The posterior opening is called the anus
When we talk about evolution we come across the process of natural selection. Genetic variation is always required for the natural selection. A change or variation in the genes may help the individuals in a population to better adapt to the environment. Such changes may be brought by mutations or random mating in the population. Such variations help in the survival of the population by allowing them to adapt to changing environmental conditions.
<span>The mirror is used to focus light through the opening in the in the stage of the microscope.</span>
Seasonal variations of climate impact the state of an ecosystem. In areas that experience a cold season, some elements of the ecosystem change their residence or even hibernate to survive. Succession can be considered a higher state of development of the ecosystem.
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