The tricuspid valve has three cusps that are essential components of the valve. (Hence "tri-" in tricuspid. ) The semilunar valve is called semilunar because each semilunar valve has cusps in the shape of half moons. Hope this helps to contrast their structure!
You are right. di means two
(1) All the genotypes are as follows: AABB, AaBB, AABb, AaBb, aaBB, aaBb, AAbb, Aabb, aabb.
(2) Assuming that Aa is dominant and Bb is recessive, there will be 9 phenotypes with both A and B allele dominant (i.e. AaBb, AABb); there will be 3 phenotypes with just the A allele dominant (i.e. Aabb, AAbb); there will be 3 phenotypes with just the B allele dominant (i.e. aaBb, aaBB); and there will be 1 phenotype with both alleles recessive (i.e. aabb). The phenotypic ratio in this case is 9:3:3:1.
(3) The probability of producing an offspring with the aabb genotype is 1/16 or 6%.
Answer:
Both parents are heterozygous carriers.
Explanation:
Both parents are heterozygous carriers. Sickle Cell Anaemia is usually referred to as a recessive condition since an individual must have two copies of the sickle gene in order to have the disorder.
Since neither of the parents is ill, both of them must be heterozygous carriers for the child to have the disorder