Answer:
<h3>Biologists study humans, plants, animals, and the environments in which they live. They may conduct their studies--human medical research, plant research, animal research, environmental system research--at the cellular level or the ecosystem level or anywhere in between.</h3>
Answer:
A unicellular organism is formed by a single cell. ... The circulation in unicellular organisms is carried out by the movement of the cytoplasm of the cell called cyclosis.
<span>(4) active transport
</span>Active transport is the movement of molecules across a cell membrane in the direction against their concentration gradient, i.e. moving from an area of lower concentration to an area of higher concentration.