Cell Biology | AQA GCSE Biology, Higher tier (8461)

Cell Biology

202 questions
13 subtopics
Paper 1
Paper 1

Cell Biology is examined in Biology Paper 1.

It covers eukaryotes and prokaryotes, animal and plant cells, cell specialisation and differentiation, microscopy, growing bacteria and aseptic technique, calculating bacterial growth, and testing antiseptics and antibiotics, chromosomes, mitosis and the cell cycle, stem cells in embryos, adults and meristems, therapeutic cloning, its risks, and cloning plants, diffusion and the factors affecting its rate, surface area to volume ratio and exchange surfaces, osmosis and active transport.

Sample questions from Cell Biology

Answer each one closed book first, then open the answer.

Eukaryotes and prokaryotes

What type of cell is a bacterial cell?

Show the answer
A prokaryotic cell.
Animal and plant cells

Describe how a slide of plant cells is prepared for viewing under a light microscope.

Show the answer
Place a thin piece of tissue on a slide, add a drop of stain, then lower a coverslip onto it at an angle to avoid trapping air bubbles.
Microscopy

Explain why an electron microscope can show structures a light microscope cannot.

Show the answer
Its higher resolving power lets two very close points be seen separately, so cells are shown in much finer detail.
Growing bacteria and aseptic technique

Why must Petri dishes and culture media be sterilised before they are used?

Show the answer
To kill any microorganisms already on them that would otherwise grow and contaminate the culture.
Chromosomes, mitosis and the cell cycle

Describe the order of events in the cell cycle.

Show the answer
The cell grows and copies its DNA, then the nucleus divides by mitosis, and finally the cytoplasm and membranes divide.
Stem cells in embryos, adults and meristems

Suggest why a patient who cannot make healthy blood cells may be given a bone marrow transplant.

Show the answer
The transplanted marrow contains stem cells that can differentiate into healthy blood cells.
Diffusion and the factors affecting its rate

Name two gases moved in and out of cells by diffusion during gas exchange.

Show the answer
Oxygen and carbon dioxide.
Surface area to volume ratio and exchange surfaces

How are the leaves of a plant adapted for exchanging gases?

Show the answer
They are broad and thin, giving a large surface area and a short diffusion path, with air spaces inside and pores in the surface.

The 13 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Eukaryotes and prokaryotes	The features shared by plant and animal cells, what makes a cell eukaryotic or prokaryotic, how bacterial DNA, plasmids and the cell wall are arranged, and sizes in standard form.	14
Animal and plant cells	The functions of the nucleus, cell membrane, mitochondria, chloroplasts, plasmids and ribosomes, the permanent vacuole and cellulose cell wall of plant cells, estimating sizes, preparing, staining, focusing and drawing a slide under a light microscope, total magnification, and reducing the risks from glass and stains.	18
Cell specialisation and differentiation	How ciliated, sperm, nerve, muscle, root hair, xylem and phloem cells suit their jobs, why differentiation matters, and when animal and plant cells differentiate.	15
Microscopy	Magnification and resolution, how electron microscopes compare with light microscopes and what they revealed about sub-cellular structures, and calculating magnification, image size and real size, including conversion to micrometres and standard form.	14
Growing bacteria and aseptic technique	Binary fission and how fast bacteria divide, growing bacteria in nutrient broth or as colonies on agar plates, why cultures must be uncontaminated, and aseptic technique, from sterilising dishes and flaming the inoculating loop to taping lids, storing plates upside down and incubating at 25 °C.	15
Calculating bacterial growth, and testing antiseptics and antibiotics	Colony and clear-zone areas from πr², bacterial numbers after a run of divisions in standard form, and the agar plate method, zones of inhibition and the control disc.	15
Chromosomes, mitosis and the cell cycle	Chromosomes, genes and why body cells hold them in pairs, the stages of the cell cycle from growth and DNA replication through mitosis to division of the cytoplasm, and why mitosis produces identical cells for growth, development and repair.	17
Stem cells in embryos, adults and meristems	What a stem cell is and what undifferentiated means, the roles of stem cells in embryos, adults and bone marrow, and what meristem tissue can become.	14
Therapeutic cloning, its risks, and cloning plants	Using stem cells to treat conditions such as diabetes and paralysis, therapeutic cloning and why its cells are not rejected, the risk of viral infection, ethical and religious objections, and cloning plants from meristem tissue to save rare species and grow identical crops.	13
Diffusion and the factors affecting its rate	The definition of diffusion and net movement, substances such as oxygen, carbon dioxide and urea that diffuse into and out of cells, and how concentration gradient, temperature and membrane surface area affect the rate.	13
Surface area to volume ratio and exchange surfaces	Why single-celled organisms rely on their outer surface, surface area to volume ratios of cubes, why large organisms need exchange surfaces and transport systems, adaptations of the small intestine, lungs, gills, roots and leaves, and the features that make exchange effective.	16
Osmosis	Osmosis and partially permeable membranes, plant tissue in pure water and sugar solution, percentage change in mass and water uptake, the potato cylinder method and its variables, accuracy, precision, repeatability and reproducibility, systematic, zero and random errors, gradients and y = mx + c, and a hypothesis.	25
Active transport	The definition of active transport and its energy supply from respiration, uptake of mineral ions by root hair cells and of sugar from the gut, and how active transport compares with diffusion and osmosis.	13

Cell Biology is 202 of the 1,475 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.