Question

what is the term for the physical expression or appearance of a particular trait?
a. dominance
b. allele
c. genotype
d. phenotype

which of the following best describes a heterozygous genotype?
a. having only recessive alleles
b. having only dominant alleles
c. having two identical alleles for a gene
d. having two different alleles for a gene

what does a homozygous genotype indicate?
a. two different alleles for a gene
b. a recessive trait being expressed
c. a dominant trait being expressed
d. two identical alleles for a gene

Explanation:

1. The phenotype is the physical expression or appearance of a trait. Dominance refers to the relationship between alleles where one masks the other. An allele is a variant form of a gene. Genotype is the genetic makeup.
2. A heterozygous genotype has two different alleles for a gene. Having only recessive alleles is homozygous - recessive, having only dominant alleles is homozygous - dominant, and having two identical alleles is homozygous.
3. A homozygous genotype indicates two identical alleles for a gene. Two different alleles is heterozygous. Whether a recessive or dominant trait is expressed depends on the nature of the alleles (dominant - dominant, dominant - recessive, recessive - recessive).

Answer:

1. d. Phenotype
2. d. Having two different alleles for a gene
3. d. Two identical alleles for a gene