Edexcel GCSE Combined Science Biology, Higher tier sample questions and answers (1SC0)
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45 sample questions and answers
Taken from every topic of Edexcel GCSE Combined Science Biology, Higher tier, specification 1SC0. The full guide has 968.
Paper 1, Paper 2
Key Concepts in Biology
147 questions in the guide, across 9 subtopics. More from this topic
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Eukaryotic and prokaryotic cells
Explain why muscle cells contain very large numbers of mitochondria.
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Mitochondria are the site of aerobic respiration, and contracting muscle needs a large and continuous supply of energy. -
Specialised cells and their adaptations
Explain why the nucleus of a sperm cell is haploid.
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It carries only one set of chromosomes, so that fertilisation restores the full number rather than doubling it. -
Microscopes and magnification calculations
Explain how improvements in microscope technology have changed our understanding of cells.
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Greater magnification and resolution revealed organelles that were previously invisible, which allowed scientists to work out what each one does. -
Size, scale and units in cell biology
What does the prefix micro mean, and which unit is used for measuring most cells?
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Micro means 10⁻⁶, and cells are usually measured in micrometres. -
Enzyme action and denaturation
Why is the mechanism of enzyme action described as a lock and key model?
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Only one substrate fits the active site, in the same way that only one key fits a particular lock.
Paper 1
Cells and Control
76 questions in the guide, across 5 subtopics. More from this topic
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Mitosis and the cell cycle
Where do the chromosomes move to during metaphase?
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They line up across the middle of the cell, attached to spindle fibres. -
Mitosis and the cell cycle
What does it mean to say a body cell is diploid?
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It contains two copies of every chromosome, which is 23 pairs in a human body cell. -
Why mitosis matters: growth, repair and cancer
Why are offspring produced by asexual reproduction genetically identical to their parent?
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They are made by mitosis, which produces cells with exactly the same chromosomes as the parent cell. -
Why mitosis matters: growth, repair and cancer
What sort of change inside a cell can lead to cancer?
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A change in the genes that normally control how often the cell divides. -
Growth, differentiation and percentile charts
In which parts of an animal's body does cell division take place during growth?
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Throughout the body, rather than only in special growth regions as in a plant.
Paper 1
Genetics
111 questions in the guide, across 9 subtopics. More from this topic
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Meiosis and the formation of gametes
How does the chromosome number of a cell made by meiosis compare with that of the parent cell?
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Each daughter cell has half the number of chromosomes of the parent cell. -
DNA structure, genes and the genome
What type of bond holds a pair of bases together across the two strands?
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Weak hydrogen bonds hold each base pair together. -
Extracting DNA from fruit
Why is salt added to the mixture when extracting DNA from fruit?
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The salt makes the DNA molecules stick together so they can be seen. -
Alleles, genotype and phenotype
What is a chromosome?
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A chromosome is a long, coiled molecule of DNA found in the nucleus that carries many genes. -
Monohybrid crosses and sex determination
A homozygous dominant parent is crossed with a homozygous recessive parent. Describe the genotypes and phenotypes of the offspring.
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All the offspring are heterozygous and all show the dominant characteristic.
Paper 1
Natural Selection and Genetic Modification
73 questions in the guide, across 7 subtopics. More from this topic
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Natural selection and antibiotic resistance
Explain how natural selection can eventually give rise to a new species.
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If two populations become separated and face different conditions, different alleles are selected in each until the two groups can no longer breed together to give fertile offspring. -
Natural selection and antibiotic resistance
Name one antibiotic-resistant bacterium that causes difficult infections in hospitals.
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MRSA, a strain of Staphylococcus aureus that is resistant to methicillin. -
Fossil evidence for human evolution
How old is the fossil skeleton known as Lucy, and which species does it belong to?
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It is about 3.2 million years old and belongs to Australopithecus afarensis. -
Fossil evidence for human evolution
How old is Turkana Boy, and which species does the skeleton belong to?
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It is about 1.6 million years old and belongs to Homo erectus. -
Stone tool evidence for human evolution
Describe the stone tools being made about 300 000 years ago.
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Flint was worked into a wider range of shaped tools, including pointed flakes used as spear tips, scrapers and knives.
Paper 1
Health, Disease and the Development of Medicines
126 questions in the guide, across 9 subtopics. More from this topic
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Health, disease and susceptibility
Describe the difference between a communicable and a non-communicable disease.
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A communicable disease can be passed from one organism to another, while a non-communicable disease cannot be transmitted. -
Pathogens and common infections
What is a protist?
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A protist is a single-celled eukaryotic organism, and some kinds live as parasites that cause disease. -
How pathogens spread, and the virus life cycle
Explain how the spread of tuberculosis can be reduced.
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Infected people can be isolated and treated, and less crowded, well-ventilated buildings make breathing in the bacteria less likely. -
Sexually transmitted infections
Explain why Chlamydia is often passed on without the infected person realising.
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Many people who have it show no symptoms, so they do not know they are infected and continue to pass it on. -
Physical barriers and chemical defences
Describe the role of cilia in the airways.
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Cilia beat to sweep mucus and the pathogens trapped in it up to the throat, where it is swallowed.
Paper 2
Plant Structures and Their Functions
104 questions in the guide, across 6 subtopics. More from this topic
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Photosynthesis as an endothermic reaction
Explain why animals depend on photosynthetic organisms for their food.
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Animals cannot make their own food, so they must obtain it by eating producers or by eating other animals that ate producers. -
Photosynthesis as an endothermic reaction
Name the pigment that absorbs light for photosynthesis and state where it is found.
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Chlorophyll, which is held inside the chloroplasts of plant and algal cells. -
Limiting factors in photosynthesis
Explain why the rate of photosynthesis falls sharply above about 45 °C.
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The enzymes controlling photosynthesis denature, so their active sites change shape and can no longer catalyse the reactions. -
Limiting factors in photosynthesis
The rate of photosynthesis is measured against light intensity at 15 °C and at 25 °C. Explain why the line for 25 °C levels off at a higher rate.
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At the higher temperature the enzymes work faster, so photosynthesis can reach a greater rate before another factor becomes the one in short supply. -
Light intensity and the rate of photosynthesis
Describe two ways of improving the quality of results in an investigation of light intensity and photosynthesis.
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Repeat each distance at least three times and calculate a mean, and collect the gas in a capillary tube so its volume can be measured precisely.
Paper 2
Animal Coordination, Control and Homeostasis
112 questions in the guide, across 7 subtopics. More from this topic
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Hormones, endocrine glands and homeostasis
Which organ lying behind the stomach releases hormones that control blood glucose?
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The pancreas. -
Hormones, endocrine glands and homeostasis
Name three conditions inside the body that are kept constant.
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Body temperature, the concentration of glucose in the blood, and the water content of the blood. -
Adrenalin, thyroxine and negative feedback
Which organ does adrenalin act on to raise blood sugar, and what conversion does it cause there?
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The liver, where stored glycogen is converted into glucose that passes into the blood. -
Adrenalin, thyroxine and negative feedback
Which part of the brain responds to a fall in thyroxine, and what does it release?
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The hypothalamus responds, and it releases TRH. -
The menstrual cycle and its hormones
Which hormone causes the lining of the uterus to thicken, and where is it made?
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Oestrogen, which is made in the ovaries.
Paper 2
Exchange and Transport in Animals
115 questions in the guide, across 9 subtopics. More from this topic
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Why multicellular organisms need exchange surfaces
State why mineral ions must be transported to cells.
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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.
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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.
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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.
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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.
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The pulmonary artery.
Paper 2
Ecosystems and Material Cycles
104 questions in the guide, across 8 subtopics. More from this topic
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Levels of organisation and interdependence
Place the terms community, individual organism, ecosystem and population in order from the smallest level of organisation to the largest.
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Individual organism, then population, then community, then ecosystem. -
Abiotic and biotic factors in a community
Explain why few plants grow on the floor of a dense woodland.
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The tree canopy absorbs most of the light, so plants below cannot photosynthesise fast enough to grow well. -
Parasitism and mutualism
Explain why a flea is described as a parasite.
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It feeds on its host's blood, gaining food while causing the host irritation and possible infection. -
Sampling with quadrats and transects
What is a belt transect?
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A belt transect is a line laid across a habitat along which quadrats are placed to record how the species present change with distance. -
Estimating population size from field data
Twenty quadrats, each of area 0.25 m², contain 60 buttercup plants altogether. Calculate the mean number of buttercups per square metre.
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The quadrats cover 20 × 0.25 = 5 m², so the mean is 60 ÷ 5 = 12 buttercups per m².
Edexcel GCSE Combined Science Biology, Higher tier Active Recall Guide
The other 923 questions, with the answers printed after each section.