I think the correct answer from the choices listed above is option B. Keratin is the protein in mammals which shows only a primary and secondary structure. Keratin is a fibrous protein forming the structural constituent of hair, feathers, hoofs, claws and many others.
The pit that marks the location of the umbilical cord after birth is known as the navel or belly button. All animals that grow placenta during fetal development will have a navel or belly button. The scientific name of the structure is the umbillicus. It can be a depression in some individuals or raised in others.
Answer:
Genes and alleles assort independently during gamete formation. The possible gametes for the following will be: AB, aB, Ab, ab. The alleles will assort independently for each of the genes, hence there are equal chances for a gamete to carry the AB, aB, Ab or ab genes.
As Mendel's studies explained that alleles assort independently into gametes hence there are equal chances for a gamete to carry all the variability.