What are chromosomes and what are three uses of DNA testing in humans?

Here are the answers to question (a):

a)

i) Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made of protein and a single molecule of deoxyribonucleic acid (DNA) tightly coiled many times around proteins called histones that support its structure. They carry genetic information in the form of genes.

ii) Three uses of DNA testing in humans are:

• Paternity testing to determine biological parentage.
• Forensic analysis to identify individuals from crime scene evidence.
• Diagnosis of genetic disorders and predisposition to certain diseases.