Exchange and Transport in Animals | Edexcel GCSE Combined Science Biology, Higher tier (1SC0)
Exchange and Transport in Animals
- 115 questions
- 9 subtopics
- Paper 2
- Paper 2
Exchange and Transport in Animals is examined in Paper 2, Biology 2.
It covers why multicellular organisms need exchange surfaces and transport systems, alveoli and gas exchange, the blood, arteries, veins and capillaries, the heart and the double circulation, aerobic and anaerobic respiration, investigating the rate of respiration with a respirometer, and cardiac output.
Sample questions from Exchange and Transport in Animals
Answer each one closed book first, then open the answer.
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Why multicellular organisms need exchange surfaces
State why mineral ions must be transported to cells.
Show the answer
Cells need mineral ions to build substances such as haemoglobin and to keep their chemical processes working. -
Alveoli and gas exchange
Explain how the thickness of an alveolus wall helps gas exchange.
Show the answer
The wall is only one cell thick, giving a very short diffusion distance so gases cross quickly. -
The blood and its components
Explain why a mature red blood cell has no nucleus.
Show the answer
Losing the nucleus leaves more room for haemoglobin, so the cell can carry more oxygen. -
Arteries, veins and capillaries
Explain how the narrow lumen of an artery suits its function.
Show the answer
A narrow lumen helps to keep the blood pressure high as blood is carried to the organs. -
The heart and the circulatory system
Name the vessel that carries blood from the heart to the lungs.
Show the answer
The pulmonary artery. -
Cellular respiration as an exothermic reaction
Explain why respiration must go on continuously.
Show the answer
Cells need a constant supply of energy for their processes, and released energy cannot be stockpiled. -
Aerobic and anaerobic respiration compared
State the word equation for anaerobic respiration in yeast.
Show the answer
Glucose → ethanol + carbon dioxide. -
Investigating the rate of respiration
In a respirometer investigation into the rate of respiration of small organisms, name two variables that must be kept the same.
Show the answer
The mass of organisms used and the length of time each reading is taken over.
The 9 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Why multicellular organisms need exchange surfaces | The oxygen, carbon dioxide, water, glucose, mineral ions and urea that must be transported in an organism, calculating surface area to volume ratios of cubes, and why single-celled organisms and flatworms rely on diffusion while large animals need exchange surfaces and transport systems. | 16 |
| Alveoli and gas exchange | Alveoli as the site of gas exchange, how their number, one-cell-thick walls, capillary network, moist lining and ventilation keep the diffusion of oxygen and carbon dioxide fast, and the two cell layers oxygen crosses into the blood. | 8 |
| The blood and its components | Red blood cells, haemoglobin and oxyhaemoglobin, their biconcave shape and lack of a nucleus, phagocytes and lymphocytes, plasma and what it carries, platelets and clotting, estimating cell numbers per cubic millimetre, and pie chart angles and percentages for the parts of a blood sample. | 17 |
| Arteries, veins and capillaries | Arteries, veins and capillaries and the direction each carries blood, and how the thick elastic walls and narrow lumen of arteries, the valves and wide lumen of veins, and the thin walls and dense networks of capillaries suit their functions. | 9 |
| The heart and the circulatory system | The four chambers of the heart and why their walls differ in thickness, the vena cava, pulmonary artery, pulmonary vein and aorta, valves, the route from the right atrium to the lungs, the double circulation, and the coronary arteries that supply the heart muscle. | 12 |
| Cellular respiration as an exothermic reaction | What happens in cellular respiration, why it is exothermic and continuous in every living cell, how its energy is used for muscle contraction, building large molecules, active transport and keeping mammals warm, and the two types of respiration. | 9 |
| Aerobic and anaerobic respiration compared | The word and balanced symbol equations for aerobic respiration in mitochondria, anaerobic respiration producing lactic acid in muscles and ethanol and carbon dioxide in yeast and plants, fermentation, why anaerobic respiration releases less energy, and why sprinters respire anaerobically and what happens to lactic acid. | 12 |
| Investigating the rate of respiration | Using a respirometer with germinating peas or woodlice, soda lime and a glass bead control, the variables, airtightness, settling time, errors and safety, calculating means, ranges and uncertainty, anomalous results and range bars, and treating small animals ethically. | 23 |
| Cardiac output, stroke volume and heart rate | Stroke volume, heart rate and cardiac output and the equation linking them, calculating each from the other two, working out heart rate from a pulse count, converting to cubic decimetres, and why cardiac output rises during exercise. | 9 |
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
Edexcel GCSE Combined Science Biology, Higher tier Active Recall Guide
Every topic, not just this one. 968 questions with their answers.