What phenotypic ratio would you expect as a result of a test cross between a dihybrid organism and one that is homozygous recessive for alleles at two independent loci? a. 3: 1b. 9: 3: 3: 1c. 1: 1: 1: 1d. 1: 2: 1e. 9: 4: 2: 1

c. 1:1:1:1

Explanation:

Dihybrid organism is an organism that is heterozygous at two different genetic loci. So, for example if there are two loci A and B, dihybrid organism would have AaBb genotype. Homozygous recessive for alleles at two loci has the genotype aabb.

P: AaBb  x  aabb

The possible genotypes are: AaBb  Aabb  aaBb  aabb

organisms that lack symmetry are called asymmetrical and belong to phylum porifera/sponges.

organisms with specialized stinging cells belong to phylum cnidaria. stinging cells are called cnidoblast cells.

cnidarians show two morphological forms : polyp (sessile) and medusa (mobile)

filter feeding is observed in porifera members.  

alternation of generation is observed in coelenterata or cnidaria. there is alternation of asexual polyp form and sexual medusoid form. it is also referred as metagenesis.

the statement is true