Respiration and gas exchange

Question 1

What can you use to detect CO2?

Answer 1

Hydrogen carbonate indicator

Question 2

How does Hydrogen Carbonate indicator change?

Answer 2

Orange in normal CO2 concentration

Yellow when CO2 concentration increases

Purple when CO2 concentration decreases

Question 3

An experiment to demonstrate carbon dioxide production by beans

Answer 3

Put dead beans and germinating beans in tubes, and see that only the germinating beans produce CO2

The germinating beans will also produce more heat

Question 4

How do plants exchange gasses (CO2 and oxygen)?

Answer 4

Diffusion, different concentration gradients

Question 5

Why does the net exchange of gases in plants rely on light intensity?

Answer 5

Photosynthesis only happens when there’s light available (day), but plants need to respire day and night to live

So at day they make more oxygen by photosynthesis than they use up in respiration. So at day they release oxygen, as well as taking in more CO2

At night they only respire, so they give out CO2 and take in oxygen

Question 6

How are leaves adapted for efficient gas exchange?

Answer 6

Broad leaves, higher surface area for diffusion

Thin leaves, decreases time for diffusion of gases

Air spaces in leaf, increases surface area and allows gasses to move easier between cells

Stomata allow gases to diffuse in and out, stop letting water out at night to prevent dehydration, controlled by guard cells

Question 7

Test to see how light intensity effects CO2 production?

Answer 7

Put leaves which have been exposed to different light intensities with hydrogen carbonate indicator, the more light they are exposed to the less CO2 produced

Question 8

Structure of the lungs?

Answer 8

P32

Question 9

What’s the thorax?

Answer 9

Top part of your body, separated by diapraghm

Question 10

What does the ribcage do?

Answer 10

Protect lungs

Question 11

What does air we initially breath go through?

Answer 11

Trachea

Question 12

What does the trachea split into two?

Answer 12

Bronchi

Question 13

After they are in the lungs, what do the Bronchi split in to?

Answer 13

Bronchioles

Question 14

What do the Bronchioles split in to?

Answer 14

Alveoli

Question 15

What happens when you breathe in?

Answer 15

Intercostal muscles and diaphragm contract

Thorax volume increases

Pressure decreased drawing air in

Question 16

What happens when you breathe out?

Answer 16

Intercostal muscles and diaphragm relax

Thorax volume decreases

Pressure increased forcing air out

Question 17

What happens the more you exercise?

Answer 17

Breathing rate increases, to take in more oxygen for muscles and remove CO2

Question 18

What happens at the alveoli?

Answer 18

The oxygen diffuses into the blood, which has a low concentration of CO2 after being to the rest of the body. The CO2 is breathed out

Question 19

What happens when the blood reaches the body cells?

Answer 19

Oxygen diffuses into cells, CO2 diffuses into blood

Question 20

How are alveoli adapted for gas exchange?

Answer 20

Lots of microscopic alveoli give it a big surface area

Moist lining for gases to diffuse

Thin walls for diffusion

Good blood supply

Walls are permeable

Question 21

Problems of smoking tobacco?

Answer 21

Reduces size of alveoli, causing emphysema

Tar damages cilia (Hairs on lungs), causing chest infections

Tar irritates bronchi, causing smokers cough and chronic bronchitis

Contains Carcinogens which lead to cancer

Carbon monoxide, reduces the amount of CO2 blood can hold, increasing heart rate, increasing bood pressure, damaging atery walls, increasing chance of blood clots which lead to Coronary heart disease