Question

How are DNA, chromosomes,genes and alleles related?

Answer 1

Hint: Alleles are the different varieties of the same gene and the chromosome contains both DNA and the genes, which suggests that all these terms are closely related.

Complete answer:
1)The full form of DNA is deoxyribonucleic acid which is formed of polynucleotide chains and is arranged in a double helix and it forms the main genetic material in most organisms and is also responsible for transferring genetic information from parents to offspring.

2)In a particular cell the nucleus contains a pair of a structure known as chromosome which is made up of two chromatids and the chromosome is made up of various proteins and DNA. So we can say that a cell contains chromosomes and that chromosome contains DNA.

3)Gene is a structure that is made up of DNA and is arranged on the chromosome and the alleles are various forms of a gene that are almost similar to each other with little difference in the sequence of DNA. This little difference in the base sequence of the alleles is responsible for various phenotypes observed in an organism.

4)So a cell contains chromosomes and a chromosome contains DNA and gene and alleles are also DNA that lies on the chromosome. From here we can conclude that the main relation between DNA, chromosomes, genes, and alleles is that they all are made up of DNA.

Note: A gene can have multiple alleles but if we consider only a specific location of the gene then only two alleles are present, out of which one is inherited from the mother and the other one is inherited from the father. Also based on the ability of an allele to suppress another allele they are classified as dominant and recessive alleles out of which dominant allele can override the recessive allele or the alleles may also show codominance where all alleles are represented equally.