Year 10 Revision Booklet Mark Scheme

Year 10 Revision Booklet Mark Scheme

M1.

(a) (cell) wall
(cell) membrane
cytoplasm
vacuole

for 1 mark each

4

(b) (i) A

(ii) B

for 1 mark each

2

(c) diffusion (reject osmosis)

for 1 mark

1

[7]

M2.

(a)A − saliva(ry) gland

1

B − liver

1

C − duodenum

ignore small intestine

1

D − pancreas

accept phonetic spellings

1

(b) (i)any three from:

•chewing / muscle contraction / mechanical digestion

allow churning

•protease enzymes

allow pepsin / trypsin

•in stomach / small intestine / duodenum / from pancreas

•(break down protein) into amino acids

allow (poly)peptides

3

(ii)neutralises acid pH / makes conditions alkaline

1

so lipase can work

1

emulsifies fat

1

to give large(r) surface area for lipase / enzyme action

1

(c) (i)starch

ignore carbohydrate

1

(ii)breakdown stops

allow slows down

1

because stomach produces / contains acid / has low pH

1

and amylase cannot work in acid / low pH

accept amylase is denatured / changes shape

1

[15]

M3. red (blood cell)

1

platelet

1

white (blood cell)

1

plasma

1

[4]

M4.

(a) A – artery
B – capillary
C – vein

3

(b) transport OWTTE

1

(c) increased oxygen decreased carbon dioxide

2

[6]

M5.(a)

3

(b) (trachea) has mucus

1

to trap pathogens

1

(trachea) has cilia

1

to move mucus out of trachea

1

(c) dependent variable:

number of times mosquitoes landed on socks

1

control variable, any one from:

•number of mosquitoes in each container

•length of time socks worn

•dampness of socks

•same type of socks

•size of container

•time

•temperature

•species of mosquito

•age of mosquito

1

(d) use worn socks

or

use chemical from worn socks

1

to attract / trap infected mosquitoes

1

or accept:

wear clean socks / change socks regularly (1)

to reduce the chance of attracting mosquitoes (1)

(e) less chlorophyll present

1

(so) less light absorbed

1

(so) reduced photosynthesis

or

(so) less sugar / food made

1

[14]

M6.

(a) (bacteria) produce toxins / poisons

1

(viruses) damage / kills cells or toxins released from cell

1

(b) any two from:

• viruses live inside cells

• viruses inaccessible to drug

• drug would damage body cells / tissue

2

(c) any four from:

• overuse of antibiotics

• bacteria mutate

do not allow antibiotic causes mutation

• antibiotics kill non-resistant strains or idea of selection

• reduced competition

• resistant bacteria reproduce

4

[8]

M7.

(a) use antibiotics; or named one to kill bacteria; (not microbes)

each for 1 mark

2

(b) some ingest/digest bacteria (not microbes) OWTTE
some produce antibodies;
which destroy bacteria/viruses;
some produce antitoxins;
which counteract poisons released by bacteria

each for 1 mark

5

[7]

M8.

(a) (i)protons

allow “protons or electrons”, but do not allow “protons and electrons”

1

(ii)protons plus / and neutrons

1

(b) (because the relative electrical charges are) −(1) for an electron and +(1) for a proton

allow electrons are negative and protons are positive

1

and the number of electrons is equal to the number of protons

if no other mark awarded, allow 1 mark for the charges cancel out

1

(c) (the electronic structure of) fluorine is 2,7 and chlorine is 2,8,7

allow diagrams for the first marking point

1

(so fluorine and chlorine are in the same group) because they have the same number of or 7 electrons in their highest energy level or outer shell

if no other mark awarded, allow 1 mark for have the same / similar properties

1

(d) S

1

(e) (i)ions

1

(ii)molecules

1

[9]

M9.

(a) Li and K

either order

allow lithium and potassium

1

(b) Fe

allow iron

1

(c) N and As

either order

allow nitrogen and arsenic

1

(d) Cu

allow copper

1

[4]

M10.

(a) same number of electrons in outer shell/highest energy level
or they all form 1+ ions
If number of electrons is given it must be correct
Allow loss of same number of electrons to give full shell
not gain of electrons

for 1 mark

1

(b) electrons are lost more readily/more easily
further from nucleus/bigger atom/more shielding/more energy levels/
not just more electrons
not just reduced attraction

for 1 mark each

2

[3]

M11

.(a) magnesium loses electrons

there are four ideas here that need to be linked in two pairs.

1

two electrons

1

chlorine gains electrons

magnesium loses electrons and chlorine gains electrons scores 2 marks.

1

two atoms of chlorine

magnesium losestwo electrons and two chlorines each gain one electron will score full marks.

1

(b) 95

correct answer with or without working gains 2 marks

if answer incorrect, allow 24 + 35.5 + 35.5 for 1 mark

2

[6]

M12.

(i) 1

(ii) weak forces

accept weak bonds

1

between molecules / intermolecular

reject intramolecular

1

[3]

M13.

(a) carbon

allow C

1

(b) (i)(atoms are in) layers (that) can slide over each other

1

because between the layers there are only weak forces

accept because there are no (covalent) bonds between the layers

accept Van der Waals forces between the layers

do not allow intermolecular bonds between the layers

if no other marks are awarded allow weak intermolecular forces for 1 mark

1

(ii)because each atom forms four (covalent) bonds or (diamond is a) giant (covalent) structure or lattice or macromolecular

any reference to ionic / metallic bonding or intermolecular forces scores a maximum of 1 mark

accept carbon forms a tetrahedral shape

1

(and) covalent bonds are strong

accept covalent bonds need a lot of energy / difficult to break

1

(iii)because graphite has delocalised electrons

allow sea of electrons
allow each carbon atom has one free electron

1

which can move through the whole structure (and carry the current / charge / electricity)

1

[7]

M14.

(a) (i)40

correct answer with or without working or incorrect working

if the answer is incorrect then evidence of 24 + 16 gains 1 mark

ignore units

2

(ii)60

correct answer with or without working or incorrect working

if the answer is incorrect then evidence of 24/40 or 24/(i) gains 1 mark

ecf allowed from part(i)

ie 24/(i) ×100

ignore units

2

(iii)15

ecf allowed from parts(i) and (ii)

24/(i) × 25 or (ii)/100 × 25

ignore units

1

(b)(i) any two from:

ignore gas is lost

•error in weighing magnesium / magnesium oxide

allow some magnesium oxide left in crucible

•loss of magnesium oxide / magnesium

allow they lifted the lid too much

allow loss of reactants / products

•not all of the magnesium has reacted

allow not heated enough

allow not enough oxygen / air

2

(ii)any two from:

ignore fair test

•check that the result is not anomalous

•to calculate a mean / average

allow improve the accuracy of the mean / average

•improve the reliability

allow make it reliable

•reduce the effect of errors

2

[9]

M15.

(a) (i)aluminium oxideignore (III) after aluminium

1

(ii)(because it provides) heat / energy (to overcome activation energy)

1

(b) (i)contains only one sort of atom

1

(ii)the atoms (in cast iron) are different sizes

any mention of molecules, maximum 1 mark

accept layers are distorted or structure is disrupted

1

which prevents the layers / rows sliding

accept an answer in terms of pure iron being softer than cast iron for both marks

1

(c) (i)because aluminium is more reactive than carbon

‘it’ = aluminium must be a comparison between the elements

or

because aluminium is above carbon in the reactivity series

do not accept any comparison of the reactivity of aluminium and iron

1

(ii)reduces / lowers the temperature for the process or lowers the operating temperature or allows ions to move

ignore any temperature values

allow reduces the (effective) melting point (of Al2O3 )

1

(iii)3

accept multiples

1

(iv)electrons are gained (by Al3+)

ignore any numbers

ignore any reference to oxygen

1

(v)electrodes are made of carbon

allow graphite / coke

1

oxygen is produced (at the positive electrode / anode)

accept 2O2− → O2 + 4e−

1

so the electrodes react with the oxygen / are oxidised

1

producing carbon dioxide (gas)

accept C + O2 → CO2 for marking points 3 and 4.

1

[13]

M16. sodium nitrate

1

NaNO3

do not credit lower case N or O, upper case A

1

potassium sulphate

1

K2SO4

accept potassium hydrogen sulphate or KHSO4
do not credit lower case K, S or O
ignore charges on ions

1

[4]

M17.(a) (i)electrical

correct order only

1

kinetic

1

sound

1

(ii)transferred into surroundings / atmosphere

accept warms the surroundings

allow released into the environment

becomes heat or sound is insufficient

1

(b) 0.7 / 70 %

an answer of 70 without % or with the wrong unit or 0.7 with a unit gains 1 mark

2

[6]

M18.

(a) 0.093 A

1

(b) 0.093 A

1

(c) (increasing the resistance) decreases the current

1

therefore (the lamp will be) dimmer

1

(d) potential difference = current × resistance

accept correct rearrangement with R as subject

1

(e) 3.3 = 0.15 × R

1

R = 3.3 / 0.15 (Ω)

1

R = 22 (Ω)

1

allow 22 (Ω) without working shown for 3 marks

(f) line drawn from the origin with a decreasing gradient.

1

[9]

M19.

(a) electrons

1

(b)

extra lines from a symbol negate the mark 3

(c) the total power = 7360 watts

1

current = 7360 ÷ 230

1

= 32 A

allow 32 with no working shown for 3 marks

1

so the current is greater than 30 A

1

(d) to increase the voltage (across the cables) or to decrease the current (through the cables)

1

reducing energy losses (in the cables)

do not allow electricity for energy

do not allow no energy loss

1

increasing the efficiency of transmission

1

(e) to decrease the potential difference for domestic use

1

(f)

1

(g) 405 / 900

1

=0.45

accept 45%

1

allow 0.45 or 45% with no working shown for 2 marks

[15]

M20.

(a) (i)K and L

both answers required either order

1

(ii)(1) same number of protons

accept same number of electrons

accept same atomic number

1

(2) different numbers of neutrons

1

(b)(i)90

1

(ii)140

1

(c) alpha (particle)

reason may score even if beta or gamma is chosen

1

mass number goes down by 4or
number of protons and neutrons goes down by 4
or
number of neutrons goes down by 2

candidates that answer correctly in terms of why gamma and beta decay are not possible gain full credit

1

atomic / proton number goes down by 2or
number of protons goes down by 2

accept an alpha particle consists of 2 neutrons and 2 protons for 1 mark

accept alpha equals 42He or 42α for 1 mark

an alpha particle is a helium nucleus is insufficient for this mark

1

[8]

M21. 2 weeks

if answer is incorrect 2 gains two marks weeks gains one mark
half of 68 or 34 gains one mark / allow working shown on graph

[3]