I believe the answer is c)
Backcross, the mating of a hybrid organism, offspring of genetically unlike parents,with one of its parents or with an organism genetically similar to the parent.
Answer: The correct answer is-
an agent that causes a mutation in DNA.
Mutagen is an agent or a substance that causes permanent change in the genetic material of living organisms ( DNA, deoxyribonucleic acid). This process is called mutation.
A mutagen can be a chemical, physical or biological agent that causes mutation in the DNA.
Example- Physical agents such as -
- Ionizing radiations like alpha particles, gamma rays, X-rays that brings break in the DNA and cause other damages.
- Ultraviolet radiations that creates pyrimidine dimers ( T=T) and causes replication errors if damage is not repaired.
<u>Answer</u>:
Option d. many small changes can create a whole new species
<u>Explanation</u>:
In the natural selection when the animals gets adapted in a better manner, they tends to thrive in and gets the ability to reproduce more which leads to the formation of the new bigger species. It leads to a change when the individual with few characteristic have the survival chance more also the reproductive rate as compared to others individuals in the group and also passes these inheritable genetic traits to the offspring.