Which of the following should the students add more of to help remove nitrates and improve the natural cycling of nitrogen in this aquarium

Suppose a scientist measures the amount of dna per cell of a particular diploid species at various stages of meiosis. she finds that the meiotic cells contain 3.7 pg , 7.3 pg , or 14.6 pg of dna. match each stage of the cell cycle to the corresponding amount of dna contained within a cell at that stage.

Some plants have reproductive structures that them reproduce using natural forces or animals. how does the reproductive structure shown here ensure the reproductive success of plants?

The united states uses which source of energy to produce almost 40 percent of its electricity