Biology Spl

You have several choices such as a Bachelors degree in physics, chemistry or biology. Also, explore your interest and check if you would be interested to do a Bachelors degree in any of the following:
Psychology
Biodiversity
Biochemistry
Molecular Biology
Bachelors of Health Sciences
Bachelors of Nursing
B.Pharma
B.Sc in Agriculture and so on.

A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins. In humans, genes vary in size from a few hundred DNA bases to more than 2 million bases. The Human Genome Project has estimated that humans have between 20,000 and 25,000 genes.
To know about it's structure, refer to the link below:
https://ghr.nlm.nih.gov/primer/basics/gene

Dear Mr. Chandra Sekhar,
Since, you are already aware of your weakness, my recommendation would be to first work to improve this aspect before taking the CAT. In recent years, weightage to the verbal and reading comprehension section has increased indicating that the examiners are really looking for good communication skills-both verbal and non-verbal.
If you do manage to score well in the CAT, selection to any B-school would require you to clear a rigorous interview or group discussion round. These would need not just average but fantastic communication skills. So, take a wise decision and not a hasty one.
All the best.