Transport

Question 1

Describe how the structure of a fish heart differs from that of a human heart

Answer 1

1) The fish has 2 chambers whereas the human has 4
2) The fish heart has fewer valves than the human heart
3) The fish heart has no septum whereas the human heart does

Question 2

Explain the difference in concentration of gases

Answer 2

1) Blood leaving the fish heart has more carbon dioxide and less oxygen than blood leaving the human heart
2) This is because the fish body cells have used it up for respiration
3) And the carbon dioxide has been produced as a result
4) The blood leaving the human heart has already been to the lungs, where carbon dioxide is absorbed

Question 3

Why is the pressure of the blood returning to the fish heart lower than the pressure of the blood returning to the human heart?

Answer 3

1) Fish have single circulation/no separate circulation
2) Therefore, the blood in a fish has to pass through 2 sets of capillaries
3) Fish have a smaller heart

Question 4

3 differences between veins and arteries

Answer 4

1) Veins have much less muscle than arteries
2) Veins have a wide lumen whereas arteries have a narrow lumen
3) Arteries have no valves

Question 5

Name 2 substances that are transported in the xylem

Answer 5

Water and ions/salts

Question 6

How does blood change when it is in the lungs?

Answer 6

1) Loses carbon dioxide

2) Gains oxygen

Question 7

What is the purpose of the tricuspid valve?

Answer 7

Prevents backflow of blood

Question 8

How does having more red blood cells benefit athletes in long distance races? (altitude)

Answer 8

1) Training at a high altitude will increases the amount of hemoglobin in the blood
2) This means more oxygen can be transported and absorbed to the muscles
3) Therefore, they can respire aerobically more
4) Releasing more energy
5) There will also be less anaerobic respiration taking place which prevents the build up of lactic acid in the muscles
6) This means the athlete can run further without getting tired

Question 9

Role of Stomata in transport in plants

Answer 9

1) Allows transpiration of water

2) Roots therefore absorb more water to account for this change

Question 10

Role of Stomata in gas exchange in plants

Answer 10

1) Guard cells control the entry/exit of carbon dioxide
2) This happens via diffusion
3) Used for photosynthesis

Question 11

Explain the effect that moving air has on transpiration rate

Answer 11

1) Carries water molecules away from the plant quicker
2) This increases the concentration gradient (of water molecules)
3) Meaning diffusion happens more quickly

Question 12

Why does heart rate increase right before exercise

Answer 12

1) Adrenaline is produced in anticipation of exercise

2) This causes the heart to beat faster

Question 13

How has a low heart rate developed in cyclists and long-distance runners?

Answer 13

1) The exercise frequently
2) So have more muscular hearts
3) Meaning they can pump more blood with each beat
4) Needs to pump less to deliver the same amount of oxygen

Question 14

Difference in the structure of left ventricle vs. the right ventricle

Answer 14

1) The left ventricle wall consists of thicker muscle than the right ventricle
2) This is because it has to create greater pressure in the blood being pumped out of it
3) As it is pumping the blood around the body

Question 15

How does having a hole between the right and left ventricle effect a baby

Answer 15

1) Oxygenated and deoxygenated blood mix
2) This causes the efficiency of aerobic respiration to decrease
3) The baby produces less energy and its growth may therefore be stunted

Question 16

How to measure heart rate

Answer 16

Put her thumb on top of the veins in her neck/wrist and count the number of pulses in a minute

Question 17

Why do scientists obtain blood samples from a vein rather than an artery?

Answer 17

1) Veins have a thinner wall so are easier to puncture

2) Veins are closer to the skin so can easily be reached with a syringe

Question 18

Why can scientists not obtain blood samples from capillaries?

Answer 18

They are much too small

Question 19

Why does blood clot in a stationary leg?

Answer 19

1) Lack of muscle contractions

2) Mean the vein is not squeezed

Question 20

Name the apparatus Steven used

Answer 20

Potometer

Question 21

How should Steven set up the apparatus and use it to estimate transpiration rate in the plant?

Answer 21

1) Cut the shoot underwater
2) Take the capillary tube out of the water until an air bubble forms
3) Ensure the seal is airtight
4) Blot down the plant with a cloth to remove all water
5) Measure distance bubble moves in a specified amount of time
6) Repeat 5x and calculate an average

Question 22

How does the rate of transpiration change when light intensity is reduced?

Answer 22

1) Stomata close so no water can escape

2) Rate of transpiration decreases

Question 23

Which blood vessel is best suited for gas exchange?

Answer 23

Capillary-because it has a very thin wall. This provides a short diffusion distance for gases

Question 24

How can coronary heart disease cause death?

Answer 24

1) Narrowing of coronary arteries
2) Less blood is supplied to them
3) They have less oxygen
4) Reduced rate of aerobic respiration
5) Increases the risk of Agina and heart attacks
6) Which cause death

Question 25

Name 2 blood vessels that carry blood away from the heart

Answer 25

Pulmonary artery and aorta

Question 26

Define intraventricular

Answer 26

Inside ventricle

Question 27

Why does reducing oxygen kill cells?

Answer 27

1) Less oxygen means less aerobic respiration
2) So less energy
3) Cells respire anaerobically more
4) Producing lactic acid
5) This will lower the pH of the cells
6) Causing enzymes to denature

Question 28

How is the structure of a capillary adapted to help improve heart function?

Answer 28

1) One cell thick

2) Air gaps for permeability

Question 29

Lock and key hypotheses key term

Answer 29

Enzyme substrate complexes

Question 30

What blood vessel transports hormones to the liver?

Answer 30

Hepatic artery

Question 31

Hormone which causes heart rate to increase

Answer 31

Adrenaline

Question 32

Explain why dogs that have had their pancreas removed produced urine that contained glucose

Answer 32

1) No insulin was produced
2) Thus, blood glucose levels rose
3) It was therefore not converted to glycogen

Question 33

Why can rabbits that had their pancreatic duct tied can still regulate their blood glucose levels

Answer 33

The pancreas can still produce insulin

Question 34

Name the blood vessel that transports hormones to the liver

Answer 34

Hepatic artery

Question 35

One advantage of storing glycogen in cells rather than glucose

Answer 35

It is insoluble so doesn’t affect water potential

Question 36

Hormone which causes heart rate to increase

Answer 36

Adrenaline