All of the statements except one are true about mutations. which statement is false?
a) mutations must be present in parents and then passed to offspring.
b) mutations can be positive and produce organisms with improved traits.
c) mutations can be fatal to the organism that has a mutation, if the mutation is in a critical gene.
d) mutations can be silent, and not affect the organism that has them, if the mutation is in a non-critical area.

A is false

Explanation:

Mutation is a change that occurs in the DNA nucleotide sequence either due to mistakes when DNA is copied during cell division or as a result of environmental factors e.g. UV radiation.

Since all the cells of an organism contains DNA, there are lots of places mutation can occur. However, some mutations are not passed from parents to offsprings and do not matter for evolution. This form of mutation is called Somatic or acquired mutation and it occurs in non-reproductive cells. Hence, won't be passed down from parents to offsprings. This form of mutation majorly occurs when DNA cells get replicated during mitosis or when the cell is exposed to harsh environmental factors that damages DNA strands e.g Ultraviolet radiation.

Mutations are only hereditary i.e can be passed down from parents to offsprings, if they occur in reproductive cells (sperms and eggs). This kind of mutation is called Germ-line mutation.

According to the question, mutations must not always occur in the parents before an offsprings DNA undergoes mutation.