Answer:
Similarly, drugs, chemicals, temperature, and light are among the external environmental factors that can determine which genes are turned on and off, thereby influencing the way an organism develops and functions... and Squirrels have an important ecological role, especially in forest ecosystems, McCleery said. “Their biggest contribution to the forest is in shaping plant composition. ... When that happens, they are effectively planting seeds,” McCleery said. Over time, this behavior, called caching, changes the composition of a forest also....
Examples of animal behaviors that affect the probability of plant reproduction could include transferring pollen or seeds, and creating conditions for seed germination and growth. ... Examples of genetic factors could include large breed cattle and species of grass affecting growth of organisms.
