Question

1. All mutations are harmful.

a) True

b) False

2. Which of the following is TRUE about mutations?

a) Mutations are more likely to occur if they result in a useful trait

b) Mutations can be inherited.

c) Mutations only occur during DNA replication

d) Mutations do not occur in organisms that reproduce asexually

3. Which of the following would increase the chances of getting a mutation?

a) Wearing a hat outside

b) Putting sunscreen on your face and arms

c) Playing soccer at noon when the sun is strongest

d) Washing a car in the shade

Answer 1

1. (b)

All mutations are not harmful. The effects of mutations can be useful, harmful or neutral not always causing deleterious effects. The mutations can lead to generation of new characteristics and further evolution of a trait. The mutations can cause gene change but not alteration of protein has no effect. Only the mutations causing entire amino acid sequence change has deleterious effects.

2. (b)

Mutations can be inherited called germline mutations.

A gene mutation is a permanent alteration in the DNA sequence which makes up a gene, such that the sequence differs from earlier conventional sequence. Hereditary mutations are inherited from a parent and are present in every cell in the body. These mutations are also called germline mutations as such they are present in the parent’s egg or sperm cells. The DNA from fertilized egg of both parents has a mutation, the child that grows from the fertilized egg will have the mutation in all the cells. Example of inherited mutations include cystic fibrosis, sickle cell anemia, Tay-Sachs disease, phenylketonuria,color-blindness,etc.,

3. (c)

playing soccer in the noon when sun is strongest increase the chances of getting a mutation.

The change in the DNA can be caused by environmental factors such as ultraviolet radiation from the sun. UV-A radiation in the sunlight having wavelength of 315-400nm commonly causes the creation of a free radical which interacts with and oxidizes DNA bases. These oxidized bases don't pair correctly during replication and can cause cancer. The UV B radiation in wavelength of 280-315nm affect skin’s top layer, cause skin cancer and most of sunburns.The mutation occurs in a gene called KNSTRN, which function in helping cells divide their DNA equally during cell division.