Edexcel International GCSE Biology 4BI1: Use of biological resources – Practice Questions

These are original questions written for Marlbridge, for revision and practice on this content. They are not reproduced past-paper questions, and they do not replicate the exam’s exact structure, question count or mark tariffs – examination boards hold copyright in their own papers. Use these alongside the official past papers from your board or school.

These questions cover Topic 5, Use of biological resources (points 5.1–5.20), of the Pearson Edexcel International GCSE Biology (4BI1) specification, Issue 3, for the June and November series examined under Issue 3. The course is untiered and a calculator may be used on both papers. Questions 9 and 12 test bold B statements and are labelled “Paper 2 only”.

Learn the content first in the study guide and the revision notes. The course hub is Edexcel IGCSE Biology and the printable checklist lists every point.

Questions

1. Describe how growing strawberries in a polythene tunnel can increase their yield. [3]

2. A grower keeps a tomato glasshouse at 20 °C and changes the carbon dioxide concentration.

CO₂ concentration (parts per million)	400	800	1200
Yield (kg per m²)	30	39	40

(a) Calculate the percentage increase in yield when the CO₂ concentration rises from 400 to 800 parts per million. [2] (b) Explain why increasing the CO₂ concentration increases the yield. [2] (c) Suggest why the yield hardly changes between 800 and 1200 parts per million. [1] (d) On a hot day the ventilation fails and the temperature rises to 45 °C. Predict and explain the effect on yield. [2]

3. Explain why a farmer adds nitrate fertiliser to a field that has grown wheat every year. [3]

4. Whitefly are insect pests of glasshouse tomatoes. A grower can spray a pesticide or release a small wasp that parasitises whitefly. Discuss the advantages and disadvantages of each method. [6]

5. Explain why bread dough containing yeast is left in a warm place before baking. [3]

6. A student investigates the effect of temperature on anaerobic respiration in yeast. She collects gas in a gas syringe for 4 minutes at each temperature.

Temperature (°C)	20	30	40	60
Volume of gas (cm³)	6.0	14.0	23.2	3.2

(a) Calculate the rate of gas production at 40 °C. Give the unit. [2] (b) Explain why the rate at 60 °C is the lowest. [2] (c) Give two variables she should keep the same. [2] (d) State why she pours a layer of oil on the yeast and sugar mixture. [1]

7. Describe how yoghurt is made from milk using Lactobacillus. [4]

8. Explain the need for each feature of an industrial fermenter.

(a) Steam sterilisation before use, and filtered air. [2] (b) A water jacket. [2] (c) Motor-driven paddles. [2]

9. (Paper 2 only) Explain how a fish farmer can maximise the amount of fish protein produced in a tank. [5]

10. Describe how a farmer could use selective breeding to produce cattle with a high milk yield. [4]

11.

(a) State what is meant by the term transgenic. [1] (b) Describe how bacteria can be genetically modified to produce large amounts of human insulin. [5] (c) Give two ways genetically modified plants can improve food production. [2]

12. (Paper 2 only)

(a) Describe how micropropagation is used to produce new orchid plants. [3] (b) Give one advantage of micropropagation to a commercial grower. [1] (c) Describe how Dolly the sheep was produced. [3] (d) Explain how cloned transgenic animals can be used to produce human proteins. [2]

Answers

1. Traps heat, so it is warmer and photosynthesis (enzyme activity) is faster [1]; protects plants from frost, wind or rain [1]; plants can be grown earlier or for a longer season [1] Examiner insight: “Plants grow better” earns nothing; each mark needs a named condition linked to its effect.

2. (a) (39 − 30) ÷ 30 × 100 [1] = 30% [1] (b) Carbon dioxide is a reactant in photosynthesis and was limiting [1]; more glucose is made, which is used for growth [1] (c) Another factor, such as light intensity or temperature, is now limiting [1] (d) Yield decreases [1]; enzymes controlling photosynthesis are denatured above their optimum [1] Examiner insight: In (a), dividing by 39 instead of 30 loses the answer mark; the method mark needs the original value on the bottom.

3. Harvesting removes mineral ions from the soil each year [1]; nitrate ions are needed to make amino acids and proteins [1]; so plants grow more and yield increases [1] Examiner insight: “Fertiliser feeds the plant” is not credited; name the ion and what it is used to make.

4. Pesticide acts quickly on the whitefly [1]; but it can kill non-target insects, such as pollinators [1]; and whitefly may become resistant, so repeated spraying is needed [1]; the wasp targets only whitefly [1]; and leaves no chemical residue on the tomatoes [1]; but it is slow and does not remove all the whitefly [1] Examiner insight: Six-mark “discuss” answers are marked for a balance of points; covering one method only limits the mark however many points you give.

5. Yeast respires anaerobically, producing carbon dioxide [1]; the gas is trapped as bubbles, so the dough rises [1]; warmth brings yeast enzymes nearer their optimum, so respiration is faster [1] Examiner insight: Naming ethanol as the gas that raises the dough is a wrong statement and cancels the respiration mark.

6. (a) 23.2 ÷ 4 [1] = 5.8 cm³ per minute [1] (b) Enzymes in the yeast are denatured [1]; so less respiration occurs and less carbon dioxide is released [1] (c) Mass of yeast [1]; volume and concentration of sugar solution [1] (d) To stop oxygen reaching the yeast, so respiration is anaerobic [1] Examiner insight: The unit is part of the answer mark in (a); a bare “5.8” does not get full credit where the question asks for a unit.

7. Milk is heated (pasteurised) to kill other bacteria, then cooled [1]; Lactobacillus is added and the mixture is incubated warm [1]; the bacteria ferment lactose into lactic acid [1]; the pH falls, so milk proteins clot and the yoghurt thickens [1] Examiner insight: A correct sequence scores more reliably than a list; each stage needs its reason (why heat, why acid).

8. (a) Kills contaminating microorganisms [1]; which would compete for nutrients or produce unwanted or toxic products [1] (b) Respiration releases heat, and cool water removes it [1]; keeping enzymes at their optimum temperature so they do not denature [1] (c) Mixes the contents [1]; so nutrients, oxygen and heat are evenly spread to all microorganisms [1] Examiner insight: Each part is one “what” mark and one “why” mark; describing the feature alone caps each part at 1.

9. Keep fish of different sizes in separate tanks to prevent intraspecific predation [1]; use nets to keep out predators such as birds (interspecific predation) [1]; keep water oxygenated and filter out waste [1]; control disease with antibiotics or by avoiding overcrowding [1]; give high-protein food little and often, so none is wasted and growth is fast [1] Examiner insight: Use the technical terms correctly; describing “intraspecific” predation as other species eating the fish is a contradiction and scores zero for that point.

10. Choose a cow with a high milk yield and a bull whose mother had a high yield [1]; breed them together [1]; select the female offspring with the highest milk yield and breed from them [1]; repeat over many generations [1] Examiner insight: “Repeat over many generations” is a separate mark and is often left out.

11. (a) Genetic material transferred from one species to a different species [1] (b) The human insulin gene is cut out with a restriction enzyme [1]; a plasmid is cut with the same restriction enzyme, giving matching sticky ends [1]; ligase joins the gene into the plasmid [1]; the recombinant plasmid is taken up by bacteria [1]; the bacteria are grown in a fermenter, multiply and make insulin, which is extracted [1] (c) Pest resistance, so less crop is lost [1]; drought tolerance or herbicide resistance, so yield rises [1] Examiner insight: Stating that ligase “cuts” or restriction enzymes “join” is a contradiction; the mark for that step is lost even if the rest is right.

12. (a) Small pieces (explants) are cut from the tips of the parent plant [1]; placed on sterile agar containing nutrients and plant hormones [1]; they grow into plantlets, which are transferred to compost [1] (b) Many genetically identical plants with the desired features are produced quickly [1] (c) The nucleus is removed from an egg cell of one sheep [1]; a diploid nucleus from a body (udder) cell of another sheep is inserted, and an electric shock makes it divide [1]; the embryo is implanted into a surrogate sheep; the lamb is identical to the nucleus donor [1] (d) A human gene is inserted into an animal embryo, so the animal makes the human protein, for example in its milk [1]; the transgenic animal is cloned to give many animals that all make the protein [1] Examiner insight: In (c), “a nucleus” without “diploid” or “from a body cell” is too vague to credit the second marking point.

Where marks are usually lost

• Writing “better conditions” instead of naming heat, CO₂ or protection.
• Forgetting that yield levels off because another factor becomes limiting.
• Percentage change calculated using the new value as the denominator.
• Rates given without a unit.
• Treating ethanol as the gas that raises bread.
• Describing fermenter parts without saying why each is needed.
• Missing “same restriction enzyme” and “ligase” in GM descriptions.
• Confusing intraspecific and interspecific predation.
• Saying Dolly is identical to the egg donor or surrogate.

Next steps

• Recap with the revision notes.
• Reread any weak section in the study guide.
• Browse other topics on the Edexcel IGCSE Biology hub.
• Track coverage with the printable checklist.
• Try all free 10-minute diagnostics.
• Book a free trial class.

Official syllabus

Pearson Edexcel International GCSE in Biology (4BI1) specification, Issue 3, first examination June 2019, Pearson Education Limited – Topic 5, Use of biological resources.