Answer: Organs are grouped into organ systems, in which they work together to carry out a particular function for the organism. For example, the heart and the blood vessels make up the cardiovascular system.
Answer:
C, distance
Explanation:
Distance and mass are two major factors that affect the strength of the gravitational force.
A nucleus is the control center of a cell.
Answer:
unicellular; multicellular
Explanation:
<em>The smallest and the most basic unit of life is the cell. Living organisms that are made of just one cell are said to be </em><em>unicellular </em><em>while those that are made up of multiple cells are said to be </em><em>multicellular.</em><em> Many unicellular organisms are some of the smallest living organisms to exist in nature. They cannot be seen with the ordinary eyes, except with the aid of microscopes.</em>
