Question

in a particular species of octopus, long arm length is completely dominant over short arm length.
if an octopus of this species has short arms, what is its genotype?
○ dd or dd
○ dd
○ dd only
○ d

Explanation:

In genetics, when a trait is completely dominant, the dominant allele masks the recessive allele. Let's assume \(D\) represents the allele for long - arm length (dominant) and \(d\) represents the allele for short - arm length (recessive). An organism shows the recessive phenotype (short arms in this case) only when it has two recessive alleles. If there is a dominant allele (\(D\)), the dominant phenotype (long arms) will be expressed. For example, \(DD\) and \(Dd\) genotypes will show the long - arm phenotype because of the presence of the dominant \(D\) allele. The genotype \(d\) is not a valid diploid genotype (diploid organisms have two alleles for a given gene).

Answer:

\(dd\)