Which one of the following statement about the particular entity is true ?

Options

A. Centromere is found in animal cells, which produces aster during cell division
B. the gene for producing insulin is present in all human cells
C. Nucleosome is formed of nucleotides
D. DNA consists of a core of eight histones

Answer

To solve the question regarding which statement about a particular entity is true, we will analyze each statement one by one:

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- Statement: "Centromere is found in animal cells which produces ester during cell division."
- Explanation: The centromere is a region of a chromosome where two sister chromatids are joined. It is found in both animal and plant cells and is crucial during cell division for the attachment of microtubules. However, the statement incorrectly states that it produces ester, which is not true.
- Conclusion: This statement is **false**.

2. **Analyze the Second Statement:**
- Statement: "The gene for producing insulin is present in all human cells."
- Explanation: The gene responsible for insulin production is indeed present in all human cells. However, it is only expressed in specific cells, particularly the beta cells of the pancreas. The presence of the gene itself is what makes this statement true.
- Conclusion: This statement is **true**.

3. **Analyze the Third Statement:**
- Statement: "Nucleosome is formed of nucleotides."
- Explanation: Nucleosomes are the structural units of chromatin and are composed of DNA wrapped around a core of histone proteins. They are not formed from nucleotides; rather, nucleotides are the building blocks of DNA.
- Conclusion: This statement is **false**.

4. **Analyze the Fourth Statement:**
- Statement: "DNA consists of a core of 8 histones."
- Explanation: While histones are proteins that help package DNA into nucleosomes, DNA itself is made up of nucleotides, which consist of a nitrogenous base, a sugar, and a phosphate group. The statement incorrectly implies that DNA consists of histones.
- Conclusion: This statement is **false**.

### Final Conclusion:
After analyzing all statements, the only true statement is the second one: "The gene for producing insulin is present in all human cells." Therefore, the correct answer is **option B**.

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