Answer:
A. fecundity
the maximal potential reproductive capacity of an individual in a population
B. semelparity
species that only reproduces once and then dies
C. iteroparity
species that reproduce multiple times over their lifespan
D. life history
inherited pattern of resource allocation under the influence of natural selection and other evolutionary forces
<span>Alleles are two different forms of single gene that are located in specific position on a specific chromosome. It can be classified into two allele pairs: homozygous and heterozygous. In homozygous, both alleles are the same whether they are both dominant or recessive; while in heterozygous, one allele is dominant and the other is recessive.</span>
Ans.
HD (Huntington's disease) is a genetic neurological disorder that occurs due to damage and death of brain cells. it is caused by an autosomal dominant mutation in HTT (huntingtin) gene, having a trinucleotide repeat section that makes HTT protein.
The mutation leads to an increase in this nucleotide repeat count, associated with formation of altered or mutated huntingtin protein. These altered proteins show deleterious affect on brain cells and result in Huntington's disease.
Thus, the correct answer is 'option A). a mutated gene.'