Natural selection can only occur because of a variety in a population. Natural selection refers to environmental factors that affect a population and causes some of the population to have more surviving offspring than others. An example is a giraffe with a longer neck will be more likely to survive and reproduce (as it can gather more food from taller trees)
Answer:
boiling, freezing, refridgeration, and fertilizer.
Explanation:
the first three have to do with temperature, which tends to kill bacteria. Pesticides kill bacteria by poisoning them
Answer:
Virus.
Explanation:
Viruses can't reproduce without invading the cell of another living being.