Mark scheme Questions (4 marks)

Question 1

describe how damage to the alveoli in the lungs leads to emphysema

Answer 1

emphysema damages the alveoli
by thinking or scarring it

makes air sacks larger
decreases surface area
therefore less diffusion of gas

Question 2

describe how the build up of cholesterol in the artery increase the risk factor in the development of athroscolsis

Answer 2

cholesterol builds up with fatty substances to form plaque

plaque builds up slowly

cells in the artery’s preforms and internal response

the arteries become stiff and narrow

Question 3

explain how L-dopa affects synaptic transmission in a person with Parkinson’s diseases

Answer 3

L-dopa starts off the production of dopamine

L-dopa increase the amount of the dopamine realised for a pre synaptic cleft

normal levels of dopamine received at the post synaptic neurone

Question 4

explain how the mid-piece of a human sperm cell is specialised to support the function of its tail

Answer 4

the tail gives mobility

which uses large amounts of atp/energy

provided by large numbers of mitochondria contained in the mid piece

Question 5

Explain the function of the sarcoplasmic recitclium in the skeletal muscle tissue

Answer 5

controls the uptake and release of calcium ions

which controls ATPase activity

and therefore the contraction of the muscle

Question 6

name of technique to find out if bacteria is gram positive or gem negative

Answer 6

technique: gram staining
result gram p: turns purple
result gram n: turns red

Question 7

magnification equation

Answer 7

image size = object size x magnification

micro    
milli      x10
centi    x 1000
nano   x 1000

Question 8

suggest an explication why young hearts are the best ones to use in transplants

Answer 8

young hearts have less athrosolsis

better supply of blood/glucose/ oxygen to heart muscle cells

therefore a young heart will last longer

Question 9

explain the difference in the speed of the nerve impulse along theses axons

Answer 9

mylenated axons have schwann cells/nodes of ranvier

therefore the impulse/ action potential jumped from one node to the next

therefore depolarisation only at nodes (grater speed of nerve impulse )

Question 10

explain how pesticides kill small animals

Answer 10

acetylchoiline builds up in cleft

therefore constant depolarisation of post post synaptic membrane

and content action potential/ impulses to muscles

so muscles permanently contracted

Question 11

explain the function of the sarcoplasmic reticulum in the skeletal muscle tissue

Answer 11

controls the uptake and releases of calcium ions

which controls ATpase activity

and therefore the contraction of the muscle

Question 12

describe the changes in membrane permeability at point 1 on the graph

Answer 12

na channels open at -70mv

axon cell becomes more permeable to na

concentration gradient of na ions exist across the membrane

diffusion of na ions go into the nerve

Question 13

explain how hyperpolorisation in an axon cell

Answer 13

k ions open

close more slowly than na channels

excess k ions diffuse out of the neurone

potential difference becomes more negative than resting potential -70mV