Warm-up

image, cell, eyepiece, focus, slide, light[1 mark per correct label, to a maximum of 6]

M / Q / Y / E / A / R / E / D / I / L / S / A
M / R / D / Y / F / I / C / A / T / L / O / N
I / U / C / E / P / K / D / R / O / X / G / C
M / H / T / P / F / O / C / U / S / E / R / E
A / H / D / I / U / E / A / L / T / U / O / S
G / E / N / E / T / S / C / T / I / N / Y / T
E / V / A / C / E / I / C / I / L / G / T / O
T / N / G / E / T / S / O / O / J / K / H / R
U / P / C / E / L / L / E / N / D / A / N / T

Main test

Qu No / Answer / Marks / Level and guidance
1 / cells
microscope / 2 /
2 / / 3 /
3 / A: nucleus
B: cell wall
C: vacuole / 3 /
4 / pull
push / 2 /
5 / Cytoplasm / Nucleus / Cell wall / Chloroplasts
Musclecell /  / 
Bacterial cell /  / 
/ 4 /
6 / Any one from the following:
  • The cell wall supports the cell/plant.
  • It helps the cell/plant keeps its shape.
  • It keepsthe cell rigid.
(do not accept cell wall protects cell(s)) / 1 /
7 / The surface area of a membrane controls how many molecules can enter at once.
Diffusion happens quicker in small cells because there is a larger surface area to volume ratio. / 2 /
8 / (i) The biceps contracts and the triceps relaxes.
(ii) Ligaments can stretch to allow movement or bending (otherwise they could snap or break). / 2 /
9 / (i) The cilia push the egg along from the ovary to the uterus.
(ii) Both adaption and reason needed for the mark, any two from:
Sperm has a streamlined/pointed head to help it swim /penetrate the egg.
It has very little cytoplasm so it can swim faster.
The head produces a chemical to help it penetrate the egg. / 3 /
10 / Cell / Surface area (mm2) / Volume (mm3) / Surface area: volume ratio
A / 100 / 1000 / 1:10
B / 6.25 / 15.63 / 1:2.5
Cell B because it has a smaller volume compared to surface area. / 8 /
Qu No / Answer / Marks / Level and guidance
11 / Any three from:
  • Small cells have a larger ratio (than larger cells)/ratio decreases as size increases.
  • Surface area/membrane must be large enough to absorb the nutrients/oxygen/substances needed.
  • Surface area/membrane must be large enough to excrete/pass out waste products.
  • Cell size is limited by SA/volume ratio
  • cells divide when they reach a certain size.
  • Any reference to diffusion across/through membrane/surface area.
/ 3 /
12 /
One mark for both shapes correct; one mark for nucleus in one cell only. / 2 /

Six-mark question

Marks / Requirement / Level and guidance
1–2 / For two marks, answers should include a simple reference to two of these ideas:
  • Preparing a slide using a thin slice of onion.
  • Putting the slide under the microscope.
  • Turning the focus knob to see the cell.
/ At this level, the quality of the English communication impedes the description or explanation of the science.
3–4 / In addition to the above, for a further two marks, answers should make reference to at least two of these applied ideas:
  • Adding a stain to the onion.
  • Using a cover slip to protect the microscope.
  • Identifying risks from the glass slide or scalpels.
/ At this level, the meaning of the English communication is clear but the quality of spelling and punctuation is not. The description or explanation of the science may be impeded.
5–6 / In addition to the above, for a further two marks, answers should apply and synthesise knowledge from other areas of science to make reference to at least two of these applied ideas:
  • Identifying the main parts of the microscope including the stage, course and fine focus knobs.
  • Identifying and reducing risks.
  • Identifying that there are different magnifications that will increase the level of detail observed.
/ At this level, the meaning of the English communication is clear, punctuation and spelling are correct, and sentences are formed from linked phrases.