B3.1

Question 1

What are the cells, tissues and organs in plants and animals adapted to do

Answer 1

To take up and get rid of dissolved substances

Question 2

What can different conditions affect in cells

Answer 2

The rate of transfer

Question 3

What might be needed sometimes for transfer to take place

Answer 3

Energy

Question 4

How do dissolved substances move

Answer 4

By diffusion or active transport

Question 5

How does water move across boundaries

Answer 5

By osmosis

Question 6

What is osmosis

Answer 6

The diffusion of water from a dilute to a more concentrated solution through a partially permeable membrane that allows the passage of water molecules

Question 7

What do differences in the concentrations of solutions inside and outside a cell cause

Answer 7

Water to move into or out of the cell by osmosis

Question 8

What do most soft drinks contain

Answer 8

Water
Sugar
Ions

Question 9

What does the sugars in sports drinks do

Answer 9

Replace the sugar used in energy release during the activity

Question 10

Why do sport drinks contain water and ions

Answer 10

To replace the water and ions lost during sweating

Question 11

What do sport drinks contain

Answer 11

Water
Ions
Sugars

Question 12

What happens if water and ions are not replaced

Answer 12

The ion/ water balance is disturbed and the cells do not work efficiently

Question 13

What are some substances absorbed against and what does it require

Answer 13

A concentration gradient and requires energy from respiration. This process is called active transport

Question 14

What is active transport

Answer 14

Molecules are moved in and out of a cell using energy

Question 15

When is active transport used

Answer 15

When transport needs to be faster than diffusion

Question 16

What can be transported using active transport

Answer 16

Minerals, glucose and mineral ions

Question 17

What does active transport enable cells to do

Answer 17

To absorb ions from very dilute solution

Question 18

What type of movement is diffusion and why

Answer 18

Passive movement because it requires no energy

Question 19

What are many organs specialised for

Answer 19

Exchanging material

Question 20

How is the effectiveness of an exchange surface increased

Answer 20

By having a large surface area
Being thin so a short diffusion path
(In animals) having an efficient blood supply and being ventilated

Question 21

What increases the difficulty of exchanging materials

Answer 21

The size

Complexity

Question 22

What increases the surface in the small intestine

Answer 22

Villi

Question 23

How does the villi increase the rate of exchange

Answer 23

The epithelial tissue of the villi have micro villi

1 cell thick wall so short diffusion distance

Long network of capillaries so fast absorption

Question 24

What does the lacteal in the villi do

Answer 24

Absorbs fatty acids and glycerol

Question 25

What increases the surface area of the lungs

Answer 25

Alveoli

Question 26

How is the alveoli adapted for gas exchange

Answer 26

1 cell thick- short diffusion distance Lining is moist-easier for gases to exchange Excellent blood supply-faster absorption of O2 or CO2

Question 27

Where is the lungs in the body

Answer 27

Upper part of the body, protected by the ribcage and separated from the lower part if the body by the diaphragm

Question 28

What happens when u inhale

Answer 28

``` Intercostal muscles contract Ribcage lifts up and out Diaphragm contracts Lung volume increases Pressure decreases Air flows into lungs ```

Question 29

What happens when u exhale

Answer 29

``` Intercostal muscles relaxes Ribcage goes down and in Lung volume decreases Pressure increases Air goes out of lung ```

Question 30

Why does the breathing system takes air in and out of the body

Answer 30

So that oxygen from the air can diffuse into the bloodstream and carbon dioxide can diffuse out of the bloodstream

Question 31

What is ventilation

Answer 31

The movement of air into and out of the lungs

Question 32

What are absorbed by the roots

Answer 32

Water and mineral ions

Question 33

How does carbon dioxide leave the plant

Answer 33

By diffusion

Question 34

How is the surface area of roots increased

Answer 34

By root hairs

Question 35

What is the surface area if leaves increased by

Answer 35

The flattened shape Internal air space Thin walls

Question 36

What does the stomata do

Answer 36

To obtain carbon dioxide from the atmosphere and to remove oxygen produced in respiration

Question 37

What process where plants lose water vapour from their leaves

Answer 37

Transpiration

Question 38

Where in cells are water lost

Answer 38

Stomata

Question 39

When is evaporation in plants more rapid

Answer 39

Hot, dry and windy conditions

Question 40

What happens if a plants lose water fast

Answer 40

Replaced by the roots | Stomata can close to stop wilting

Question 41

What is the size of stomata controlled by

Answer 41

Guard cells which surrounds them

Question 42

What is the rate of transpiration

Answer 42

How fast evaporation in the leaves takes place

Question 43

How does light intensity affect the rate of transpiration

Answer 43

It increases so more stomata opens to a point where all the stomata are open

Question 44

Why does light intensity only increase the rate of transpiration only to a certain point

Answer 44

No more stomata can open

Question 45

How does temperature affect the rate of transpiration

Answer 45

The higher the temperature, the faster the water molecules are moving the air so therefore evaporate from leaf quicker

Question 46

How does wind speed affect the rate of transpiration

Answer 46

The faster the water molecules move in the air, The faster water will be removed Diffusion of water out of leaf increases Rate of transpiration increases due to a high concentration gradient

Question 47

How does humidity affect the rate of transpiration

Answer 47

The less humid, the less water in the air Water will diffuse more quickly Increase in rate of transpiration Higher concentration gradient between inside and outside of leaf