# Topic 8- Exchange and Transport in Animals Flashcards Preview

## GCSE Biology - Edexcel > Topic 8- Exchange and Transport in Animals > Flashcards

Flashcards in Topic 8- Exchange and Transport in Animals Deck (50)
1
Q

What do we mean when we talk about the concentration of a substance?

A

the amount of the substance in a certain volume (usually of another substance)

2
Q

By what process do particles move from a place of greater concentration to a place of lower concentration?

A

diffusion

3
Q

In diffusion, do particles move up or down a concentration gradient?

A

down

4
Q

For what process in the body do we need oxygen?

A

aerobic respiration

5
Q

What gases are exchanged in the lungs?

A

oxygen and carbon dioxide

6
Q

What molecule is used to carry oxygen in red blood cells?

A

haemoglobin

7
Q

A cuboid has sides of 4 cm by 4 cm by 5 cm. What units would be used for its surface area?

A

cm2

8
Q

A cuboid has sides of 4 cm by 4 cm by 5 cm. What units would be used for its volume?

A

cm3

9
Q

A cell has a surface area of 24 cm2 and a volume of 8 cm3. What is the ratio of its surface area to its volume?

A

3 : 1, although note that surface area : volume (SA : V) ratios are given as a single figure, 31 3  in this case

10
Q

How are the lungs adapted for efficient gas exchange?

A

large surface area/alveoli

11
Q

In human lungs, what gas is transported into the blood using gas exchange?

A

oxygen

12
Q

How are alveoli adapted to their function?

A

they have a large surface area, they have thin walls

13
Q

For what process does the body need glucose?

A

respiration

14
Q

By what transport method do carbon dioxide molecules move from the blood into the lungs?

A

diffusion

15
Q

A cube has a volume of 1000 cm3 and surface area of 600 cm2. What is its surface area : volume ratio?

A

0.6, but accept 3 : 5

16
Q

How is the SA : V ratio of larger cells different from the SA : V ratio of smaller cells?

A

larger cells have a smaller SA : V ratio

17
Q

How is the concentration gradient of oxygen between the inside and the outside of a capillary maintained?

A

by the flow of blood

18
Q

What is the unit g/cm3 a measure of?

A

concentration

19
Q

In what other format can g/cm3 be written?

A

g cm–3

20
Q

Which organ excretes carbon dioxide in humans?

A

lung(s)

21
Q

In what pocket-shaped structures does carbon dioxide excretion occur?

A

alveoli

22
Q

Why do alveoli have walls that are only one cell thick?

A

to increase the rate of diffusion

23
Q

Which organ excretes urea in humans?

A

kidney(s)

24
Q

What do you divide surface area by to calculate a surface area : volume (SA : V) ratio?

A

volume

25
Q

Which have the bigger SA : V ratios, smaller cells or larger cells?

A

smaller

26
Q

Does diffusion happen up or down a concentration gradient?

A

down

27
Q

What are the smallest blood vessels in the body called?

A

capillaries

28
Q

What is the name of the blood vessels that carry blood away from the heart?

A

arteries

29
Q

What is the function of an erythrocyte?

A

to carry oxygen

30
Q

What is the name of the ‘pockets’ in the lungs where gas exchange occurs?

A

alveoli

31
Q

Which blood vessels take blood away from the heart?

A

arteries

32
Q

Which blood vessels have thick, elastic walls?

A

arteries

33
Q

Which blood vessels contain valves?

A

veins

34
Q

Through which blood vessels does diffusion of substances into and out of tissues take place?

A

capillaries

35
Q

Which blood cells are adapted to carry oxygen?

A

red blood cells, erythrocytes

36
Q

Which blood cells engulf and digest foreign cells?

A

phagocytes

37
Q

Which component of the blood carries urea?

A

plasma

38
Q

What helps to push blood along veins in the legs?

A

skeletal muscles

39
Q

How many chambers does a human heart have?

A

four

40
Q

What happens when blood is prevented from reaching heart muscles?

A

heart attack

41
Q

What are the lower chambers of the heart called?

A

ventricles

42
Q

What stops blood flowing the wrong way in the heart?

A

valves

43
Q

Which side of the heart has the thicker muscle walls?

A

left side

44
Q

What parts of the body does the right side of the heart supply with blood?

A

lungs

45
Q

Which blood vessel carries blood to the left atrium from the lungs?

A

pulmonary vein

46
Q

Does the pulmonary artery carry deoxygenated or oxygenated blood?

A

deoxygenated

47
Q

Why does heart rate increase during exercise?

A

cells in tissues need more oxygen/glucose

48
Q

Jack’s stroke volume is 0.1 litres/beat and his heart rate is 50 beats per minute. What is his cardiac output?

A

0.1 × 50 = 5 litres/min

49
Q

What element does aerobic respiration need that anaerobic respiration does not?

A

oxygen

50
Q

What happens to energy in an exothermic reaction?

A

It is transferred to the surroundings.