What alternate form of genes do nucleic acids have that allows them to offer variability allele codon nucleotide chromosome

The options to this question are:

A) allele

B) codon

C) nucleotide

D) chromosome

The answer is A) allele

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).

they have identical fossils of organisms that have evolved over time.

both have animal fossils preserved in them due to weathering and erosion.

they contain different fossils because life on earth has changed through time.

the fossils in them were formed on the surface of earth due to exposure to sunlight.