The correct response that results in genetic variation in body cells is mutations caused by environmental factors.
While meiosis and crossing over are processes that primarily contribute to genetic variation in gametes (sperm and egg cells), mutations can affect body cells (somatic cells) as well. These mutations can occur due to environmental influences (like radiation or chemicals) and lead to genetic variation in those body cells.
To clarify:
- Meiosis is a process of cell division that produces gametes, leading to genetic diversity in offspring.
- Crossing over occurs during meiosis and enhances genetic variation in gametes.
- Errors during gamete DNA replication can produce variations in gametes but primarily affect reproductive cells.
Therefore, the best choice among the options given for genetic variation specifically in body cells is mutations caused by environmental factors.