Which traits are codominant or incompletey dominant? (these traits don't have a clear dominant or recessive, the heterozygous condition shows a "blending or a "middle" condition)

Codominant-  traits don’t have a clear dominant or recessive

Incomplete dominance-  the heterozygous condition shows a “blending” or a “middle” condition

Explanation:

In codominance, the traits are expressed equally in the phenotype thus they don't have a clear dominant or recessive state. For example the ABO blood group alleles. The alleles A and B are codominant each being expressed equally.

In incomplete dominance the traits show intermediate expression where one allele expresses itself more strongly than the other. An example in man is seen in the inheritance of the disease sickle cell anaemia. Heterozygote who carry the sickle cell gene are said to have sickle cell trait and as such the carrier allele (HBa) has a stronger influence on the phenotype than the dominant alle (HBs).

c) 50% there are four chromosomes. after crossing over, 2 of the four have been changed. that means any gamete has a 2 in 4 chance or 50% chance of receiving the mutated chromosome.