Cell Level Systems | OCR GCSE Combined Science Biology, Foundation tier (J250)
Cell Level Systems
- 181 questions
- 9 subtopics
- Paper 1 (Biology)
- Paper 1 (Biology)
Cell Level Systems is examined in Paper 1 (Biology).
It covers microscopy, and sub-cellular structures, dNA structure: polymer, double helix and nucleotides, enzyme action, and investigating enzymes, cellular respiration as an exothermic process, aerobic and anaerobic respiration compared, synthesis and breakdown of carbohydrates, proteins and lipids, photosynthesis: producers and the process, photosynthesis as endothermic, and investigating it and limiting factors in photosynthesis.
Sample questions from Cell Level Systems
Answer each one closed book first, then open the answer.
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Microscopy, and sub-cellular structures
What is a plasmid, and which kind of cell contains one?
Show the answer
A small ring of DNA separate from the main genetic material, found in bacterial cells. -
DNA structure: polymer, double helix and nucleotides
Give one example of a biological polymer other than DNA.
Show the answer
Starch, or a protein. -
Enzyme action, and investigating enzymes
What does the lock and key hypothesis describe?
Show the answer
The substrate fits into the active site as a key fits a lock, so only a matching substrate can bind. -
Cellular respiration as an exothermic process
Name three processes in an organism that depend on the ATP supplied by respiration.
Show the answer
Muscle contraction, active transport and the building of large molecules such as proteins. -
Aerobic and anaerobic respiration compared
Which substrate is broken down in both aerobic and anaerobic respiration?
Show the answer
Glucose. -
Synthesis and breakdown of carbohydrates, proteins and lipids
What happens when a protein is broken down?
Show the answer
The chain is split back into its individual amino acids. -
Photosynthesis: producers and the process
Why would almost all life on Earth end if photosynthesis stopped?
Show the answer
No new food or biomass would be made and the oxygen used up in respiration would not be replaced. -
Photosynthesis as endothermic, and investigating it
How can the rate of photosynthesis of pondweed be measured?
Show the answer
By counting the bubbles of oxygen released, or by collecting and measuring the volume of gas produced in a set time.
The 9 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Microscopy, and sub-cellular structures | The parts of a light microscope and preparing and staining slides, calculating magnification, where genetic material and plasmids sit in plant, animal and bacterial cells, the jobs of mitochondria, chloroplasts, the membrane and its receptors, and ribosomes, resolution and what electron microscopes revealed, converting between millimetres, micrometres and nanometres in standard form, estimating cell sizes, and significant figures. | 30 |
| DNA structure: polymer, double helix and nucleotides | What a polymer is, why DNA is a polymer built from nucleotides, how monomers and polymers differ, how the chain is built, and the two strands twisted into a double helix and why that shape stores genetic information stably. | 14 |
| Enzyme action, and investigating enzymes | Measuring the rate of an enzyme reaction with amylase and catalase, controlling pH and temperature, the active site and lock and key model, and how temperature, pH and concentration change the rate. | 31 |
| Cellular respiration as an exothermic process | What cellular respiration and ATP are, why respiration is universal and continuous, the processes that depend on its ATP, the mitochondrion, how respiration differs from breathing, why it is exothermic, the germinating seeds experiment and its control, and how respiration keeps mammals and birds warm, heats the body in exercise and warms a compost heap. | 16 |
| Aerobic and anaerobic respiration compared | The word equations for aerobic and anaerobic respiration, their difference in oxygen and ATP yield, the products in yeast and muscle, lactic acid and fatigue, and yeast in bread and brewing. | 14 |
| Synthesis and breakdown of carbohydrates, proteins and lipids | How glucose builds starch and glycogen and why they are stored and broken down, amino acids as the monomers of proteins and why about twenty of them give so many proteins, the roles of proteins, lipids built from fatty acids and glycerol and broken down by lipase, why lipids store energy and their other uses, and the Benedict's, biuret and emulsion food tests. | 30 |
| Photosynthesis: producers and the process | Why photosynthetic organisms are the main producers of biomass, algae and phytoplankton as producers, where the carbon and energy in consumers come from, why life depends on photosynthesis and food chains start with producers, the word equation, chloroplasts and chlorophyll, where the reactants come from, the two stages, and what happens to the glucose made. | 16 |
| Photosynthesis as endothermic, and investigating it | Endothermic reactions and where the energy in photosynthesis ends up, how it compares with respiration, measuring the rate in pondweed with a lamp, and testing a leaf for starch to show light is needed. | 22 |
| Limiting factors in photosynthesis | How light intensity, carbon dioxide concentration and temperature each change the rate of photosynthesis, why the rate stops rising in very bright light and falls when too hot, why growers heat, light and burn fuel in greenhouses, and slow photosynthesis on a cold bright day. | 8 |
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.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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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.
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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.
Nearby topics
OCR GCSE Combined Science Biology, Foundation tier Active Recall Guide
Every topic, not just this one. 806 questions with their answers.