Which is responsible for variation in the offspring ?

sexual reproduction

The correct answer is Option (3) - sexual reproduction

Primarily, sexual reproduction is responsible for variation in offspring. This is because sexual reproduction involves the mixing of genetic material from two parents.

• Meiosis:

• During meiosis, the sex cells (egg and sperm) divide and shuffle the genetic material from the organism. This shuffling creates new combinations of genes that are not present in either parent.
• Fertilization: When fertilization occurs, the sperm and egg fuse to form a zygote. The zygote contains a unique combination of genes from both parents. This combination can lead to offspring with traits that are different from either parent.

Asexual reproduction, on the other hand, typically results in offspring that are genetically identical to the parent organism. However, there can be some variation in offspring produced by asexual reproduction due to mutations.

• Mutations: Mutations are changes in the DNA of an organism. Mutations can be caused by errors in DNA replication, exposure to environmental toxins, or radiation. Mutations can lead to new traits in offspring.

In conclusion, sexual reproduction is the primary mechanism for variation in offspring, while mutations can also play a role in asexual reproduction.