Question

X-rays cause mutation by____________.
A. Transition
B. Transversion
C. Deletion
D. Base substitution

Answer 1

Hint: X-rays have a wavelength ranging between 10 picometers to 10 nanometers and energy ranging from 124 eV to 124 eV which is way higher than visible light (1.8 eV to 3.1 eV). The ionizing radiation such as X-rays with high energy affects the structure of DNA directly.

Complete answer:
Let’s see the definition of mutation first. Mutation in DNA can be defined as a difference in genetic code in DNA than normal DNA. The abnormal genetic code can cause several kinds of genetic diseases and they can be inherited by progeny. Several factors cause mutations such as UV, radiation, and chemical mutagens.
X-rays are one kind of radiation that comes from the decaying radioactive elements. It comes under ionizing radiation where high energy production produces ions and free radicals. This radiation energy is so high that it can knock an electron out from its orbit of an atom and produces ions and free radicals that can break covalent bonds. In DNA covalent bonds are present between the phosphate group and sugar. The ionizing radiation from X-rays can break covalent bonds in DNA and cut the DNA into pieces. Our cells try to repair them but it is not efficient and causes deletion of nucleotides.

So, the correct answer is C which is “Deletion”.

Note:
The radiation is not harmful every time. Scientists have made use of these properties of ionizing radiation to kill cancerous tumors. When radiation therapy is provided, it not only kills the cancerous cells but affects and kills normal cells too.