Concept:Sexual reproduction creates variation because it combines genetically different gametes from two parents.
Explanation:Gametes are formed through meiosis, which shuffles genes by crossing over and independent assortment.
As a result, each gamete from a parent carries a different genetic composition.
When two such different gametes fuse during fertilisation, the offspring receives new combinations of alleles.
This produces more variation than asexual reproduction, where offspring are genetically identical to the single parent.
Therefore, the key reason is the genetic difference between the gametes of the parents.
Answer:B. gametes of parents have different genetic composition