The pedigree chart below shows the individuals in a family who exhibit a certain trait. based on the info in the chart, which of the following provides the best evidence that this is a recessive trait?

a. couple 3-4 in the 2nd generation produced children who are identical twins.

b. couple 1-2 in the second generation produced children who do show the trait.

c. couple 1-2 in the 1st generation produced children who do show the trait.

d. couple 3-4 in the 2nd generation produced children who do not show the trait.

Nhumans, abo blood types refer to glycoproteins in the membranes of red blood cells. there are three alleles for this autosomal gene: ia, ib, and i. the ia allele codes for the a glycoprotein, the ib allele codes for the b glycoprotein, and the i allele doesn't code for any membrane glycoprotein. ia and ib are codominant, and i is recessive to both ia and ib. people with type a blood have the genotypes iaia or iai, people with type b blood are ibib or ibi, people with type ab blood are iaib, and people with type o blood are ii. if a woman with type ab blood marries a man with type o blood, which of the following blood types could their children possibly have? in humans, abo blood types refer to glycoproteins in the membranes of red blood cells. there are three alleles for this autosomal gene: ia, ib, and i. the ia allele codes for the a glycoprotein, the ib allele codes for the b glycoprotein, and the i allele doesn't code for any membrane glycoprotein. ia and ib are codominant, and i is recessive to both ia and ib. people with type a blood have the genotypes iaia or iai, people with type b blood are ibib or ibi, people with type ab blood are iaib, and people with type o blood are ii. if a woman with type ab blood marries a man with type o blood, which of the following blood types could their children possibly have? a, b, ab, and o ab and o a, b, and o a and b