UPSC Civil Services Model Paper 7

Genome :
A genome is all the genetic matter in an organism .
It is defined as an organism’s complete set of Deoxyribose Nucleic Acid (DNA), including all of its genes.
Genes contain the information that is required to express a particular trait in an organism.
Hence statement 1 is correct.
Genes are the unit of inheritance.
Genes that code for a pair of contrasting traits are known as alleles , i.e., they are slightly different forms of the same gene .
Every organism’s genetic code is contained in its DNA, the building blocks of life.
Each genome contains all of the information needed to build and maintain that organism.
In humans, a copy of the entire genome contains more than 3 billion DNA base pairs .
DNA:
DNA (Deoxyribonucleic acid) is the hereditary complex molecule present in humans and almost all other organisms.
Nearly every cell in a multicellular organism possesses the full set of DNA required for that organism.
Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix.
The two strands are called polynucleotides since they are composed of simpler monomeric units called nucleotides .
Each nucleotide is composed of one of four chemical bases :
cytosine (C), guanine (G), adenine (A), thymine (T).
It also has a sugar called deoxyribose and a phosphate group.
These nucleotides create proteins that are needed for the cell .
Although 99.9% of human DNA sequences are the same in every person, some of the DNA is unique that makes it possible to distinguish one individual from another.
DNA can be extracted from the saliva, hair, blood samples, any small amount of the muscles or tissues of a person, nail scraping.
DNA’s molecular structure was first identified by James Watson and Francis Crick in 1953 .
Hence statement 2 is correct.
They won the Nobel prize for the same in 1962.