B3.1 - Movement Of Molecules In And Out Of Cells

Question 1

What molecules does osmosis apply to?

Answer 1

Water molecules.

Question 2

What do water molecules move across during diffusion?

Answer 2

A partially permeable membrane.

Question 3

What causes osmosis to occur?

Answer 3

A difference in water concentration inside and outside the cell.

Question 4

What do most soft drinks contain? (3)

Answer 4

1. Water.
2. Sugar.
3. Ions.

Question 5

Why do sports drinks contain sugars?

Answer 5

To replace the sugars broken down in energy release during exercise.

Question 6

Why do sports drinks contain water and ions?

Answer 6

To replace the water and ions lost during sweating.

Question 7

What happens if water and ions are not replaced after exercise?

Answer 7

The balance of the body is disturbed and cells are unable to work as efficiently.

Question 8

What are the ways in which dissolved substances can move in and out of cells? (2)

Answer 8

1. Diffusion.

2. Active transport.

Question 9

What are the differences between active transport and diffusion? (2)

Answer 9

1. Active transport goes against the concentration gradient.

2. Active transport requires energy.

Question 10

Where does the energy for active transport come from?

Answer 10

Respiration.

Question 11

What does active transport allow cells to do?

Answer 11

To absorb ions from very dilute solutions.

Question 12

How are exchange surfaces made more effective? (4)

Answer 12

1. A large surface area.
2. Being thin (to provide a short diffusion path).
3. An efficient blood supply.
4. Being ventilated (for gas exchange).

Question 13

What increases the surface area of the lungs?

Answer 13

The alveoli.

Question 14

What increases the surface area of the small intestine?

Answer 14

Villi.

Question 15

What is absorbed by the villi?

Answer 15

The products of digestion.

Question 16

What does the ribcage protect?

Answer 16

The lungs.

Question 17

What is the upper part of the body called?

Answer 17

The thorax.

Question 18

What is the lower part of the body called?

Answer 18

The abdomen.

Question 19

What separates the upper and lower parts of the body?

Answer 19

The diaphragm.

Question 20

What does the breathing system do with gases in the air? (2)

Answer 20

1. Allows oxygen from the air to diffuse into the bloodstream.
2. Allows carbon dioxide to diffuse out of the bloodstream and into the air.

Question 21

What does the thorax do in order to move air into the lungs?

Answer 21

The ribcage moves up and expands, and the diaphragm flattens.

Question 22

What does the thorax do in order to move air out of the lungs?

Answer 22

The rib cage moves downwards and contracts, and the diaphragm is pulled down.

Question 23

How does carbon dioxide enter the leaves?

Answer 23

Diffusion.

Question 24

Where are most of the water and mineral ions absorbed in plants?

Answer 24

The roots.

Question 25

How is the surface area of the roots increased?

Answer 25

Root hairs.

Question 26

How is the surface area of leaves increased? (2)

Answer 26

1. Flattened shape.

2. Internal air spaces.

Question 27

What do the stomata do in gaseous exchange? (2)

Answer 27

1. Obtain carbon dioxide from the atmosphere.

2. Remove oxygen produced in photosynthesis.

Question 28

Where do plants mainly lose water from?

Answer 28

The leaves.

Question 29

In what conditions is evaporation from the leaves most rapid?

Answer 29

Hot, dry and windy conditions.

Question 30

What do the stomata do when the plant is losing more water than it can replace?

Answer 30

Close.

Question 31

Which cells control the size of the stomata?

Answer 31

Guard cells.

Question 32

How do modern ventilators work?

Answer 32

Pumping air into the lungs through a tube.

Question 33

How did an “iron lung” work?

Answer 33

The patient was in a giant case with only their head out, and air was pumped in and out of the case to increase and decrease the pressure.

Question 34

Which method of ventilation interferes with blood flow?

Answer 34

An iron lung.

Question 35

What can be a disadvantage of modern ventilation?

Answer 35

Alveoli can burst.