Q.Which is a better mode of reproduction: sexual or asexual? Why?

Asexual reproduction produces offspring that are genetically identical to the single parent (clones), through mitotic division alone, with no fusion of gametes. Sexual reproduction, in contrast, involves meiosis (which shuffles genes through crossing over and independent assortment) and the fusion of two gametes from (usually) two different parents, producing offspring that are genetically variable and different from both parents and from each other.

Both modes of reproduction have advantages, but they serve different purposes:

Asexual reproduction

• Involves a single parent; new individuals are produced by mitotic division of body cells (e.g., budding in yeast/Hydra, fragmentation, vegetative propagation).
• Offspring are genetically identical to the parent (clones).
• Advantage: it is rapid, does not require finding/attracting a mate, and is efficient in a stable, unchanging environment where the parent's genotype is already well-suited.
• Disadvantage: because all offspring are genetically identical, the population has little or no genetic variation. If the environment changes (new disease, climate shift, new predator), the entire population may be equally vulnerable and could be wiped out.

Sexual reproduction

• Involves formation of haploid gametes by meiosis (in two parents, or within the same individual in some plants/animals) followed by fertilisation (fusion of male and female gametes) to restore the diploid number.
• Meiosis introduces variation through crossing over and independent assortment of chromosomes; fertilisation further combines genes from two different individuals.
• Offspring are therefore genetically variable — different from each other and from their parents.
• Advantage: this variation is the raw material for natural selection. In a population with variation, some individuals are more likely to survive and reproduce when the environment changes, giving the species better long-term adaptability and evolutionary potential.
• Disadvantage: it is more complex, slower, energy-consuming, and requires two parents/gamete compatibility.

Conclusion: In terms of long-term survival and adaptability of a species in a changing world, sexual reproduction is considered the better/superior mode because of the genetic variation it creates. However, asexual reproduction remains advantageous for quick colonisation and reproduction in stable environments — so the 'better' mode depends partly on context, but sexual reproduction is favoured evolutionarily by most complex/higher organisms.

Compare the two on (1) number of parents and process (mitosis vs meiosis + fertilisation), (2) genetic outcome (identical clones vs variable offspring), and (3) evolutionary consequence (no adaptability vs raw material for natural selection) to conclude sexual reproduction is favoured long-term.

• Declaring one mode 'better' without explaining WHY (the variation-and-adaptability argument) — the reasoning is the actual answer, not just the verdict.
• Ignoring that asexual reproduction does have real advantages (speed, no mate needed, useful in stable environments) — a one-sided answer misses nuance the NCERT expects.
• Mixing up mitosis and meiosis, or forgetting that variation arises specifically from meiosis (crossing over/independent assortment) and fertilisation.