This is an example of an Epigenetic effect.
Explanation:
It is the study of heritable changes in the expression of genes, that are not involved in the changes present in DNA sequence. It is regular and naturally occurred, sometimes factors are responsible like age, lifestyle and disease state.
At times it leads to more damaging effect that can cause cancer. So this is also related to various fatal disease. During adulthood epigenetic effect remains stable. It does not occur in mother womb, but during the lifespan. This epigenetic effect can be reversed.
Answer: It's A. The sequence of DNA bases is different
The correct answer is nucleus
When you inject a vassen into your blood streme it attacks the virus cells
