year 12 additional questions (cell structure) ans

8/14/2019 Year 12 Additional Questions (Cell Structure) Ans

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King Edward VI Camp Hill School For Girls 1

1. (a) (i) Double layer of phospholipid molecules;

Detail of arrangement of phospholipids;

Intrinsic proteins/protein molecules passing right through;

Some with channels/pores;

Extrinsic proteins/proteins only in one layer/on surface;

Molecules can move in membrane/dynamic/membrane contains

cholesterol;Glycocalyx/carbohydrates attached to lipids/proteins; max 5

(ii) Thicker;

Single layer/presence of fibrils in cell wall; plasmodesmata; 2

(b) Non-polar/lipid soluble molecules move through phospholipid layer/bilayer;

Small molecules/water/gases move through phospholipid layer/bilayer;

Ions/water soluble substances move through channels in proteins;

Some proteins are gated;

Reference to diffusion;

Carriers identified as proteins;

Carriers associated with facilitated diffusion;

Carriers associated with active transport/transport with ATP/pumps;

Different cells have different proteins;

Correct reference to cytosis; max 6

(c) Absence of nuclear envelope/membrane;

Membrane bounded organelles;

Such as mitochondria/chloroplast/vacuole/lysosome;

and membrane systems/endoplasmic reticulum/Golgi;

Mesosomes in prokaryotes; max 4

Quality of language

Aspect of work

Grammar, punctuation and spelling of an acceptable standard 1

Material presented in an appropriate scientific style with due regard to correct use

of technical terms 1

Argument clearly and logically presented 3[20]

2. (a) (i) Ability to distinguish points (close together); 1

(ii) Electrons have a shorter wavelength; 1

(b) (i) Golgi/nucleus / mitochondrion / endoplasmic reticulum /

chromosome / larger ribosomes;

R Membrane bound structure 1

(ii) Capsule / cell wall / flagellum / mesosome /

plasmid / nucleoid / circular DNA; 1

(c) Formation/packaging of glycoproteins / glycolipids /


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secretion /modification of proteins/

formation of lysosomes / membranes / vesicles; 1[5]

3. (a) (i) Crista 1(ii) (Mitochondria) provide energy / ATP;

liver cells have high energy requirement for metabolism- reactions

specific liver function, eg. glycogen synthesis or deamination (not just:

active transport/ growth) 2

(iii) Principle - protein synthesis;

Function of protein in mitochondria - e.g. synthesis of (respiratory)

enzymes / growth / repair / replication.

or:DNA has genetic information;

ribosomes produce proteins / allows replication of mitochondria. 2

(b) Maintain concentrations/water potential same inside & outside (cells /

mitochondria) / prevent osmosis;

Prevent bursting / shrinkage of mitochondria/organelles (not cells) 2

(c) Eukaryotic ribosomes denser/ heavier (not just larger). 1[8]

4. (a) X protein synthesis / translation;Y movement; 2

(b) (i) cytoplasm;

ribosomes;

phospholipid membranes / cell membrane / semipermeable

membrane; 2 max

(accept folded membrane for two marks)


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(ii) (it = bacterium)

cell wall;

capsule;

flagellum;

mesosome;

no nucleus / nuclear membrane / DNA free;no mitochondria;

(accept no membrane-bound organelles if neither nucleus

nor mitochondria mark scored)

no microvilli;

no Golgi;

no ER;

70S/smaller ribosomes; 2 max[6]

5. (a) (i) homogeniser/blender/pestle and mortar/ description e.g. grind with sand; 1

(ii) centrifuge/ description e.g. spin at high speeds; 1

(b) (i) chloroplast; 1

(ii) (outer) membrane breaks down / inner membranes/grana separate;

solution has a higher/less negative water potential;

(accept description of relative concentrations)

water moves into organelle/chloroplast by osmosis / from higher to

lower water potential / into more concentrated solution; (reject into cell)

organelle swells/increase in pressure and bursts; 4[7]

6.

A Ribosomes Making proteins/ assembling amino acid chain/

protein synthesis

1 mark

B Mitochondria Respiration/ formation of ATP/ Krebs cycle/

Oxidative phosphorylation;

1 mark

C Nuclei DNA/RNA synthesis/ controls proteinproduction/ cell activity/ carries genetic

information;

1 mark

1 mark

[4]


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7. (a) A mitochondrion; 1

B nucleus; 1

C endoplasmic reticulum rough ER / ER;

(reject smooth ER, ribosomes neutral ) 1

(b) ref to proteins / glycoproteins / enzymes / lipids / hormones;

ref to fate of proteins / glycoproteins / enzymes / lipids / hormones; (linked to

previous mark e.g. vesicles / exocytosis / packaging / synthesis / processing

modifying)

If neither of these: reference to vesicles / exocytosis / packaging / synthesis

processing /modifying gains 1 mark

(Max 1 mark if incorrect function given) 2

(c) 30 000 - 34 000 gains 2 marks;; 2If neither of these: evidence of sensible measured diameter actual (0.0005 mm)

gains 1 mark[7]

8. (a)

Feature Epithelial cell from

small intestine

Prokaryotic cell

Golgi apparatus

Mitochondrion

Nuclear envelope

Plasmid

Ribosome

Mark down, one mark for each correct column; 2

(b) (i) Electron microscope with better resolution/ able

to distinguish between points closer together;

(Beam of electrons) with shorter wavelength; 2

(Ignore refs. to higher magnification/ more detail)

(A reverse argument for light microscope)


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(ii) Processes involved in preparation alter/distort cell contents/

introduction of artefacts; 1[5]

9. (a) Answer within limits of 6.3 - 6.7;; 2

(if outside these limits, answer involving division

of actual length by 6000 1 mark)

(b) Nitrogen), Carbon), Hydrogen) and Oxygen); 1

(c) (i) In bacterial cell, DNA / genetic material / naked /

not associated with protein / not in chromosomes/

DNA in loop / plasmid / DNA not in nucleus; 1

(ii) In bacterial cell organelles / named examples /not surrounded by membranes / bacteria only have

a plasma membrane / no endoplasmic reticulum / have mesosomes; 1[5]

10. A cell (surface) membrane,

regulates entry/exit/selectively permeable;

B mesosome,

respiration/cell division;

C cell wall,(mechanical) protection/prevents (osmotic) lysis;

D slime layer/capsule,

protection (against e.g. antibiotics);

E flagellum,

movement of cell;

F DNA molecule/bacterial chromosome,

genetic information;[6]

11. (a) (i) Mitochondria site of respiration;

Production of ATP / release of energy;

For contraction; 3

Do not award credit for making or producing energy.

(ii) Enzymes are proteins;

Proteins synthesised/made on ribosomes; 2


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(b) Lysosomes produce/contain enzymes;

Which break down/hydrolyse proteins/substances/cells of tail; 2

(c) 1. Chop up (accept any reference to crude breaking up);

2. Cold;3. Buffer solution;

4. Isotonic / same water potential;

5. Filter and centrifuge filtrate;

6. Centrifuge supernatant;

7. At higher speed;

8. Chloroplasts in (second) pellet; max 6[13]

12. (a) Nuclear pore; 1(b) Making/synthesising proteins/translation; 1

(c) Z packages/modifies/stores / transports proteins; 1

(d) Allow 2 marks for correct answer 1.3 1.4 m

Allow 1 mark for incorrect answer if measured length by 30 000 2[5]

13. (a) (i) Cooling / inhibitors; 2

stops / slows reactions;(ii) Isotonic / same / same as (as mitochondria); 2

ref to osmosis / no (net) water movement / prevent bursting

prevent shrinkage;

(b) Mitochondria and bacteria approximately same size / same density / mass /

weight; 1[5]

14. (a) (i) Short wavelength; [Allow: Small wavelength]

Good/ high resolution; [Allow: description of resolution] 2

(ii) Cut through a different plane; 1


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year 12 additional questions (cell structure) ans

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