<h3><u>Answer;</u></h3>
<u>The second part of the cell theory</u> which states that the cells are the basic units or the smallest units of living things.
<h3><u>Explanation</u>;</h3>
- <em><u>Cell Theory is the basic theory of biology that describes one of the major characteristics of life. All living things have cells.</u></em>
- The first part of The Cell Theory states that all living things are made of cells.
- <u>The second part of the cell theory states that cells are the basic units or the smallest units and function of living things.</u>
- The third part or the third statement of The Cell Theory states that the cells only come from or originates from living cells.
It means that they are not like pre-set blueprints. They react differently according to changes in the environment.<span />
The correct answer is A.
Animal cells do not have a cell wall.
A cell wall is the rigid, outermost covering of plant cells and is made up of cellulose. It is absent in animal cells. The cell wall is visible under a light microscope.
Animal cells are instead covered by a cell membrane. It is made up of lipids, proteins, and small amounts carbohydrates. It is a thin and delicate structure that can only be seen using an electron microscope.
Exothermic reactions lose heat and are hot to the touch (Think explosion)
Endothermic reactions gain heat and are cold to the touch (Think of an instant ice pack where you pop it to make it cold)
Water molecules can pass through the cell's membrane because can be used to regulate the cell activity