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.
I believe it is amino acids?
The tissue you are referring to here is the xylem, a <u>vascular tissue</u>, whose basic function is to transport water and nutrients from the roots to the rest of the plant.
Democritus is a Greek theorist that believes that atom is the smallest part of the substance. Atom, as he defined, is an indivisible entity. Leuccipus was Democritus' teacher who also believed on that notion. All matter are made up of atoms. If atoms are intact, the property of the substance is firm and solid while if the atoms are much apart, it would be described as a gas. Aristotle had a different belief of matter. He believed that the composing entities of matter are the four elements. However, this notion was rejected and proven through scientific inquiries about atoms and subatomic particles
It has more similarity to fossils in layer A than layer D.