Question

An organism with two identical alleles is-

• A. hybrid
• B. dominant
• C. homozygous
• D. heterozygous

Answer 1

The correct option is C

homozygous

The correct option is C

Explanation of correct option

1. Different variants of a gene that give rise to diversity or deviations are called alleles.
2. Humans are diploid organisms as they inherit one allele from each parent at a specific genetic locus.
3. If both alleles inherited from the parents are identical, it is called a homozygous allele.
4. Example- The presence of two alleles for brown eye color is an example of a homozygous allele that will result in a brown color phenotype.

Explanation of incorrect option

Option A

1. A hybrid organism has heterozygous or different alleles at a particular genetic locus.
2. Example- The presence of one allele for brown eye color and one for blue eye color results in the formation of heterozygous alleles with a brown phenotype.

Option B

1. If a particular allele produces a particular phenotype, in both homozygous or heterozygous conditions, it is said to be dominant over the other allele.
2. Example- Brown eye color allele is a dominant allele over the blue eye color allele.

Option D

A heterozygous organism has two different alleles for a particular genetic locus.

Final answer

An organism with two identical alleles is homozygous.