Topic 3 - Mass Transport in Animals

Question 1

Describe the arteries

Answer 1

Carry blood away from the heart
Thick muscular walls
Small lumen
Oxygenated blood
High pressure
No valves

Question 2

Describe the veins

Answer 2

Carry blood towards the heart
Thin elastic wall
Large lumen
Deoxygenated blood
Low pressure
Valves to prevent backflow

Question 3

Describe the capillaries

Answer 3

Carry blood between cells in tissues
One cell thick wall
Narrow
Medium pressure

Question 4

Describe the structure of haemoglobin

Answer 4

Quaternary protein
2 alpha and 2 beta chains
Each polypeptide is joined to a haem group

Question 5

How many haem groups does a molecule of haemoglobin contain?

Answer 5

4

Question 6

What is partial pressure?

Answer 6

Pressure exerted by each part of a mixture such as air.

Question 7

Explain the Bohr shift

Answer 7

Where there is more CO2, more H+ ions in red blood cells, oxyhemoglobin releases more oxygen

Question 8

What does it mean if the oxygen dissociation curve for haemoglobin shifts right.

Answer 8

There is more CO2, giving up more oxygen for respiring cells.

Question 9

What is CO2 converted to in red blood cells?

Answer 9

Hydrogen carbonate Ions (HCO3)

Question 10

Explain the oxygen dissociation curve of haemoglobin for an organism living in anaerobic conditions

Answer 10

Shifted to the left compared to human haemoglobin

Question 11

What is the function of the superior vena cava?

Answer 11

Brings deoxygenated blood from the body and empties into the right atrium

Question 12

What is the function of the right atrium?

Answer 12

Receives deoxygenated blood from the super vena cava

Question 13

What is the function of the inferior vena cava?

Answer 13

Brings deoxygenated blood from lower body into the right atrium

Question 14

What is the function of the pulmonary artery?

Answer 14

Transports deoxygenated blood from the right ventricle to the lungs.

Question 15

What is the function of the pulmonary vein?

Answer 15

Brings oxygenated blood from pulmonary vein, contraction of SA node progresses through atria the blood passes through the valve into the left ventricle.

Question 16

What happens when the left ventricle is filled with blood?

Answer 16

It contracts, valve closes and aortic value opens to allow blood into the aorta.

Question 17

Which part of the heart carries oxygen rich blood from the left ventricle to the body?

Answer 17

Aorta

Question 18

What are coronary arteries?

Answer 18

Arteries that branch from the aorta to supply oxygenated blood to the heart muscles.

Question 19

What are the capillaries of the coronary artery responsible for?

Answer 19

Transporting red blood cells taking them away from the heart.

Question 20

Explain what root hair cells in plants are responsible for

Answer 20

Uptake of water and vital minerals.

Question 21

What is the structure of root hair cells ?

Answer 21

Very large surface are and very short diffusion distance.

Question 22

Where are root hair cells located?

Answer 22

Close to the top of the root and extend into soil.

Question 23

Movement of water up the stem of a plant is caused by which two methods?

Answer 23

Root pressure
Transpiration pull

Question 24

Explain transpiration pull

Answer 24

Cohesion due to hydrogen bonding between water molecules to pull the water up the xylem. As water evaporates from leaves, more water is pulled up the xylem from the root to the leaves to replace it.

Question 25

Explain the cohesion tension theory

Answer 25

Xylem is a tube, once water enters it there are no barriers to stop water movement from the root to the top. As water is continuously lost by transpiration, water is always flowing up the plant

Question 26

What happens to the circumference of the plant stem during rapid transpiration?

Answer 26

Shrinks rather than grows

Question 27

Define transpiration

Answer 27

The loss of water from the leaves of plants by diffusion

Question 28

How does light intensity affect the rate of transpiration?

Answer 28

The greater the light intensity means there is more evaporation and more transpiration (during hours of darkness is closed)

Question 29

How does temperature affect the rate of transpiration?

Answer 29

Increase temperature increases the rate of transpiration as water molecules have more energy

Question 30

How does air movement affect the rate of transpiration?

Answer 30

More wind resulting in an increased rate of transpiration as the leaf will not become saturated with molecules instead the water molecule will blow away

Question 31

How does humidity affect the rate of transpiration?

Answer 31

More humidity would decrease the rate of transpiration as there is a lower concentration gradient as there is more water already in the air

Question 32

What is the mass flow hypothesis?

Answer 32

Takes place as mass movement through the phloem tissue along the gradient from a high solute concentration to a low solute concentration

Question 33

Describe translocation

Answer 33

The mass flow of solid from the source where the solids are produced to the parts where the photosynthate is needed