Ch4 Organising animals and plants

Question 1

carpillaries

Answer 1

form a huge network of tiny vessels linking arteries and veins
tiny vessel with narrow lumen

Question 2

properties of carpillaries

Answer 2

thin, permeable single-cell wall to allow efficient diffusion of substances

Question 3

arteries

Answer 3

carries blood away from heart to organs
blood is oxygenated
they stretch as blood is forced through them by heartbeat

Question 4

properties of arteries

Answer 4

thick walls full of muscles and elastic fibres

small lumen

Question 5

veins

Answer 5

carry blood to heart away from organs
blood is deoxygenated
blood is squeezed by action of skeletal muscles

Question 6

properties of veins

Answer 6

thinner walls
have valves to prevent backflow of blood
large lumen

Question 7

coronary heart disease

Answer 7

coronary arteries that supply blood to heart becomes narrow
caused by build-up of fatty material of lining of vessels
causes lack of oxygen

Question 8

stent

Answer 8

balloon inflates metal mesh in blood vessel, which opens it up freeing blood flow

Question 9

benefeits of stents

Answer 9

can also release drugs to prevent blood clotting
doesn’t need general anaesthetic
can be used anywhere in the body

Question 10

statins

Answer 10

reduce blood cholesterol levels

slows down formation of fatty deposits in coronary arteries

Question 11

replacing coronary arteries

Answer 11

bypass surgery
replaced with bits of veins from other part of the body
expensive

Question 12

mechanical replacement heart valves

Answer 12

made of titanium and polymers
last a long time
have to take medication for rest of your life to prevent blood clots
can be rejected, cause bleeding or infection

Question 13

biological replacement heart valves

Answer 13

taken from animals(e.g. pigs or cattle)
doesn’t need medication
only last 12-15 years

Question 14

artificial pacemakers

Answer 14

sends electric signals to heart to stimulate beat properly
needs surgery(can cause bleeding and infection)
needs regular medical check-ups

Question 15

natural pacemaker

Answer 15

group of cells in right atrium

controls rhythm of the heart

Question 16

artificial heart

Answer 16

temporary when waiting for donor heart
needs lot of machinery to work
risk of blood clot
expensive
can be rejected

Question 17

alveoli adaptations

Answer 17

large SA(more area for diffusion)
rich supply of blood carpillaries(maintains steep conc gradient)
single-cell wide walls(shortest possible distance for diffusion)
large ventilation

Question 18

transpiration

Answer 18

the evaporation of water from plants occurring at the leaves

Question 19

4 factors that increase transpiration rate

Answer 19

1. warm temp(molecules move faster so diffusion is more rapid)
2. high light intensity(more stomata open)
3. low humidity(diffuses faster into dry air because steep conc gradient)
4. good air flow

Question 20

translocation

Answer 20

The movement of dissolved sugars from the leaves to the rest of the plant (occurs in the phloem)

Question 21

Heart

Answer 21

Pumps blood around the body in a double

circulatory system

Question 22

vena cava

Answer 22

brings deoxygenated blood into the right atrium from the body

Question 23

pulmonary vein

Answer 23

brings oxygenated blood into the left atrium from the lungs

Question 24

right ventricle

Answer 24

forces deoxygenated blood into the lungs from the pulmonary artery

Question 25

left ventricle

Answer 25

forces oxygenated blood around the body in the aorta
thicker wall
- develops pressure needed to force blood

Question 26

valves

Answer 26

prevent backflow of blood

create a pulse