Q: Locus refers to the position of what on a chromosome, which controls the characteristics of an organism?


Read this paragraph and choose the correct option from the provided answers:

Today, we known that characteristics of organisms are controlled by genes on chromosomes (see Figure below ). The position of a gene on a chromosome is called its locus . In sexually reproducing organisms, each individual has two copies of the same gene, as there are two versions of the same chromosome ( homologous chromosomes ). One copy comes from each parent. The gene for a characteristic may have different versions, but the different versions are always at the same locus. The different versions are called alleles . For example, in pea plants, there is a purple-flower allele ( B ) and a white-flower allele ( b ). Different alleles account for much of the variation in the characteristics of organisms.

 Choices:

- genome

- gamete

- rna

- gene


A:
gene