Mutations can be transmitted to the next generation only if they are present in

The germline (the gametes)

Explanation:

Mutations are permanent changes in the DNA sequence. They can occur randomly, from mistakes during DNA replication, or as the result of external factors like UV radiation.

For these mutations to be passed on to the next generation, they must be present in the DNA of the gametes (i. e. the egg and sperm cells). This is because this is the DNA that goes on to make the offspring in the next generation following fertilisation.

If mutations are present in somatic cells (i. e. cells other than the gametes), they are not passed on to the next generation. For example, if someone gets mutations in their skin cells as a result of exposure to UV rays, this will not be passed on to their children.