

Options

A. In animals cells during S phase DNA replication being in nucleus and centroide duplication in cytoplasm
B. During G1 protein are synthesized and cell continues to grow synthesized and cell continues to grow
C. All cells in adult animals appear to exhibit cell division
D. All are true

Answer

To determine which of the statements is not true, let's analyze each option step by step.

### Step 1: Analyze Statement A
**Statement A:** "In animal cells during S phase, DNA replication begins in the nucleus and centriole duplication in the cytoplasm."

- **Explanation:** This statement is true. During the S phase of the cell cycle, DNA replication occurs in the nucleus, where the genetic material is duplicated. Additionally, centriole duplication occurs in the cytoplasm, which is essential for proper cell division.

### Step 2: Analyze Statement B
**Statement B:** "During G1, proteins are synthesized and the cell continues to grow."

- **Explanation:** This statement is also true. The G1 phase (Gap 1 phase) is characterized by cell growth and the synthesis of proteins necessary for DNA replication and cell division. Cells prepare for the S phase during this time.

### Step 3: Analyze Statement C
**Statement C:** "All cells in adult animals appear to exhibit cell division."

- **Explanation:** This statement is not true. While many cells in the body can divide, some cells, such as neurons (nerve cells) and cardiac muscle cells (heart cells), do not typically undergo cell division in adults. These cells are often terminally differentiated and cannot be replaced if they are damaged.

### Step 4: Analyze Statement D
**Statement D:** "All are true."

- **Explanation:** Since Statement C is not true, this statement is also false.

### Conclusion
Based on the analysis, the statement that is not true is **Statement C**: "All cells in adult animals appear to exhibit cell division."

### Final Answer
The answer is **C**.

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