B5. Transportation

Question 1

function of xylem/ phloem

Answer 1

xylem: transpiration
water, minerals ions
root → leaves

phoelm: translocation
food substances
leaves → rest of plant

Question 2

define transpiration

Answer 2

evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata

Question 3

function of root hair cell

Answer 3

plant absorbs water and minerals ions by osmosis

• large SA and extension
• semi permeable membrane

Question 4

State the pathway taken by water

Answer 4

1. water enters a root hair cell by osmosis
2. passes across the cells of root cortex down a water potential gradient
3. passes xylem and up the stem to the leaves

Question 5

Investigate, using a suitable stain, the pathway of water

Answer 5

*diagram
apparatus set up for potometer 
- cut shoot
-reservoir
-capillary tube 
-water beaker
-ruler
As water moves up through the plant the air bubble moves along the scale giving a measure of water absorbed by the plant over time

Question 6

Define translocation

Answer 6

movement of sucrose and amino acids in phloem
from regions of production to regions of storage/
utilisation in respiration or growth.

Question 7

water uptake in term of transpiration

Answer 7

transpiration produces tension (‘pull’) from above,
creates a water potential gradient in xylem,
draws cohesive water molecules up the plant.

Question 8

effects on transpiration rate

Answer 8

• light: stomata open for gas exchange
• temp: faster evaporation of water from mesophyll surface
• wind: high concentration gradient for diffusion
• humidity: decrease difference in water molecules concentration (inside/outside)

Question 9

state the function of blood

Answer 9

red blood cells - no nuclei/ has haemoglobin to binds with oxygen

white blood cells - defend body against infection and kill bacteria: phagocytosis and antibody formation

platelets - causes blood clotting

plasma – transport of blood cells, ions, soluble nutrients, hormones and carbon dioxide.

Question 10

describe double circulation

Answer 10

low-pressure circulation to the lungs
a high-pressure circulation to the body tissues

• Oxygenated blood is kept separate from deoxygenated blood by septum
• blood pressure circulation: systemic > pulmonary.
  The right ventricle,thinner wall and pumps blood to lungs lower pressure,avoid lung damage.

Question 11

see position of xylem and phoelm pic

Answer 11

see position of xylem and phoelm pic

Question 12

describe phagocytosis and

Answer 12

phagocyte - engulf bacteria
→moves toward bacteria,flow around
→enclose bacteria in vacuole
→enzymes are secreted, digest bacteria
→soluble substances diffuses from vacuole to cytoplasm

Question 13

describe antibody formation

Answer 13

-make antibodies that recognise pathogens’s antigens
A different antibody is produced for each antigen.
- make them stick together
- neutralise toxin
-dissolves cell membrane.

memorise antigens body has been exposed to.
→ can rapidly produce antibodies to respond

Question 14

describe tissue rejection

Answer 14

Transplants: replaces damaged organ with donor organ
→ triggers an immune response
→ antibodies are secreted
→immune system regconise cell as ‘foreign’/
→ attack and destroy/ organ rejection

Question 15

9 Describe the structure and functions of
arteries
veins
capillaries

Answer 15

ARTERIES

• carry blood away from heart
• carry oxygenated blood.
• high pressure
• thick muscular walls/elastic fibre/small lumen

VEINS

• carry blood to heart
• carry deoxygenated blood
• low pressure
• valves to prevent backflow

CAPPILIARIES

• found in muscles/lungs
• microscopic: one cell thich
• very low blood pressure
• site of gas exchange(food substance,O2)
• semi permeable wall

Question 16

8 Name the main blood vessels to and from

the heart, lungs, liver and kidney

Answer 16

pulmonay artery lung pulmonary vein
vena cava heart aorta
hepatic vein liver hepatic artery
hepatic portal vein stomach mescentric artery
renal vein kidney renal artery

Question 17

6 Investigate the effect of physical activity on pulse rate.

Answer 17

exercise
→ need more energy.
→ respire more
→ required more O2/produces more CO2
→ breathing rate increases to supply oxygen
→ heart beats faster to pump more oxygenated blood to the muscles

Question 18

Describe coronary heart and state the possible causes

Answer 18

build of cholesterol that acts as coronary arteries blocage
state
→ heart muscles dosent get enough O2/nutrients
→ no respiration → die

CAUSES
lack of excercise
high fat diet
diabetes
high blood pressure
genetic
stress
smoking

Question 19

what produces heart sound

Answer 19

closing of the atrioventricular/ semicular valves