C, when mutations are not always predictable they are random
An insect bite on the face produces a break in the skin which introduces the normal skin flora (usually <em>Staphylococcus </em>and <em>Streptococcus</em>) to the sterile subcutaneous tissue causing inflammation. The inflammation of the subcutaneous tissue is called cellulitis. Since the infection is in the face, then it can travel from the infected site to the meninges through the cavernous sinuses and cause bacterial meningitis.
The folds in the stomach lining are called rugae. On these rugae, you will find a thin line of mucous which helps protect the stomach lining. The innermost layer is called Simple Columnar Epithelium.
Lethal alleles cause the death of an organism prenatal or after the birth. Lethal alleles are usually a consequence of a mutation and they can be recessive, dominant or conditional. Since the lethal dominant alleles are harmful whether they are carried in homozygous (e.g.AA) or heterozygous (e.g.Aa) form, a strong selection against them is present and thus these alleles are much more rare.
