Value (constant value) of Dna refers to

Options

A. total amount of DNA per somatic cell
B. total amount of DNA/base pairs per genome
C. amount of DNA in autosomes
D. amount of DNA which is heritable and present in autosomes

Answer

To answer the question regarding the constant value of DNA, we can break down the information step by step:

### Step-by-Step Solution:

1. **Understanding C Value**: The constant value of DNA is referred to as the "C value." It represents the total amount of DNA contained within the somatic cells of an organism.

**Hint**: Remember that the C value is a measure of the total DNA content in a cell.

2. **Definition of C Value**: The C value is defined as the amount of DNA in a haploid set of chromosomes. In simpler terms, it is half the amount of DNA found in diploid somatic cells.

**Hint**: Think about how diploid cells contain two sets of chromosomes, and the C value reflects just one of those sets.

3. **Diploid Organisms**: In diploid organisms, like humans, there are two sets of chromosomes (one from each parent). Therefore, during gametogenesis (formation of gametes), the DNA is halved, resulting in haploid cells.

**Hint**: Recall that diploid means two sets and haploid means one set of chromosomes.

4. **Total Amount of DNA**: The C value can also be interpreted as the total amount of DNA per genome, which refers to the complete set of genetic material present in an organism.

**Hint**: The genome includes all the genetic information necessary for the organism's development and functioning.

5. **Exclusion of Other Options**: The question mentions various aspects of DNA, such as the total amount of DNA per somatic cells, DNA in autosomes, and heritable DNA. However, the C value specifically refers to the total amount of DNA in a haploid set, not just in somatic cells or autosomes.

**Hint**: Focus on the definition of C value rather than other DNA-related terms.

### Final Answer:
The constant value of DNA, known as the C value, refers to the total amount of DNA in a haploid set of chromosomes, which is half the amount of DNA present in diploid somatic cells.