The agents that caused a mutation in DNA and chromosomes are mutagens. Phenotype expresses traits, karyotype is a complete set of chromosomes.
What do you mean by Mutation?
A Mutation may be defined as the sudden, stable, and inheritable changes in the genetic material of an organism.
Mutagens are those agents which are responsible for the causing of mutation. Some of the examples of mutagens are UV radiations, X-rays, ethidium bromide, etc.
Therefore, the agents that caused a mutation in DNA and chromosomes are mutagens.
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