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Flashcards in Exchange And Transport In Animals Deck (63):
1

Why do cells need oxygen

For aerobic respiration

2

How do oxygen and carbon dioxide move between cells

By diffusion

3

What is urea

A waste product produced by animals from proteins.

4

What does urea do

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

5

How is water taken up by the cells

Osmosis

6

What is SA:V

Surface area to volume ratio

7

What happens to surface area if the organism is large

The surface area is smaller compared to its volume

8

In what cells can substances diffuse directly into a cell across a cell membrane and why

Single-celled organism
It has a large surface area compared to the volume so enough substances can be exchanged across the membrane to supply the volume of the cell

9

Why is it difficult for multicellular organisms to exchange enough substances to supply the entire volume across their outside surface alone

Because they have a smaller surface area compared to their volume

10

What 3 things affect the rate of diffusion and how

Distance
Concentration difference
Surface area

11

How does distance affect the rate of diffusion

Substances diffuse quicker when they haven't as far to move

12

How does concentration difference affect the rate of diffusion

Substances diffuse faster if there's a big difference in concentration between the area they are diffusing from and the area they are diffusing to.

13

How does surface area affect the rate of diffusion

The more surface area there is for molecules to move across to, the faster they can get from one side to the other

14

What is the job of the lungs

To transfer oxygen to the blood and to remove waste carbon dioxide from it

15

What happens in the alveoli

Oxygen diffuses out of the air in the alveoli and into the blood. Carbon dioxide diffuses in the opposite direction to be breathed out

16

How are the alveoli specialised for diffusion

A moist lining for dissolving gases
A good blood supply to maintain the concentration gradients
Very thin walls to minimise the distance the gases move
An enormous surface area

17

How do you calculate rate of diffusion

(Surface area x concentration difference) / thickness of membrane

18

What does Ficks law describe

The rate of diffusion

19

What do red blood cells carry

Oxygen

20

What is the Job of red blood cells

To carry oxygen from the lungs to all the cells in the body

21

Why do red blood cells have a large surface area

To absorb oxygen

22

Why don't red blood cells have a nucleus

So they have more room to carry oxygen

23

What is the red pigment contained by red blood cells

Haemoglobin

24

What happens in the lungs with oxyhemoglobin

Haemoglobin binds with oxygen

25

What happens to oxyhemoglobin in the body tissues

It splits to make haemoglobin and oxygen to release oxygen to the cells

26

What is the main job of white blood cells

To defend against infection

27

What are phagocytes

White blood cells
Change shape to engulf unwelcome microorganisms

28

What are lymphocytes

White blood cells that produce antibodies against microorganisms
Produce antitoxins

29

What do white blood cells do when you have an infection

They multiply to fight it off

30

What do platelets do

Help blood clot so it doesn't pour out and stops microorganisms getting in

31

What are platelets

Small fragments of cells
No nucleus

32

What is plasma

The pale straw coloured liquid that carries everything in blood

33

What does plasma carry

Red & white blood cells
Platelets
CO2
Urea
Nutrients
Hormones
Proteins
Antibodies

34

What do arteries do

Carry blood away from the heart

35

What do veins do

Carry blood to the heart

36

What are capillaries involved in

The exchange of materials at the tissues

37

Why do artery walls need to be strong, thick and elastic

They carry blood away from the heart and that blood is at high pressure

38

Why are capillaries very narrow

So they can squeeze into the gaps between cells
Carry the blood really close to every cell in the body to exchange substances with them

39

What type of walls do capillaries have and why

Permeable walls
So substances can diffuse in and out

40

What do capillaries supply

Food
Oxygen

41

How thick are capillaries

One cell thick

42

Why don't vein walls have to be thick

The blood is at low pressure

43

Why do veins have valves

To keep the blood flowing in the right direction

44

What type of circulatory system do mammals have

A double circulatory system

45

What type of blood is pumped in the first circuit of the heart

Deoxygenated blood

46

What type of blood is pumped in the second circuit

Oxygenated blood

47

How many chambers do our hearts have

4

48

Right atrium:

Receives deoxygenated blood from the body through the vena cava

49

Right ventricle:

The deoxygenated blood moves from the right atrium through it which pumps it to the lungs through the pulmonary artery

50

Left atrium:

Receives oxygenated blood from the lungs via the pulmonary vein

51

Left ventricle:

The oxygenated blood moves from the left atrium to it and then is pumped around the whole body via the aorta

52

Why is the left ventricle thicker than the right ventricle

It needs to pump blood around the whole body at high pressure

53

What do valves do

Prevent the back flow of blood

54

What does the septum do

Separates the two sides of the heart

55

How do you calculate cardiac output

Heart rate x stroke volume

56

What is respiration

The process of transferring energy from the breakdown of organic compounds

57

What is the energy from respiration used for

Metabolic processes
Contracting muscles
Maintaining a steady body temperature

58

What type of reaction is respiration and why

Exothermic
Energy is being transferred to the environment

59

What is the equation for aerobic respiration

Glucose + oxygen ➡️ carbon dioxide + water

60

What does anaerobic mean

Without oxygen

61

What happens in anaerobic respiration

Glucose is partially broken down
Lactic acid is produced

62

What do you use to measure the rate of respiration

A respirometer

63

How do you calculate the rate of reaction

Wood lice are put in the apparatus
They use up the oxygen as they respire
Reduce in pressure
Liquid moves
Different temperatures