Cell Structures And Funtions C Level

Question 1

State the three main ideas of classical cell theory

Answer 1

All life forms are made of one or more cells.
The cell is the basic unit of life.
New cells come from the division of existing cells.

Question 2

Describe the two main differences between plant and animal cells

Answer 2

Plant cells have cell walls made of cellulose. Animal cells do not.
Plant cells have chloroplast. Animal cells do not.

Question 3

Define passive transport

Answer 3

Passive transport is the movement of substances across the cell membrane that does not require energy from the cell. Substances move from high to low concentration.

Question 4

List and define the three main types of passive transport

Answer 4

Osmosis - the movement of water from an area of high water concentration (low solute concentration) through a selectively permeable cell membrane to an area of low water concentration (high solute concentration).
Diffusion - the movement of atoms or molecules through a cell membrane from an area of higher concentration to an area of lower concentration.
Facilitated diffusion - the movement of atoms or molecules through transport proteins(protein channels or carrier proteins) embedded in the cell membrane.

Question 5

The function of the cell membrane

Answer 5

Separates the interior of the cell from the outside environment. Gives protection and structural support. Functions as a selectively permeable barrier that controls what enters and leaves the cell.

Question 6

Describe the function of the Nucleus

Answer 6

Contains the cell’s DNA and controls the cell’s activities.

Question 7

Describe the function of the cell wall

Answer 7

A layer around the cell membrane that supports and protects cells or plants, algae, fungi and bacteria.

Question 8

Describe the function of the chloroplast

Answer 8

Functions in photosynthesis using light energy to combine molecules of carbon dioxide and water to make complex energy rich carbohydrates (glucose and starch) and release oxygen to the environment.

Question 9

Describe the function of the mitochondrion

Answer 9

Functions in cellular respiration breaking down glucose and other food molecules in the presence of oxygen to form carbon dioxide and water and to release energy as ATP.