Question

“Stability of DNA in a species is ensured during sexual reproduction.” Justify the statement.

Answer 1

Step 1: Understand what DNA stability means
DNA (Deoxyribonucleic Acid) is the hereditary material that carries genetic information in living organisms. Stability of DNA means that its structure and information remain intact and are accurately passed from one generation to the next.

Step 2: Role of sexual reproduction in ensuring DNA stability
- In sexual reproduction, genetic material comes from two parents through specialized cells called gametes (sperm and egg).
- These gametes are formed by a process called meiosis, which ensures that each gamete contains half the number of chromosomes.
- During fertilization, the chromosomes from both parents combine, restoring the original chromosome number of the species and maintaining DNA content.

Step 3: Mechanisms that ensure stability
- Accurate DNA replication: DNA copies itself with high precision during cell division to maintain genetic consistency.
- Recombination and regulated mixing: While genetic recombination during meiosis introduces variation, it also follows a controlled process that avoids harmful changes to the DNA structure.

Step 4: Conclusion
Sexual reproduction ensures the stability of DNA across generations by preserving the amount of genetic material and passing it through a well-organized system of gamete formation and fertilization.

Final Answer:
Stability of DNA in a species is ensured during sexual reproduction because of accurate DNA replication, maintenance of chromosome number, and controlled genetic recombination during gamete formation and fertilization.