Unit 2 + 3

Question 1

what is the role of the golgi apparatus

Answer 1

involved in the process and packaging of proteins

Question 2

role of lysosomes

Answer 2

its a digestive enzyme which digests worn out parts of the cell

Question 3

what are the roles of a slime capsule

Answer 3

• stops the cell from drying out
• protects it from enzymes

Question 4

why are viruses acellular

Answer 4

because they do not have a cellular structure

Question 5

what is cell fractionation

Answer 5

when cells are broken up and their organelles are seperated because they have different densities

Question 6

why is the solution for cell fractionation placed in cold water

Answer 6

it reduces enzyme activity

Question 7

why is the solution for cell fractionation placed in an isotonic solution

Answer 7

it prevents the cell from shrinking or bursting

Question 8

why is the solution for cell fractionation placed in a buffered solution

Answer 8

so the pH stays the same

Question 9

what are some limitations to using a TEM

Answer 9

• may contain artefacts
• image is 2D

Question 10

what is binary fission

Answer 10

how bacteria reproduce as it is an asexual process

Question 11

what makes up the bilayer

Answer 11

phospholipids and protein

Question 12

define active transport

Answer 12

the movement of particles from low to high concentration across a semi-permeable membrane

Question 13

define osmosis

Answer 13

the movement of water from a high to low concentration against a semi permeable membrane

Question 14

give 3 ways you can increase the rate of diffusion

Answer 14

• increase concentration gradient
• increase surface area
• change diffusion path

Question 15

what are spiracles

Answer 15

microscopic holes in the body of insects which can open + close

Question 16

what causes spiracles to open

Answer 16

a rise in CO2

Question 17

link haemoglobin with affinity

Answer 17

when its in the heart its affinity is high so it carries a lot of oxygen
when it leaves the heart its affinity lowers so it unloads it quicker

Question 18

what are the 3 compartments of a fish gill

Answer 18

• flap
• bar
• filaments

Question 19

how are gills beneficial to fish

Answer 19

they contain many lamellae which increases its surface area

Question 20

what is meant by a counter current

Answer 20

when blood flows one way and water flows the other

Question 21

how are gills efficient at diffusion

Answer 21

they ensure the oxygen in water is always just higher than the water so diffusion can occur

Question 22

what circulatory system do humans have
what system does a fish have

Answer 22

humans - double
fish - single

Question 23

what are the 2 phases of the cardiac cycle

Answer 23

diastole and systole

Question 24

what is the diastole phase

Answer 24

it refers to the ventricular filling

Question 25

what is the systole phase

Answer 25

the ventricular contraction

Question 26

when do the AV valves open

Answer 26

when the pressure in the atrium is greater than the pressure in the ventricle

Question 27

give the features of an artery

Answer 27

• high pressure
• elastic tissue
• smooth inner endothelial lining

Question 28

how does the elastic tissue benefit the artery

Answer 28

it allows it to stretch and recoil

Question 29

how does the smooth inner endothelial lining benefit the artery

Answer 29

it removes friction so more blood flow

Question 30

give the features of a vein

Answer 30

• thin collagen layer as pressure is low
• valves which prevent backflow

Question 31

give the features of capillaries

Answer 31

• single cell walls of endothelial for easy diffusion
• narrow lumen which reduces flow rate giving more time for diffusion

Question 32

what is meant by tissue fluid

Answer 32

when the liquid plasma leaks out of the capillaries

Question 33

what links companion cells

Answer 33

plasmodesmata

Question 34

what is a stylet

Answer 34

what aphids use to penertrate phloem tubes and sip sugary sap

Question 35

describe the cohesion - tension theory of water transport

Answer 35

• the stomata in the leaves open as transpiration increases
• as transpiration occurs the water potential decreases
• water is pulled up the xylem which creates tension
• water molecules stick together via cohesion

Question 36

how is the highest pressure produced in the left ventricle

Answer 36

stronger contractions / thicker muscle

Question 37

which vessel has the thickest muscles

Answer 37

the left ventricle

Question 38

what would happen if babies are born with a hole between their right and left ventricle

Answer 38

the oxygenated and deoxygenated blood would mix together so the volume of oxygenated blood would be lower

Question 39

whats an advantage to using a pH meter over a colourimeter

Answer 39

greater accuracy as it gives a numerical reading

Question 40

what type of bond is broken when chain of amino acids is hydrolysed

Answer 40

peptide

Question 41

how does an inhibitor stop an enzyme working

Answer 41

• inhibitor is similar shape to substrate
• so it binds to the active site
• this stops the enzyme binding to actual substrate

Question 42

explain the role of the diaphragm in breathing out

Answer 42

• diahphragm moves up
• this reduces the volume in the thorax / increases pressure
• so the pressure in the thorax is higher than outside