Topic 8- Exchange and Transport in Animals

Question 1

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

Answer 1

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

Question 2

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

Answer 2

diffusion

Question 3

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

Answer 3

down

Question 4

For what process in the body do we need oxygen?

Answer 4

aerobic respiration

Question 5

What gases are exchanged in the lungs?

Answer 5

oxygen and carbon dioxide

Question 6

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

Answer 6

haemoglobin

Question 7

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

Answer 7

cm2

Question 8

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

Answer 8

cm3

Question 9

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?

Answer 9

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

Question 10

How are the lungs adapted for efficient gas exchange?

Answer 10

large surface area/alveoli

Question 11

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

Answer 11

oxygen

Question 12

How are alveoli adapted to their function?

Answer 12

they have a large surface area, they have thin walls

Question 13

For what process does the body need glucose?

Answer 13

respiration

Question 14

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

Answer 14

diffusion

Question 15

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

Answer 15

0.6, but accept 3 : 5

Question 16

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

Answer 16

larger cells have a smaller SA : V ratio

Question 17

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

Answer 17

by the flow of blood

Question 18

What is the unit g/cm3 a measure of?

Answer 18

concentration

Question 19

In what other format can g/cm3 be written?

Answer 19

g cm–3

Question 20

Which organ excretes carbon dioxide in humans?

Answer 20

lung(s)

Question 21

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

Answer 21

alveoli

Question 22

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

Answer 22

to increase the rate of diffusion

Question 23

Which organ excretes urea in humans?

Answer 23

kidney(s)

Question 24

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

Answer 24

volume

Question 25

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

Answer 25

smaller

Question 26

Does diffusion happen up or down a concentration gradient?

Answer 26

down

Question 27

What are the smallest blood vessels in the body called?

Answer 27

capillaries

Question 28

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

Answer 28

arteries

Question 29

What is the function of an erythrocyte?

Answer 29

to carry oxygen

Question 30

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

Answer 30

alveoli

Question 31

Which blood vessels take blood away from the heart?

Answer 31

arteries

Question 32

Which blood vessels have thick, elastic walls?

Answer 32

arteries

Question 33

Which blood vessels contain valves?

Answer 33

veins

Question 34

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

Answer 34

capillaries

Question 35

Which blood cells are adapted to carry oxygen?

Answer 35

red blood cells, erythrocytes

Question 36

Which blood cells engulf and digest foreign cells?

Answer 36

phagocytes

Question 37

Which component of the blood carries urea?

Answer 37

plasma

Question 38

What helps to push blood along veins in the legs?

Answer 38

skeletal muscles

Question 39

How many chambers does a human heart have?

Answer 39

four

Question 40

What happens when blood is prevented from reaching heart muscles?

Answer 40

heart attack

Question 41

What are the lower chambers of the heart called?

Answer 41

ventricles

Question 42

What stops blood flowing the wrong way in the heart?

Answer 42

valves

Question 43

Which side of the heart has the thicker muscle walls?

Answer 43

left side

Question 44

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

Answer 44

lungs

Question 45

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

Answer 45

pulmonary vein

Question 46

Does the pulmonary artery carry deoxygenated or oxygenated blood?

Answer 46

deoxygenated

Question 47

Why does heart rate increase during exercise?

Answer 47

cells in tissues need more oxygen/glucose

Question 48

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

Answer 48

0.1 × 50 = 5 litres/min

Question 49

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

Answer 49

oxygen

Question 50

What happens to energy in an exothermic reaction?

Answer 50

It is transferred to the surroundings.