What distinguishes an allele from a gene?*1 pointAn allele is made of RNAAn allele is shorterAn allele is a variety of genean allele cannot be transferred during genetic modification

The correct answer is "An allele is a variety of gene".

Here's why:

1. Genes are segments of DNA that carry the instructions for the development, functioning, growth, and reproduction of cells. They are the basic physical and functional units of heredity.

2. Alleles, on the other hand, are different versions of the same gene. Each individual has two alleles for each gene - one inherited from each parent. These alleles may be identical or different.

3. If the two alleles are identical, the individual is homozygous for that gene. If the alleles are different, the individual is heterozygous.

4. While a gene determines a characteristic, an allele determines the form of that characteristic. For example, a gene may determine eye color, while an allele determines whether the eyes are blue, brown, green, etc.

5. Therefore, an allele is not made of RNA, it is not necessarily shorter, and it can indeed be transferred during genetic modification. The key difference is that an allele is a variety of a gene.