Ultraviolet radiations cause mutations due to

Options

A. formation of thymine dimers/ thymidine
B. Deletion f base pairs
C. Addtion of base pairs
D. Methylation of base pairs.

Answer

**Step-by-Step Solution:**

1. **Understanding Ultraviolet Radiation:** Ultraviolet (UV) radiation is a type of electromagnetic radiation that can cause damage to DNA in living organisms.

2. **Identifying the Type of Mutation:** The primary type of mutation caused by UV radiation is the formation of thymine dimers. Thymine dimers occur when two adjacent thymine bases bond together instead of pairing with their complementary adenine bases.

3. **Mechanism of Mutation:** When UV light hits the DNA, it can cause the two thymine bases on the same DNA strand to link together, forming a dimer. This mispairing leads to errors during DNA replication.

4. **Consequences of Thymine Dimers:** The formation of thymine dimers can result in a transition mutation, specifically a change from cytosine (C) to thymine (T) during DNA replication. This is a significant mutation that can lead to further genetic alterations.

5. **Link to Cancer:** The mutations caused by UV radiation, particularly the formation of thymine dimers, have been linked to an increased risk of cancer, as these mutations can disrupt normal cellular functions and lead to uncontrolled cell growth.

6. **Final Answer:** Therefore, the answer to the question "Ultraviolet radiations cause mutations due to" is the formation of thymine dimers.

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