Exchange and Transport

Question 1

volume and surface area relationship

Answer 1

the larger the organism is, the smaller it’s surface area is compared to its volume

Question 2

Why can substances directly diffuse across a membrane?

Answer 2

because they have a large surface area compared to their volume

Question 3

why is it good to have a large surface area compared to volume?

Answer 3

it means enough substances can be exchanged across the membrane to supply the volume of the cell

Question 4

what is the lungs job?

Answer 4

to transfer oxygen to the blood and remove waste carbon dioxide

Question 5

how do substances diffuse faster?

Answer 5

if there is a bigger difference in concentration

Question 6

what does the blood arriving at the alveoli contain?

Answer 6

lots of CO2 and not much O2

Question 7

why does it not have a lot of O2?

Answer 7

because it has just returned to the lungs from the rest of the body

Question 8

how is the alveoli adapted?

Answer 8

moist lining to dissolve gases
good blood supply to maintain concentration gradient
very thin walls to minimise distance gases have to move
enormous surface area

Question 9

what is the other name for red blood cells?

Answer 9

erythrocytes

Question 10

what is the job of red blood cells?

Answer 10

carry oxygen from the lungs to all the cells in the body

Question 11

what shape are red blood cells?

Answer 11

biconcave disc

Question 12

what is good about a biconcave disc shape?

Answer 12

gives a large surface area to absorb oxygen

Question 13

why don’t red blood cells have a nucleus?

Answer 13

allows more room to carry oxygen

Question 14

what is haemoglobin?

Answer 14

red pigments in red blood cells which contain iron

Question 15

how does oxyhaemoglobin get made?

Answer 15

when haemoglobin binds with oxygen

Question 16

what is phagocytosis?

Answer 16

when white blood cells change shape to engulf unwelcome micro organism

Question 17

what is another name for a white blood cell?

Answer 17

phagocytes

Question 18

do white blood cells have a nucleus?

Answer 18

yes

Question 19

what do platelets do?

Answer 19

help blood clot at a wound to stop blood pouring out and stop micro organisms getting in

Question 20

what are platelets?

Answer 20

small fragments of cells with no nucleus

Question 21

what is plasma?

Answer 21

liquid that carries everything in blood

Question 22

what do arteries do?

Answer 22

carry blood away from the heart

Question 23

what do capillaries do?

Answer 23

exchange materials at tissues

Question 24

what do veins do?

Answer 24

carry blood to the heart

Question 25

why do arteries have strong walls?

Answer 25

because they carry high pressure blood

Question 26

features of an artery

Answer 26

thick lumen thick layers of muscle elastic fibres to allow them to stretch and spring back

Question 27

why are capillaries narrow?

Answer 27

so they can squeeze between gaps and get really close to cells to exchange substances

Question 28

why do capillaries have permeable walls?

Answer 28

so substances can diffuse in and out

Question 29

why are capillaries walls one cell thick?

Answer 29

it increases the rate of diffusion by decreasing the distance which it occurs

Question 30

why do veins have thin walls?

Answer 30

because they carry low pressure blood

Question 31

why do veins have bigger lumen?

Answer 31

to help the blood flow despite it being low pressure

Question 32

why do veins have valves?

Answer 32

to stop backflow of blood

Question 33

what kind of circulatory system does animals have?

Answer 33

double

Question 34

what type of blood do veins carry?

Answer 34

de oxygenated blood

Question 35

how does the circulatory system work?

Answer 35

- the heart pumps deoxygenated blood to the lungs - oxygenated blood returns to heart - oxygenated blood goes to other organs - deoxygenated blood returns to heart

Question 36

Right Atrium

Answer 36

receives deoxygenated blood from body

Question 37

right ventricle

Answer 37

pumps deoxygenated blood to the lungs

Question 38

left atrium

Answer 38

receives oxygenated blood from lungs

Question 39

left ventricle

Answer 39

pumps oxygenated blood sound the whole body

Question 40

why does the left ventricle have a thicker wall than the right?

Answer 40

because it needs more muscle to pump high pressure blood around the whole body

Question 41

how to calculate how much blood is pumped around the whole body?

Answer 41

heart rate * stroke volume

Question 42

what is respiration?

Answer 42

the process of transferring energy from the breakdown of organic compounds

Question 43

what type of reaction is respiration and why?

Answer 43

exothermic because energy is transferred to the environment

Question 44

aerobic respiration equation

Answer 44

glucose + oxygen = carbon dioxide + water

Question 45

what happens in anaerobic respiration?

Answer 45

glucose is only partially broken down and lactic acid is produced

Question 46

equation for anaerobic respiration in animals

Answer 46

glucose = lactic acid

Question 47

equation for anaerobic respiration in plants

Answer 47

glucose = ethanol + carbon dioxide

Question 48

what is the energy used for in respiration?

Answer 48

metabolic processes contracting muscles maintaining steady body temp