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

Options

A. sexual reproduction is a lengthy process
B. gametes of parents have qualitatively different genetic composition
C. genetic material comes from parents of two different species
D. greater amount of DNA is involved in sexual reproduction.

Explanation

### Step-by-Step Solution:

1. **Understanding Reproduction Types**:
- Sexual reproduction involves the fusion of gametes (sperm and ovum) from two different parents (male and female).
- Asexual reproduction involves a single organism reproducing without the fusion of gametes, resulting in offspring that are genetically identical to the parent.

2. **Genetic Variation in Offspring**:
- In sexual reproduction, offspring inherit a combination of genetic material from both parents. This results in genetic variation due to the mixing of genes.
- In asexual reproduction, the offspring are clones of the parent, meaning they have the same genetic makeup and thus exhibit little to no variation.

3. **Mechanism of Variation**:
- The genetic variation in sexual reproduction arises from processes such as independent assortment and crossing over during meiosis, which shuffle the genetic material.
- In contrast, asexual reproduction does not involve these processes, leading to offspring that are genetically identical to the parent.

4. **Evaluating the Options**:
- The options provided are:
1. Sexual reproduction is a lengthy process.
2. Gametes of parents have qualitatively different genetic composition.
3. Genetic material comes from parents of two different species.
4. Greater amount of DNA is involved in sexual reproduction.
- The correct answer is option 2: "Gametes of parents have qualitatively different genetic composition." This highlights the genetic diversity introduced through the combination of different genetic materials from two parents.

5. **Conclusion**:
- Therefore, offspring formed by sexual reproduction exhibit more variation than those formed by asexual reproduction primarily because they inherit a mix of genetic traits from two different parents, leading to greater genetic diversity.