The alternate form of a gene is

Analyze the question The question asks for the term used for the alternate form of a gene, meaning one of the different versions of the same gene found at the same position (locus) on homologous chromosomes.

Explain the concept A gene is a unit of heredity that controls a particular trait, such as flower colour or seed shape. Many genes exist in more than one version. These different versions are called alleles.

For example, the gene for height in pea plants has two alleles:

• T (tall)
• t (short)

An individual inherits one allele from each parent. The pair of alleles determines the trait:

• TT is homozygous dominant
• Tt is heterozygous
• tt is homozygous recessive

Go through the options

• A. Alternate type: This is not a recognized genetics term.
• B. Dominant character: This is a trait that shows up even when only one copy of its allele is present. It describes how an allele is expressed, not the alternate form of a gene.
• C. Recessive character: This is a trait that shows only when two copies of its allele are present. It also describes expression, not the alternate form itself.
• D. Allele: This is correct. An allele is an alternative form of a gene at the same locus.

Answer The correct option is D. Allele.

Exam tip Link the word allele with alternative. Both start with "al". Dominant and recessive describe how alleles behave. They are not the alleles themselves.