Question

Which of the following can cause DNA damage and mutations in humans?
A. Absorption of UV-A and UV-B
B. Absorption of UV-B
C. Absorption of UV-A
D. Absorption of UV-A and UV-C

Answer 1

A mutation is an alteration of the genetic material of life, DNA. The DNA of an organism determines how it feels, how it acts, and the physiology of the organism. A change in the DNA of an organism may therefore cause changes in all aspects of its life. For evolution, mutations are crucial; they are the raw material of genetic variation.

Complete answer:
The best-known example of how DNA gets damaged by the atmosphere is skin cancer caused by the abundance of UV radiation in the form of sunlight (and, to a lesser degree, tanning beds). Another example is cigarette smoke damage, which may lead to lung cell mutations and eventual lung cancer. In addition to environmental substances, DNA is often oxidatively impaired by metabolism by-products such as free radicals. In fact, up to one million DNA changes per day can affect a particular cell.
As described above, UV exposure triggers an important DNA damage response (DDR). Only UV A and UV-B can enter Earth's atmosphere from the 3 types of solar UV radiation. Thus, these two forms of UV radiation are most of concern to humans, especially because the continuous loss of the ozone layer causes the earth to have higher levels of UV radiation. UV-B absorption induces dimerization of pyrimidine. This damages DNA and causes human mutations. The mutation of pyrimidine or thymine is induced.
Therefore, 'UV-B absorption' is the right alternative.

Note: DNA mutations are part of life in an organism. A series of changes that undermine their credibility is being revealed to our genetic code. However, the DNA repair machine has a robust system of checks and balances. Often disease-related errors that fall through cracks are often a cause of variance in longer-term procedures like evolution and natural selection.