Home › Free Resources › Biology Worksheets › GCSE / IGCSE Biology – Cell Biology
Free Biology Worksheet

GCSE / IGCSE Biology – Cell Biology

Cell structure, microscopy, division, transport.

WhatsApp Mr. AhmadBook a trial lesson (50% off)Free worksheets
12 questions  ·  48 marks  ·  answers included  ·  GCSE/IGCSE Biology (Edexcel/AQA/Cambridge style)
Download the PDFAsk about a question

This worksheet covers:

  • This worksheet covers cell structure
  • Microscopy and magnification calculations
  • Cell division
  • Transport across membranes (diffusion, osmosis and active transport)

A calculator is required for the magnification and percentage-change calculations. Allow about 40 minutes.

Questions

Section A – Cell structure and microscopy (skills)

1

State the function of each of the following subcellular structures:(a) nucleus(b) mitochondria(c) ribosomes(d) cell membrane

Show answer
(a) Contains the genetic material (DNA) and controls the activities of the cell.(b) The site of (aerobic) respiration, releasing energy for the cell.(c) The site of protein synthesis (translation).(d) Controls the movement of substances into and out of the cell.
[4]
2

A student draws a scale diagram of a cell. The image width on the drawing is $45\,\text{mm}$, and the actual width of the cell is $15\,\mu\text{m}$.Calculate the magnification of the drawing, using $\text{magnification} = \dfrac{\text{image size}}{\text{actual size}}$.

Show answer
Convert to the same units: $45\,\text{mm} = 45000\,\mu\text{m}$.$\text{magnification} = \dfrac{45000}{15} = 3000$ (i.e. $\times 3000$)
[3]
3

A photograph of a cell has a magnification of $\times 400$. The image width measured on the photograph is $60\,\text{mm}$.Calculate the actual width of the cell, giving your answer in $\mu\text{m}$.

Show answer
$\text{actual size} = \dfrac{\text{image size}}{\text{magnification}} = \dfrac{60\,\text{mm}}{400} = 0.15\,\text{mm} = 150\,\mu\text{m}$
[3]
4

List, in the correct order, the four stages of mitosis, giving one key event that occurs in each stage.

Show answer
Prophase: chromosomes condense and become visible; the nuclear envelope breaks down.Metaphase: chromosomes line up individually along the equator (middle) of the cell.Anaphase: sister chromatids are pulled apart to opposite poles of the cell by spindle fibres.Telophase: chromatids reach the poles and uncoil; a nuclear envelope reforms around each set, followed by division of the cytoplasm.
[4]

Section B – Transport and specialised cells (exam-style)

5

A cylinder of potato tissue has an initial mass of $5.20\,\text{g}$. After being placed in a concentrated sugar solution for 30 minutes, its mass is $4.83\,\text{g}$.(a) Calculate the percentage change in mass, giving the sign of your answer.(b) Explain, in terms of osmosis, why the mass changed in this way.

Show answer
(a) $\dfrac{4.83-5.20}{5.20}\times100\% = -7.1\%$ (a decrease of $7.1\%$, to 2 s.f.)(b) The sugar solution had a lower water potential than the potato cells. Water moved out of the potato cells, across the partially permeable cell membranes, by osmosis (from a region of higher water potential inside the cells to a region of lower water potential in the solution), causing the cells to lose water and the tissue to lose mass.
[4]
6

Define diffusion, osmosis and active transport, and for each give one example of where it occurs in the human body or a plant.

Show answer
Diffusion: the net movement of particles from a region of higher concentration to a region of lower concentration, down a concentration gradient, e.g. the diffusion of oxygen from air in the alveoli into the blood.Osmosis: the net movement of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane, e.g. water moving from soil into root hair cells.Active transport: the movement of particles from a region of lower concentration to a region of higher concentration (against the concentration gradient), using energy from respiration, e.g. mineral ions being absorbed into root hair cells from a dilute soil solution.
[6]
7

Give three structural differences between a typical plant cell and a typical animal cell.

Show answer
Any three, e.g.: (1) Plant cells have a cell wall made of cellulose; animal cells do not. (2) Plant cells often have a large, permanent vacuole filled with cell sap; animal cells have only small, temporary vacuoles (if any). (3) Plant cells contain chloroplasts (for photosynthesis); animal cells do not. Plant cells are also usually a fixed, regular shape, while animal cells can vary in shape.
[3]
8

Root hair cells are adapted for the efficient absorption of water and mineral ions from the soil.Describe two features of a root hair cell that adapt it for this function, explaining how each feature helps.

Show answer
Any two, e.g.: (1) A long, thin extension (the root hair) that greatly increases the surface area in contact with the soil, increasing the rate of diffusion/osmosis of water and ions into the cell. (2) A large number of mitochondria, providing the energy (ATP) needed for the active transport of mineral ions against their concentration gradient. (3) A large permanent vacuole, which maintains a steep water potential gradient, increasing the rate of osmosis.
[4]

Section C – Extended and calculation (challenge)

9

Stem cells are undifferentiated cells that can divide to form specialised cells.(a) Explain what is meant by ‘differentiation’.(b) Give one medical use of stem cells, and one ethical concern associated with the use of embryonic stem cells.

Show answer
(a) Differentiation is the process by which an unspecialised (stem) cell becomes adapted for a specific function, developing specific structures related to its role (e.g. becoming a nerve, muscle or blood cell).(b) Medical use: e.g. treating certain blood disorders (such as some cancers) using bone-marrow stem cell transplants, or research into growing replacement tissues/organs. Ethical concern: e.g. obtaining embryonic stem cells usually involves the destruction of a human embryo, which some people believe is morally wrong.
[4]
10

A single cell divides by mitosis every 24 hours.(a) Calculate how many cells will be present after 5 divisions, starting from a single cell.(b) Calculate the minimum number of hours required for the population to reach at least 500 cells.

Show answer
(a) Number of cells $= 2^5 = 32$(b) $2^9 = 512 \geq 500$ (since $2^8 = 256 < 500$), so 9 divisions are needed: $9 \times 24 = 216\,\text{hours}$
[4]
11

The rate of diffusion into a cell depends on its surface area to volume ratio (SA:V).(a) Calculate the surface area to volume ratio of a cube-shaped cell of side length $2\,\text{mm}$.(b) Calculate the surface area to volume ratio of a cube-shaped cell of side length $4\,\text{mm}$.(c) Use your answers to explain why larger organisms cannot rely on diffusion alone to supply all their cells with oxygen and nutrients.

Show answer
(a) $\text{SA:V} = \dfrac{6(2)^2}{(2)^3} = \dfrac{24}{8} = 3 : 1$(b) $\text{SA:V} = \dfrac{6(4)^2}{(4)^3} = \dfrac{96}{64} = 1.5 : 1$(c) As size increases, surface area to volume ratio decreases (from 3:1 to 1.5:1 here). Since diffusion occurs across the surface but nutrients/oxygen are needed by the whole volume, a lower SA:V ratio means diffusion alone becomes too slow to supply the interior of a large organism, which is why larger organisms need specialised exchange surfaces and transport systems (e.g. lungs and a circulatory system).
[5]
12

A student prepares a slide of onion epidermal cells to view under a light microscope.(a) Describe how the student should prepare the slide, including the use of a stain.(b) The microscope is used with an eyepiece lens of magnification $\times 10$ and an objective lens of magnification $\times 40$. Calculate the total magnification used.

Show answer
(a) Peel a thin layer of epidermal tissue from the inner surface of an onion; place it flat on a microscope slide with a few drops of water; add a drop of stain (e.g. iodine solution) to increase the contrast/visibility of cell structures such as the nucleus; carefully lower a cover slip on top at an angle (using a mounted needle) to avoid trapping air bubbles.(b) Total magnification $= 10 \times 40 = \times 400$
[4]

Related worksheets

More worksheets in GCSE & IGCSE Biology:

GCSE / IGCSE Biology – Organisation and PhysiologyGCSE / IGCSE Biology – Infection and ResponseGCSE / IGCSE Biology – BioenergeticsGCSE / IGCSE Biology – Inheritance and EvolutionGCSE / IGCSE Biology – Ecology

All biology worksheets  ·  Full resource library  ·  Biology tuition with Mr. Ahmad

Get new biology worksheets by email

One short email when new worksheets are added. No spam, unsubscribe any time.



    Book a trial lesson (50% off)

    Try a full first lesson with Mr. Ahmad at 50% off before you commit to anything. It is a real lesson, not a sales call: bring a topic the student is stuck on and we will work through it together.

    • Online from anywhere in the world, or in person across Dubai
    • You get honest feedback on where the student stands and what to fix first
    • No contract — if it is not the right fit, that is fine

    Prefer to talk? Message on WhatsApp and you will hear back within 24 hours.



      Stuck on this topic?

      Book a trial lesson with Mr. Ahmad at 50% off and bring this worksheet with you — online worldwide or in person in Dubai.

      WhatsApp nowBook a trial lesson (50% off)
      Scroll to Top