CB8

Question 1

Oxygen in exchange materials

Answer 1

Cells need it for aerobic respiration - produces co2 as waste
Move by diffusion

Question 2

Water

Answer 2

Taken up by cells by osmosis

In animals, food molecules and mineral ions diffuse with it

Question 3

Urea - what is it?

Answer 3

A waste product made by animals from proteins

Question 4

Urea in exchange of materials

Answer 4

Diffuses from cells to blood plasma fro removal from the body by the kidneys

Question 5

Surface area : volume ratio what is it

Answer 5

How easy it for an organism to exchange substances with its environment

Question 6

The larger an organism is, the smaller

Answer 6

It’s surface area is compared to its volume

Question 7

How do you calculate the surface area?

Answer 7

Surface area = length x width for every side of the shape

Question 8

How do you calculate volume?

Answer 8

Volume = length x width x height

Question 9

How is the alveoli adapted?

Answer 9

A moist lining for dissolving gases
A good supply of blood to maintain the concentration gradients between O2 and CO2
Very thin walls
Big surface area

Question 10

Gas exchange

Answer 10

Blood from body has lots of co2 - maximises conc gradient
O2 diffuses out of the alveoli and into the blood
CO2 diffuses in the opposite direction - breathed out

Question 11

The bigger the difference in the concentration the faster

Answer 11

The diffusion of the substances happen

Question 12

What is the role of red blood cells?

Answer 12

Carry oxygen from lungs to cell in the body

Question 13

How are red blood cells adapted?

Answer 13

Biconcave disc- a disc that is squished in the middle - gives a large surface area to absorb more oxygen
No nucleus - more space for oxygen
Haemoglobin - it binds to oxygen to make oxyhemoglobin

Question 14

White blood cells role

Answer 14

Fight infection

Question 15

Phagocytes - white blood cells

Answer 15

White blood cells that engulf unwelcome micro- organisms

Question 16

Lymphocytes - white blood cells

Answer 16

Produce antibodies and antitoxins to neutralise any toxins produced

Question 17

What are platelets

Answer 17

Cell fragments - no nucleus

Question 18

How do platelets work?

Answer 18

They burst and react with fibrinogen in the plasma and turn it into a mesh of fibrin threads - the mesh traps cells to form a scab

Question 19

What is plasma?

Answer 19

Straw coloured liquid

Question 20

What does plasma carry?

Answer 20

Red and white blood cells and platelets 
Nutrients like glucose + amino acids 
Carbon dioxide 
Urea 
Hormones 
Proteins 
Antibodies and antitoxins

Question 21

Arteries carrying blood

Answer 21

Carry blood away from heart

Question 22

Arteries - blood pressure

Answer 22

Heart pumps blood out at high pressure - artery walls are strong and elastic

Question 23

Arteries lumen

Answer 23

Lumen is narrow - maintain the high blood pressure

- thick layers of muscle + elastic fibres - strong and springs back

Question 24

Capillaries - walls

Answer 24

Once cell thick - increases rate of diffusion

Permeable walls - substances diffuse in and out

Question 25

Veins - blood

Answer 25

Carries blood towards the heart

Question 26

Veins blood pressure

Answer 26

Walls not thick - blood pressure low

Question 27

Veins - large lumen

Answer 27

Helps blood flow

Question 28

Veins - valves

Answer 28

Help blood flowing in the right direction - prevents back flow

Question 29

First circuit of the circulatory system

Answer 29

Heart pumps deoxygenated blood to lungs to take in oxygen

Oxygenated blood returns to heart

Question 30

Second circuit - circulatory system

Answer 30

Heart pumps oxygenated blood around the body

Deoxygenated blood returns to the heart

Question 31

Deoxygenated blood circuit

Answer 31

Heart receives deoxygenated blood from body via the vena cava
Deoxygenated blood moves through right ventricle - pumps the blood to lungs via the pulmonary artery

Question 32

Oxygenated blood circuit

Answer 32

Left atrium receives oxygenated blood from lungs via the pulmonary vein
Oxygenated blood moves to left ventricle- pumps it out round whole body via aorta

Question 33

Which ventricle has more muscle and why?

Answer 33

Left ventricle has thicker walls as it has to pump blood around the whole body at high pressure

Question 34

Cardiac output

Answer 34

Total volume of blood pumped by one ventricle each tune it contracts

Question 35

Heart rate

Answer 35

Number of beats per minute

Question 36

Stroke volume

Answer 36

Volume of blood pumped by one ventricle each time it contracts

Question 37

Cardiac output equation

Answer 37

Cardiac output = heart rate x stroke volume

Question 38

Respiration - what kind of reaction?

Answer 38

The transferring of energy from the breakdown of organic compounds
Energy is transferred into the environment so it is an exothermic reaction

Question 39

Aerobic respiration

Answer 39

Oxygen present

The most efficient way to transfer energy from glucose

Question 40

Aerobic respiration equation

Answer 40

Glucose + oxygen — energy + carbon dioxide + water

Question 41

Anaerobic respiration

Answer 41

Exercise with the absence of oxygen

Transfers less energy so it is less efficient

Question 42

Anaerobic respiration equation

Answer 42

Glucose — lactic acid + energy

Question 43

Anaerobic respiration in plants

Answer 43

Glucose — ethanol + carbon dioxide

Question 44

Investigating respiration method

Answer 44

Add soda lime granules and cotton wool to a test tube - add worm
Set up the respirometer - use syringe to set fluid in manometer
There will be a decrease in volume of air
Liquid in manometer moves towards the tube
The distance can be uses to calculate the volume of oxygen

Question 45

Controls of investigating respiration

Answer 45

Same number of organisms

Each temperature kept consistent - water bath

Question 46

Risks of investigating respiration

Answer 46

Soda lime is corrosive
Treat animals with care
Wash hands after