October PPE

Question 1

What is diffusion?

Answer 1

The movement of molecules from an area of a higher concentration to an area of lower concentration.

Question 2

Two things in diffusion that happens to particles:

Answer 2

• They will move in both directions but overall they will move from high to low concentration
• They will end up spread evenly through the liquid or gas but will continue to move

Question 3

Example of diffusion in biology:

Answer 3

• In a leaf
• The lungs

Question 4

How does diffusion happen in a leaf?

Answer 4

Oxygen moves out of cells by diffusion and Carbon dioxide moves into cells but diffusion

Question 5

How diffusion happen in the lungs?

Answer 5

Blood flows in capillary, there’s a high concentration of carbon dioxide and a low concentration of oxygen. The CO2 diffuses from a high concentration in the blood to a low concentration in alveoli

Question 6

What is Osmosis?

Answer 6

It is the movement of water molecules on only! The diffusion of water molecules from a region where the water molecules are in high concentration ➡️ lower concentration through a PARTIALLY PERMEABLE MEMBRANE

Question 7

An example of osmosis:

Answer 7

-Plant Cells - root hair cells take up water by osmosis
-Animal cells - will change size and shape as they take on water

Question 8

What is Active Transport?

Answer 8

It is the process required to move molecules against the concentration gradient. E.G low to high

Requires energy!!!

Question 9

Active Transport in Plants

Answer 9

Plants to take up mineral ions into root hair e.g nitrate has a low concentration in the soil and has to get into the plant

Question 10

Active Transport in Animals

Answer 10

Glucose in the gut needs to be absorbed. Movement of Glucose involves active transport, this requires energy=aerobic respiration