Answer:
The options to this question are:
A) allele
B) codon
C) nucleotide
D) chromosome
The answer is A) allele
Step-by-step explanation:
RNA and DNA are the two nucleic acids in living organisms used for transferring and storing genetic information. Deoxyribonucleic acid (DNA) is the genetic material in living organisms that contains segment coding for useful products/proteins and transmits genetic information from one generation to another. These segments are called GENES.
However, genes contain an alternate form responsible for genetic variation in the traits coded for by them. These alternate or variant form of a gene is called ALLELE. In a diploid organism like human, each trait is encoded by genes which contain contrasting pair of alleles that allows variation for that particular trait i.e. two alleles for each gene. For example, height trait in humans are encoded by gene, which possess two alleles; one coding for short variety (t) and the other for tall variety (T).