Question

The approximate number of genes contained in the genome of Kalpana Chawla was
A. 40.000
B. 30,000
C. 80,000
D. 1,00,000

Answer 1

Hint: Genome means the complete set of genes of an organism. In human beings, approximately 3 billion DNA base pairs are present.

Complete answer: The genome is defined as an organism’s entire set of DNA which has all the genes required to maintain and sustain.
One genome of an organism has all the information required to build it. In human beings, the genome could also refer to the complete set of DNA sequences, as we know genes are nothing but a group or stretch of some DNA sequences.
Humans have 23 pairs of chromosomes located in the nucleus and there all the genes are present.
According to studies of the Human Genome Project, it was found that our genome has about 3 billion base pairs. It approximately rounds up to 21,000 genes. From the given options, 30,000 is more close to the value.

Additional information: Primary goals of HGP were to discover the complete set of human genes and make them accessible for further biological study, and decode the complete sequence of DNA bases in the human genome.
Benefits of the HGP: One of the future benefits is in the field of molecular medicine.
The benefits in this field could include better diagnosis of some diseases, early detection of diseases, and gene therapy, and control systems for many drugs.

So, the correct option is B. 30,000

Note: There is another term used in these studies called the ‘C-value’. It is constant for a particular species. It refers to the haploid DNA content of a single cell. The human genome has nearly 3 billion base pairs but all of them may not be functioning as genes because of the presence of ‘junk DNA sequences’.