2g - Gas Exchange

Question 1

What does the net exchange of gases depend on?

Answer 1

Light Intensity

Question 2

During the day, do plants make more or less oxygen than they use in respiration?

Answer 2

More

Question 3

During the day, do plants use up more or less CO2 than they produce?

Answer 3

More

Question 4

At night do plants take in o2 or release it?

Answer 4

Take it in for respiration

Question 5

Why is leaves being broad an advantage?

Answer 5

So they have a large surface area for diffusion

Question 6

Why is leaves being thin an advantage?

Answer 6

So there is short diffusion pathway for the gases

Question 7

During the day are the stomata open or close?

Answer 7

Open to allow CO2 in for photosynthesis

Question 8

During the day, do the stomata let water in or out?

Answer 8

Out

Question 9

At night are the stomata open or closed?

Answer 9

Closed to stop water loss (don’t need to let co2 in)

Question 10

What happens to guard cells as they open the stomata?

Answer 10

They increase in volume

Question 11

What happens to guard cells as they close the stomata?

Answer 11

They decrease in volume

Question 12

What colour is hydrogen carbonate indicator in high co2 levels?

Answer 12

Yellow

Question 13

What colour is hydrogen carbonate indicator in low co2 levels?

Answer 13

Purple

Question 14

What colour is hydrogen carbonate indicator in normal CO2 levels?

Answer 14

Red

Question 15

What’s the function of the ribs?

Answer 15

protects internal organs such as the lungs

Question 16

What’s the function of the intercostal muscles?

Answer 16

control the movement of ribs - causing inhalation and exhalation

Question 17

What’s the function of the diaphragm?

Answer 17

Helps change the volume of the thorax

Question 18

What’s the function of the trachea

Answer 18

Windpipe that connects the mouth and nose to the lung

Question 19

What’s the function of the alveoli?

Answer 19

Tiny air sacs where gas exchange take place

Question 20

What’s the function of the pleural membranes ?

Answer 20

Lubricates the lungs to reduce friction

Question 21

Describing breathing IN:

Answer 21

• intercostal muscles + diaphragm CONTRACT
• rib cage moves UP and OUT
• Thorax INCREASES
• Pressure DECREASES
• Air is drawn IN to lungs

Question 22

Describe breathing OUT:

Answer 22

• intercostal muscles + diaphragm RELAX
• rib cage moves DOWN and IN
• Thorax DECREASES
• Pressure INCREASES
• Air is drawn OUT of lungs

Question 23

How are alveoli adapted for gas exchange?

Answer 23

• large surface area
• thin walls
• moist
• good blood supply
• permeable