In reproduction and heredity, if which mode of reproduction is involved, even greater genetic diversity will be generated in the offspring population?

Introduction / Context:
Genetic diversity is a measure of how many different combinations of genes exist within a population. This diversity is important for evolution, adaptation, and long-term survival of species. Different modes of reproduction affect genetic diversity in different ways. Asexual reproduction usually produces offspring that are genetically very similar to the parent, while sexual reproduction combines genetic material from two parents. This question asks which mode of reproduction, when it occurs, generates greater genetic diversity among offspring.

Given Data / Assumptions:

• Sexual reproduction involves the fusion of male and female gametes.
• Binary fission and vegetative propagation are forms of asexual reproduction.
• Asexual reproduction generally produces offspring almost identical to the parent.
• The question focuses on which process increases diversity most strongly.

Concept / Approach:
In sexual reproduction, offspring receive half of their genetic material from each parent. During meiosis, processes like crossing over and independent assortment shuffle genes, creating new combinations in gametes. When gametes fuse at fertilisation, they form zygotes with unique genetic combinations, leading to high genetic variability in the population. In binary fission, a single-celled organism divides into two cells with identical genetic material, resulting in clones. Asexual reproduction and vegetative propagation in plants likewise produce offspring that are genetically similar or identical to the parent, aside from occasional mutations. Therefore, it is sexual reproduction that greatly increases genetic diversity.

Step-by-Step Solution:
Step 1: Identify that sexual reproduction involves two parents and the fusion of their gametes. Step 2: Recall that during meiosis, chromosome crossing over and independent assortment create many possible gene combinations. Step 3: Understand that fertilisation combines two different sets of genes, further increasing the number of possible genetic combinations in offspring. Step 4: Recognise that binary fission simply copies the DNA and splits one cell into two cells with the same genetic information. Step 5: Note that vegetative propagation and other forms of asexual reproduction produce new individuals with the same genetic makeup as the parent. Step 6: Conclude that sexual reproduction is the mode that generates greater genetic diversity in a population.

Verification / Alternative check:
Biology textbooks emphasise that sexual reproduction increases variation, which is one of the main drivers of evolution by natural selection. They explain how meiosis and fertilisation introduce genetic recombination and new allele combinations. Population genetics models show that sexually reproducing populations tend to have higher levels of genetic variation than clonally reproducing ones. Examples from nature include the wide variety of traits seen in humans and other sexually reproducing animals, compared to near-uniform clones produced by some asexual organisms. These observations confirm that sexual reproduction is strongly linked to greater genetic diversity.

Why Other Options Are Wrong:
Binary fission in which one cell splits into two identical cells is incorrect because it produces genetically identical daughter cells, not diverse offspring.
Asexual reproduction producing genetically identical clones is wrong because its main feature is genetic uniformity rather than diversity, except for rare mutations.
Vegetative propagation using stems, roots, or leaves from one parent plant is a form of asexual reproduction that usually produces clones of the parent plant, not highly diverse offspring.

Common Pitfalls:
Students may mistakenly think that because asexual reproduction can produce many offspring quickly, it must also produce more diversity. However, the number of individuals is different from the variety of genetic combinations. Another pitfall is to overlook the role of meiosis and to think that sexual reproduction only doubles the number of genes, instead of mixing them in new ways. To avoid these errors, remember that diversity comes from mixing and recombination of genetic material, which is precisely what happens in sexual reproduction involving gamete fusion.

Final Answer:
Even greater diversity will be generated if Sexual reproduction involving fusion of gametes from two parents is involved.