Question

question 22
in a diploid organism:
a there are two copies of every gene, both inherited from the mother.
b there are two copies of every gene, both inherited from the father.
c there are two copies of every gene, one inherited from the mother and the other from the father.
d there is one copy of every gene, randomly inherited from either mother or father.
e there are only two alleles present in the entire population.
question 23
in a cross between an individual with huntington disease and an unaffected individual, what are the chances their progeny will have the disease, considering that it is a dominant trait?
a 50%
b 75%
c 25%
d 0%

Explanation:

• Question 22: In diploid organisms, each cell contains two sets of chromosomes, one from the mother and one from the father. So, there are two copies of every gene, one inherited from each parent.
• Question 23: Huntington disease is a dominant - trait disorder. Let the allele for the disease be \(H\) and the normal allele be \(h\). An unaffected individual has the genotype \(hh\). An affected individual can be either \(HH\) or \(Hh\). If the affected individual is \(Hh\) (assuming a more common heterozygous case as \(HH\) is rarer), when crossed with \(hh\), the Punnett - square gives a 50% chance of the progeny having the disease (\(Hh\)) and 50% chance of being normal (\(hh\)).

Answer:

Question 22: C. there are two copies of every gene, one inherited from the mother and the other from the father.
Question 23: A. 50%