Transport Revision

Question 1

What does the phloem transfer and where from

Answer 1

Sugars (e.g sucrose) and amino acids from the leaves to the other parts of the plant.

Question 2

What does the Xylem transport

Answer 2

Water and minerals (nitrates, phosphates and potassium with some magnesium)

Question 3

What is Transpiration?

Answer 3

Transpiration is the loss of water from the plant through the evaporation and diffusion of water from the surface of the plant.
This causes more water to be drawn from the roots and move minerals to the leaves.

Question 4

How can a bubble potometer be used to measure transpiration rate?

Answer 4

1. Cut stem underwater
2. Assemble potometer with reservoir of water and a capillary tube with a scale
3. Watch as air bubble moves up etc

Question 5

Which environmental conditions affect the rate of transpiration

Answer 5

Light intensity, temperature, humidity and wind speed

Question 6

Why does light intensity increase the rate of transpiration?

Answer 6

The rate of photosynthesis is higher so more carbon dioxide is required. This means the stomata are open allowing for the loss of water.

Question 7

What is a mass potometer and how can it be used to measure the rate of transpiration?

Answer 7

A mass potometer is plant on an electronic balance to measure the change in mass. The change in mass is due to the loss of water through transpiration.

Question 8

What are the potential problems with a mass potometer?

Answer 8

The water in the test tube could be evaporating and causing the mass change - not transpiration. This can be fixed by using film or a layer of oil

Question 9

What is the composition and use of Platelets?

Answer 9

Platelets are small fragments of cells.
They help to clot cuts. They do this by breaking open and releasing a chemical that turns fibrinogen into fibrin. This forms threads that hold cells together and form a scab.

Question 10

What is the function of red blood cells?

Answer 10

Red blood cells transport oxygen from the lungs to the rest of the body.
They have a biconcave shape to increase their surface area.
They do not have a nucleus.

Question 11

How does a phagocyte kill a pathogen?

Answer 11

It engulfs a pathogen and then the digestive enzymes inside it digest it.
They are non-specific and attack any foreign body.

Question 12

How does a lymphocyte kill a pathogen?

Answer 12

A lymphocyte kills a pathogen by producing a pathogen called an antibody. This antibody sticks to the antigen of a bacteria and destroys it.
A lymphocyte can only kill one species of bacteria.

Question 13

How do vaccinations help to protect against diseases?

Answer 13

Vaccinations usually involve putting a dead or inactive pathogen into the body. These still carry antigens, so will still trigger an immune response.
Memory cells are produced and remain in the blood so if live pathogens of the same species return antibodies will be produced much faster.

Question 14

What features do the Arteries have?

Answer 14

The arteries have strong and elastic walls due to the high pressure that blood is pumped at.
They also have thin lumen to maintain this pressure.
Transports oxygenated blood away from the heart!

Question 15

What features does a capillary have?

Answer 15

A capillary has a wall that is only one cell thick to allow for the exchange of gases and food/waste products.
They also have very thin lumen

Question 16

What features does a vein have?

Answer 16

Veins have valves to prevent the back flow of blood. They have a bigger lumen to help blood flow despite a lower pressure.
They have a thinner wall due to the lower pressure.

Question 17

What is coronary heart disease?

Answer 17

Coronary heart disease is the the blockage of coronary arteries by the build up of fatty layers.
This restricts the blood flow and causes a lack of oxygen for the heart.
This can cause a heart attack.
Risk factors include diet (saturated fats etc), smoking and exercise (none)

Question 18

Why does humidity affect the rate of transpiration

Answer 18

A high level of humidity means that the concentration difference between the air and the plant is lower and thus diffusion will be slower

Question 19

Why does wind temperature affect the rate of transpiration?

Answer 19

This is because of the increased difference in concentration gradient.

Question 20

What is Diastole?

Answer 20

Diastole is the phase of the heartbeat where the heart muscle relaxes and the heart fills with blood.

Question 21

What is Systole?

Answer 21

Systole is the phase of the heart beat where the muscle contracts and pumps blood into the arteries.

Question 22

What is the purpose of the semi lunar valve and where is it positioned?

Answer 22

The semi lunar valves are to stop the back flow of blood into the heart and are positioned where the aorta leaves the left ventricle and where the pulmonary artery leaves the right ventricle.

Question 23

What is the position and purpose of the bicuspid valve?

Answer 23

The bicuspid valve is located between the left atrium and the left ventricle and opens due to a build up of pressure.
It closes to prevent blood back flowing through the atrium when the heart muscle contracts.

Question 24

What is the position and purpose of the tricuspid valve?

Answer 24

The tricuspid valve is positioned in between the right atrium and the right ventricle. It opens due to a build up in pressure. It prevents blood back-flowing into the aorta when the heart contracts.

Question 25

What is the difference between bicuspid and tricuspid valves?

Answer 25

Bicuspid left - oxygenated blood
Tricuspid right - deoxygenated

Question 26

Which valve is on the left?

Answer 26

Bicuspid

Question 27

Which valve is on the right

Answer 27

Tricuspid

Question 28

Why does temperature affect the rate of transpiration?

Answer 28

A high temperature increases the speed at which water evaporates and the energy of water vapour. This increases the speed of diffusion.

Question 29

What are the risk factors for coronary heart disease

Answer 29

Lack of exercise, diet with high amounts of saturated fats etc

Question 30

What is the purpose/function of plasma?

Answer 30

Plasma is the liquid where cells and cell fragments are suspended.
It transports carbon dioxide, urea, food molecules and hormones

Question 31

What is the difference between the right and left side of the heart.

Answer 31

The right side has a thinner muscle because it is only pumping to the lungs.