Question

An allele is one of the alternative forms of a gene that governs a trait. If a fern plant is heterozygous for a particular trait, how can the alleles that control that trait be described? A. one dominant, one recessive B. two dominant C. three recessive, one dominant D. two recessive

Answer 1

"Hetero" means different. So the plant has two different alleles; one dominant and one recessive as in (A).

Answer 2

Answer:

The correct answer is A. one dominant, one recessive

Explanation:

A gene can have many alternative forms called alleles. These alleles can be present in homozygous condition or heterozygous condition. In homozygous condition chromosome contains two same forms of an allele of a gene. In heterozygous condition a chromosome contains two different forms of an allele of a gene.  

These alleles can be dominant or recessive. A dominant allele can be expressed in both homozygous and heterozygous condition, but a recessive allele will only express in homozygous condition.

So If a fern plant is heterozygous for a particular trait then it contains one dominant and one recessive allele because in heterozygous condition two different forms of allele is present. Therefore the right answer is A.