B4 Organising animals and plants

Question 1

plasma

Answer 1

has blood cells suspended in it and transports proteins and other chemicals around the body

Question 2

red blood cells

Answer 2

contain haemoglobin that binds to oxygen to transport it from the lungs to the tissues. They have an increased surface area and no nucleus

Question 3

white blood cells

Answer 3

help to protect the body against infection

Question 4

platelets

Answer 4

cell fragments that start the clotting process at wound sites

Question 5

main types of blood vessels

Answer 5

arteries, veins and capillaries

Question 6

arteries

Answer 6

carry oxygenated away from the heart to the organs. Thick walls and thick layer of muscle and elastic fibres

Question 7

veins

Answer 7

carry deoxygenated blood to the heart. Blood is squeezed back towards the heart by the action of the skeletal muscles and valves prevent backflow. Relatively thin walls and a large lumen

Question 8

Capillaries

Answer 8

huge network of tiny vessels that link the arteries and veins. Tiny vessels with narrow lumen. Walls are just a cell thick

Question 9

Circulation system

Answer 9

humans have a double circulation system

Question 10

heart valves

Answer 10

keep the blood flowing in the right direction

Question 11

stents

Answer 11

use to keep narrowed or blocked arteries open

Question 12

statins

Answer 12

reduce cholesterol levels in the blood, reducing the risk of coronary heart disease

Question 13

how many chambers does the heart have?

Answer 13

4

Question 14

ventricles

Answer 14

bottom chambers which pump blood out of the heart

Question 15

heart process

Answer 15

blood comes from the veins into the atria, through the valves to the ventricles, and then out via arteries

Question 16

which side of the heart is thicker?

Answer 16

left

Question 17

damaged heart valves

Answer 17

can be replaced with biological or mechanical valves

Question 18

resting heart rate

Answer 18

controlled by a group of cells in the right atrium that form a natural pacemaker

Question 19

artificial pacemakers

Answer 19

electrical devices used to correct irregularities in the heart rhythm

Question 20

artificial hearts

Answer 20

used to keep patients alive while they wait for a transplant or their heart to rest as an aid to recovery

Question 21

ribcage

Answer 21

protects the lungs

Question 22

diaphragm

Answer 22

strong sheet of muscle which separates the lungs from the digestive organs below

Question 23

how are the lungs ventilated?

Answer 23

contraction and relaxation of the intercostal muscle between the ribs and the diaphragm

Question 24

adaptations of the alveoli

Answer 24

they provide a very large surface area and a rich supply of blood capillaries. This means gases can diffuse into and out of the blood as efficiently as possible

Question 25

epidermal tissue

Answer 25

covers the surface and protects the plant

Question 26

palisade mesophyll

Answer 26

contains lots of chloroplasts, which carry out photosynthesis

Question 27

spongy mesophyll

Answer 27

contains some chloroplasts for photosynthesis but also has big air spaces and a large surface area to make the diffusion of gases easier

Question 28

xylem tissue

Answer 28

carries water and mineral ions from the soil around the plant to the stem and leaves. Mature xylem cells are dead.

Question 29

phloem tissue

Answer 29

transports sugars made by photosynthesis from the leaves to the rest of the plant. Also transported to storage organs where it provides an energy store for winter. Phloem is a living tissue.

Question 30

translocation

Answer 30

the movement of dissolved sugars from the leaves to the rest of the plant

Question 31

transpiration

Answer 31

the loss of water vapour from the surface of plant leaves. Anything that affects the rate of evaporation also affects the rate of transpiration

Question 32

transpiration stream

Answer 32

As water evaporates, more water is pulled up through the xylem to take its place

Question 33

how is the water lost in plants?

Answer 33

water is lost through the stomata, which opens to let in carbon dioxide for photosynthesis. The stomata and guard cells control gas exchange and water loss

Question 34

factors affecting transpiration

Answer 34

anything that increases the rate of photosynthesis and evaporation will increase the rate of transpiration

Question 35

4 factors that affect transpiration

Answer 35

temperature, humidity, air movement and light intensity

Question 36

controlling water loss

Answer 36

most of the stomata are found on the underside of leaves

Question 37

what is used to measure transpiration rates?

Answer 37

a potometer