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.
The second one because they can indicate infection and sickness
Answer:
By doing more research.
Explanation:
The cell theory change with the passage of time by doing more research about the cell. The final modification of the cell theory done by Rudolf Virchow in 1855 on the basis of his new research and findings about the cells. With the passage of time, modification occurs in microscope which enable the scientists to find different parts, organelles and features of cell on the basis of which scientists modify cell theory with the passage of time.
Whatever floats by. sessile animals are stuck in place, and can't move. They're usually aquatic animals. Hope this helps! :)
