B3.1 Exchange of Materials

Question 1

What is Osmosis?

Answer 1

Diffusion of water across a partially permeable membrane

Question 2

The water moves from a region of high…

Answer 2

…concentration to low concentration (Dilute to more concentrated)

Question 3

Does osmosis require energy?

Answer 3

No, Osmosis does not require energy.

Question 4

What does active transport allow cells to do?

Answer 4

Take in substances against the concentration gradient.

Question 5

Why does Active transport require energy?

Answer 5

Because it needs to transport the substance against a concentration gradient.

Question 6

Where does active transport get the energy needed?

Answer 6

In respiration

Question 7

What sugar is used in respiration?

Answer 7

Glucose

Question 8

What can happen when you sweat a lot?

Answer 8

Your body cells become dehydrated

Question 9

What do you need to replace if you exercise for a long time?

Answer 9

Sugar, mineral ions and water.

Question 10

How a mineral ions lost during exercise?

Answer 10

Mineral ions are lost through sweat

Question 11

what is a solute?

Answer 11

a soluble food molecule

Question 12

What do efficient exchange surfaces have?

Answer 12

Large surface areas, thin walls, and an effective transport system

Question 13

give an example of an efficient transport system.

Answer 13

The blood supply in humans

Question 14

What structures increase the surface area of the lungs?

Answer 14

Alveoli (air sacs)

Question 15

Where does oxygen diffuse into and out of?

Answer 15

Into the capillaries surrounding the alveoli, then CO2 out into the lungs to be breathed out.

Question 16

Where are the lungs situated?

Answer 16

Inside the ribcage and above the diaphragm

Question 17

what happens when we breath in?

Answer 17

• Intercostal muscles contract
• Ribcage moves up and out
• volume of the thorax increases
• pressure is decreased, drawing in air

Question 18

what happens when we breath out?

Answer 18

• Intercostal muscles relax
• diaphragm becomes domed
• thorax volume decreases
• pressure increases, forcing air out.

Question 19

what is ventilation?

Answer 19

movement of air in and out of the lungs.

Question 20

Why might someone not be able to get enough oxygen into their bloodstream?

Answer 20

• Damaged alveoli

- Person is paralysed

Question 21

advantages of positive pressure over iron lung?

Answer 21

Smaller, easier to manage.

Question 22

what do the villi do?

Answer 22

Act as an efficient exchange surface for absorbing soluble products of digestion

Question 23

How are the villi efficient exchange surfaces?

Answer 23

They provide a large surface area and have a good blood supply