Question

Identify the correct order of organisation of genetic material from largest to smallest.
A. Chromosome, Genome, Nucleotide, Gene.
B. Chromosome, Gene, Genome, Nucleotide.
C. Genome, Chromosome, Nucleotide, Gene.
D. Genome, Chromosome, Gene, Nucleotide.

Answer 1

Hint: Genetic material refers to the material found in the nucleus, cytoplasm and mitochondria which play an important role in determining the structure and also the nature of cell substances.

Complete answer:
First of all, you should know what genetic material is. Genetic material refers to that material which carries genetic information and this genetic information passes from one generation to the next. There are four genetic materials given in the options i.e.,
Genome: A genome is a complete set of DNA which includes all of its genes and the non-coding DNA as well as mitochondrial DNA and chloroplast DNA. It is required to contain all the information which is needed in order to build and maintain that organism. It is largest from all the given options.
Chromosome: These are threadlike structures made up of protein and a single molecule of DNA which is located inside the nucleus of animal and plant cells. Its main function is to fit the DNA inside the nucleus and a chromosome contains hundreds to thousands of genes which make organisms what they are. Its organisation comes after the genome as the genome is the largest.
Gene: Genes are the basic physical and functional unit of heredity and these are DNA regions which tell cells how to make proteins. These are present on chromosomes and genes are passed from parents to offspring containing the information needed to specify traits. Its organisation comes after chromosomes as chromosomes contain the genes.
Nucleotides: These are the building blocks of nucleic acids which serve as monomeric units of the nucleic acid polymers deoxyribonucleic acid and ribonucleic acid. Both of these are essential bio molecules within all life-forms on Earth. Nucleotides come after genes.
From the above explanation it is clear that the series of organisation of genetic material from largest to smallest is Genome, Chromosome, Gene, Nucleotide which is given in the option D.
Thus, the correct answer is option D i.e., Genome, Chromosome, Gene, Nucleotide.

Note: Since the genome consists of a complete set of DNA, it is the largest from all the given options and then chromosomes come which is a threadlike structure carrying thousands of genes and then genes come as these are present on chromosome which means they are smaller than chromosomes. Then the smallest one is nucleotides which are building blocks of nucleic acid.