Somatic mutations are always?

Question

a)heritable

b)lethal

c)carcinogenic

d)spontaneous

e)none of the above

I know that Somatic cells are any cells forming the body of an organism, as opposed to germline cells. In mammals, germline cells (also known as "gametes") are the spermatozoa and ova which fuse during fertilization to produce a cell called a zygote, from which the entire mammalian embryo develops. Every other cell type in the mammalian body—apart from the sperm and ova, the cells from which they are made (gametocytes) and undifferentiated stem cells—is a somatic cell: internal organs, skin, bones, blood, and connective tissue are all made up of somatic cells.

Would it be lethal then? can I have some help on this please?

Answer 1

E) None of the above

If you know that much about the germ cells then you should be able to figure out why a somatic mutation cannot be heritable (so A is out). Since none of the somatic cells become germline cells the mutation cannot be passed on.

It doesnt have to be lethal. You know when you get a sunburn, that is causing mutations some of which are repaired and some of which are not. If the mutated cell survives your sunburn, it will still remain alive and so will you (most likely). B is out.

Take the same sunburn but this time that mutation happened to be in a very important gene that controls the regulation of many other genes which could lead to cancer, BUT it doesnt ALWAYS. (C is out).

D is tough. Point mutations caused by the sun and its UV rays are spontaneous. That is, they occur anywhere in the genome. However, there are several examples of non-spontaneous mutations. Consider a retrovirus which can integrate into its host's DNA. In many cases this can only happen at specific sequences in the genome. So all somatic mutations are not ALWAYS spontaneous.

It must be E.