Question

Gene mutations can be caused by all of the following except
1. insertion or deletion of nucleotide bases in a DNA sequence.
2. a single nucleotide base being replaced by a different base.
3. by the fertilization of an egg cell by a sperm cell.
4. mutagenic agents such as X-rays, free radicals and chemicals.

Answer 1

These changes can be caused by environmental factors such as ultraviolet radiation from the sun, or can occur if an error is made as DNA copies itself during cell division. Acquired mutations in somatic cells (cells other than sperm and egg cells) cannot be passed to the next generation.

correct answer is 3.

by the fertilization of an egg cell by a sperm cell.

Answer 2

Answer:

3. by the fertilization of an egg cell by a sperm cell.