Offspring formed by sexual reproduction exhibit more variation than those formed by asexual reproduction because

Step 1: Analyze the question We are asked why sexual reproduction produces more variation among offspring than asexual reproduction.

Step 2: Explain the concept

• Asexual reproduction involves only one parent and mitosis. The offspring are genetically identical to the parent (clones), apart from rare mutations.
• Sexual reproduction involves two parents, each contributing a gamete (sperm or egg, pollen or ovule). Gametes are made by meiosis, which shuffles genes through: • Crossing over, where chromosomes exchange segments. • Independent assortment, where chromosomes are distributed randomly into gametes. • Random fertilisation, where any sperm can fuse with any egg.

As a result, each gamete has a different genetic makeup, and the offspring get a new combination of genes from both parents.

Step 3: Evaluate the options

• A. Greater amount of DNA is involved. Wrong. Offspring have the same amount of DNA as the parents (the chromosome number is restored at fertilisation). The amount of DNA is not what causes variation.
• B. Gametes of parents have different genetic composition. Correct. Gametes from the two parents carry different gene combinations, so their fusion produces new combinations in the offspring.
• C. Genetic materials come from parents of two different species. Wrong. Sexual reproduction normally occurs within the same species. Parents of different species rarely produce fertile offspring.
• D. Sexual reproduction is a lengthy process. Wrong. The time taken has no effect on genetic variation.

Step 4: Answer The correct option is B.

Exam tip: Remember "sexual = shuffle and mix". Whenever a question asks about variation, look for words like gametes, meiosis, crossing over, fertilisation or two parents. For asexual reproduction, think "one parent, mitosis, clones".