Which of the following cause(s) variation in the genetic material of progeny? 1. Sexual reproduction 2. Asexual ireproduction 3. Mutations 4. Epigenetic changes Select the correct answer using the code given below.

The correct answer is Option 4 (1 and 3 only) because genetic variation refers to permanent changes in the DNA sequence of an organism's genome.

• Sexual reproduction (1): During meiosis, processes like crossing over and independent assortment reshuffle genetic material, ensuring that the offspring's genotype is distinct from the parents.
• Mutations (3): These are random, permanent alterations in the DNA sequence caused by errors during replication or environmental factors, serving as the primary source of new genetic alleles.
• Asexual reproduction (2): This typically produces clones that are genetically identical to the parent (excluding rare mutations), thus it is not a primary cause of variation.
• Epigenetic changes (4): These involve modifications (like DNA methylation) that affect gene expression rather than the underlying genetic code itself. While they can be heritable, they do not constitute a change in the "genetic material" (DNA sequence).

Therefore, only sexual reproduction and mutations result in actual genetic sequence variation.