I believe hypothesis .
Please vote my answer brainliest. thanks!
Insertion
Genetic stability maintenance requires an extremely accurate mechanism for DNA replication and mechanisms for fixing the several accidental lesions that occur continually in DNA. Spontaneous changes in DNA are temporary due to immediate correction process called DNA repair. DNA repair’s importance is very evident from the huge investment that cells form in DNA repair enzymes. In 1000 accidental base changes in DNA , fewer than one results in a permanent mutation due to the efficient elimination by the DNA repair.<span> </span>
Any characteristic, whether a physical trait, a behaviour, a physiological adaptation etc can make an organism more or less likely to survive in a particular environment.
A dark colour could help a rabbit survive if it lives in a dark forest, because predators can't see it so well, but it would be less likely to survive in the arctic, where the environment is all white and it would show up.
In terms of the characteristics, think about: does it help the organism get food? Does it help protect the organism from predators? If it does, that organism is more likely to survive, and pass the characteristic on to it's offspring. If a bacterium has a characteristic of not being killed by antibiotics, this will help it to survive and breed.