Why do you think digestion is more eficient if your sitting up, rather than slumped over or lying down

Which of the following occurs most often in a population when genetic variation and overproduction are present? some organisms have a lower reproductive success than others. some organisms have a higher reproductive success than others. some organisms have no reproductive success. some organisms do not have genetic variation.

Chloroplasts and bacteria are in size. a. similar b. at different ends of the size range c. exactly the same d. none of these

Everything in the universe originated from a single point. how was it possible for everything in the universe to have occupied a single point in space?