B4

Question 1

9 functions of the blood

Answer 1

carries oxygen from lungs to everywhere.
transports nutrients from small intestine.
defend from disease.
transport CO2 from cells to lungs.
transports waste products from cells to liver.
transports heat around the body.
transports water around the body.
transports salts around the body.
transports hormones around the body.

Question 2

main components of blood

Answer 2

plasma 55%.
red blood cells 42%.
white blood cells 0.5%.
platelets 0.5%.

Question 3

red blood cells function

Answer 3

transport oxygen. no nucleus to make more room for haemoglobin. biconcave shape for larger surface area

Question 4

white blood cells function

Answer 4

certain WBCs (phagocytes) engulf and digest bacteria and viruses. part of the body’s defence system

Question 5

platelets function

Answer 5

small fragments of cells with no nucleus. form blood clots and scabs. haemophilia is caused by being born with little or no platelets

Question 6

plasma function

Answer 6

yellow liquid, which carries the waste gas product carbon dioxide from cells to the lungs. transports urea from your liver to the kidneys

Question 7

vein

Answer 7

type of blood vessel that carries blood TO the heart, from the organs. deoxygenated. thin walls, large lumen. often has valves to prevent back flow of blood

Question 8

arteries

Answer 8

carry blood AWAY from the heart to the organs. oxygenated. thick walls, small lumen, because the blood is under high pressure.

Question 9

capillaries

Answer 9

link arteries to veins. one cell thick, narrow lumen, giving them a shorter diffusion distance

Question 10

blood flow through the heart

Answer 10

1. vena cava
2. right atrium
3. right ventricle
4. pulmonary artery
5. lungs
6. pulmonary vein
7. left atrium
8. left ventricle
9. aorta
10. body tissues

Question 11

statins

Answer 11

drugs used to lower blood cholesterol levels and improve the balance of HDLs and LDLs in the blood

Question 12

double circulatory system

Answer 12

one transport system carries blood from the heart to the lungs and back again (pulmonary). the other system carries blood from your heart to all your other organs and back again (systemic)

Question 13

inhalation

Answer 13

ribs move up and out, diaphragm flattens, volume of chest increases

Question 14

exhalation

Answer 14

ribs fall and move in, diaphragm returns to a domed shape, volume of chest decreases

Question 15

guard cell function

Answer 15

control the opening and closing of the stomata

Question 16

stomata function

Answer 16

allow gases to move in and out of the leaf

Question 17

xylem function

Answer 17

carries water and dissolved minerals from the roots to the leaves - transpiration

Question 18

phloem function

Answer 18

carries dissolved sugars from the leaves around the plant - translocation

Question 19

transpiration

Answer 19

the loss of water vapour from the leaves of plants through the stomata, when they are opened, to allow gas exchange for photosynthesis

Question 20

describe how to collect data from the number of stomata on a leaf

Answer 20

mount epidermis on slide
count stomata in one area
repeat in four more areas
repeat method on other side of leaf
calculate mean

Question 21

why is it an advantage to have few stomata on the upper surface of a leaf?

Answer 21

less water loss, to the plant does not wilt