Satellite DNA consists of

Options

A. large arrays of tandemly repeating non coding DNA
B. small arrays of coding DNA
C. moderate arrays of coding DNA
D. large arrays of non-repeating, non-coding DNA

Answer

**Step-by-Step Solution:**

1. **Understanding Satellite DNA**: Satellite DNA is a specific type of DNA found in the genomes of many organisms. It is characterized by its structure and function.

2. **Characteristics of Satellite DNA**:
- **Tandemly Repeating**: Satellite DNA consists of very large arrays of tandemly repeating sequences. This means that the same sequence of DNA is repeated multiple times in a row.
- **Non-Coding DNA**: The sequences in satellite DNA do not code for proteins; hence, they are referred to as non-coding DNA.

3. **Role in Chromatin Structure**: Satellite DNA is a significant structural component of heterochromatin, which is a tightly packed form of DNA. This packing is crucial for the structural integrity of chromosomes.

4. **Function in Centromeres**: Satellite DNA is also a main component of functional centromeres, which are essential for the proper segregation of chromosomes during cell division.

5. **Repetitive Nature**: The sequences in satellite DNA are highly repetitive, meaning that they are repeated many times within the genome.

6. **Applications**: Satellite DNA has practical applications, such as in DNA fingerprinting, which is used in forensic science and paternity testing.

7. **Evaluating Options**:
- The first option states that satellite DNA consists of large arrays of tandemly repeating non-coding DNA. This is correct.
- The second option mentions small arrays of coding DNA, which is incorrect.
- The third option refers to moderate arrays of coding DNA, which is also incorrect.
- The fourth option states large arrays of non-repeating non-coding DNA, which is incorrect.

8. **Conclusion**: The correct answer is the first option: "large arrays of tandemly repeating non-coding DNA."

**Final Answer**: Satellite DNA consists of large arrays of tandemly repeating non-coding DNA.

---