Not all individuals in a population will survive to reproduce. Those that do, pass their___ to their offspring

Not all individuals in a population will survive to reproduce. Those that do, pass their traits to their offspring

Explanation:

Natural selection is an important process of evolution. Nature allows only the fittest to survive. Hence to survive in a particular environment an organism develops special features to adapt to that new environment. When changes happen in the environment variations happen in the genetic materials, a trait so as to survive.

Few organisms perish but few successful traits alone survive. This survived trait develop more adaptability and starts producing generations. This trait is thus passed on to their offspring.

Answer: It's probably traits.

Explanation: They can be passed down.