Cambridge & Pearson Edexcel Past Paper Questions
Browse 35,704 questions from Cambridge O-Level & A-Level and Pearson Edexcel IGCSE & IAL exams. Click any question to practice.
Glycogen is a polymer of glucose. Which description summarises its structure?
Which molecules contain C=O bonds? 1 amino acids 2 fatty acids 3 proteins
Which of the statements about polysaccharides can be used to describe both amylose and amylopectin? 1 contains 1,4 glycosidic bonds 2 contains 1,6 ...
Which carbohydrate gives a brick red colour when heated with Benedict's solution?
The diagram shows two molecules of glucose. Four possible bonding positions are labelled p, q, r, and s, and t, u, v, w. [Figure 11.1] When these t...
Which graph represents the changes in concentration of a substrate and its product in the same enzyme-catalysed reaction?
Glucose in urine can be detected using a biochemical test. When the end of a test strip, which is impregnated with the enzyme glucose oxidase, is d...
What is the role of cholesterol in the cell surface membrane?
The following are all processes by which substances can enter a cell. 1 endocytosis 2 facilitated diffusion 3 osmosis Which processes are passive?
The diagram shows the water potential of three adjacent plant cells. [Figure 16.1] In which directions will there be net movement of water by osmosis?
Each of the following events takes place during mitosis. 1 centromeres divide 2 chromatids move to opposite poles of the cell 3 chromosomes line up...
The diagram shows the cell cycle. [Figure 18.1] When radioactive nucleotides are supplied to dividing cells, at which point will they be incorporat...
What does the process of transcription require?
A peptide consists of ten amino acids of four different kinds. What is the theoretical minimum number of different tRNA molecules required to trans...
Which statements about tRNA structure are correct? 1 There is a binding site for the attachment of a specific amino acid, as well as a different bi...
Which statements describe why a large animal has had to evolve a transport system? 1 diffusion occurs slowly over long distances 2 it has a high ra...
Which row identifies the tissue that contains the Casparian strip and the molecule forming this strip?
Which of the following are included in the apoplast pathway? 1 living components 2 plant vacuoles 3 cell walls 4 xylem vessels
Which statement explains why the circumference (girth) of a tree is less in the middle of the day than at night?
Sucrose is transported in solution in the phloem of plants. Transport takes place from sources to sinks. The process depends on differences in hydr...
Which of the following are found in all blood vessels, lymph and tissue fluid? 1 carbon dioxide 2 glucose 3 white blood cells 4 antibodies
The diagram shows the Bohr effect. [Figure 28.1] What causes the shift from X to Y?
The graph shows the pressure changes in different areas of the left side of the heart during one cardiac cycle. [Figure 29.1] Which row shows the p...
The stroke volume is the volume of blood pumped by each contraction of a ventricle. The ventricular end-diastolic volume is the volume of blood in ...
Which component of tobacco smoke causes an increase in blood pressure?
Which statements about chronic obstructive pulmonary disease (COPD) are correct? 1 The patient coughs a lot, bringing up mucus. 2 The patient's sym...
What would be seen in a photomicrograph of the wall of the trachea?
To prevent a disease, dead bacteria may be injected into the body. What type of immune response is produced?
The graph shows the amount of antibody produced in response to an antigen. [Figure 35.1] From the graph, which statement is correct?
Which of the following two diseases are caused by viruses?
Cholera is no longer common in many countries. What is the reason for this?
The diagram shows a food web. [Figure 38.1] How many trophic levels are represented in the food web?
What is the role of decomposers in the nitrogen cycle?
Why could only 4% of the energy from sunlight be fixed by producers during photosynthesis?
A light microscope is used to observe two membranes that are 200 nm apart. How far apart are the membranes when the objective lens is changed from ...
The electronmicrograph is of a chloroplast. [Figure 2.1] The length of the chloroplast along the line shown is 80 mm. The actual length of the chlo...
The diagram below is drawn from an electronmicrograph of an animal cell. [Figure 3.1] Which represents the same cell, seen under a light microscope...
Which features enable an organism to be identified as a prokaryote? 1 cell wall 2 circular DNA 3 nucleus 4 ribosomes
The diagram shows an electronmicrograph of a typical animal cell. [Figure 5.1] What is the function of the membrane system labelled X?
An animal cell and a plant cell are placed in distilled water. The animal cell swells and bursts, while the plant cell swells but does not burst. W...
The R groups (side chains) of amino acids can be hydrophobic, hydrophilic, acidic or basic. The diagram shows four different amino acid R groups. [...
Which describes the emulsion test for the presence of lipids?
The structural formula of a carbohydrate molecule can be shown as: [Figure 9.1] Which of the molecules could be represented by this formula? 1 ribo...
The diagram shows part of a molecule of glycogen. [Figure 10.1] How does the molecule differ from a molecule of amylose?
Which molecules contain a carboxyl group? 1 amino acid 2 glycerol 3 saturated fatty acid 4 unsaturated fatty acid
The diameter of some atoms when they form bonds are given in the table. [Figure 12.1] The approximate length of the amino acid shown below was esti...
Which feature of water is least likely to affect the life of an animal in a tropical rain forest?
Two pairs of students each counted the number of bubbles of oxygen given off in an experiment investigating the effect of catalase from plant tissu...
When investigating the rate of reaction of the enzyme lipase on the hydrolysis of triglycerides, the pH must be maintained at an optimum to prevent...
Which of the following can increase the fluidity of the cell surface membrane? 1 single bonds between carbon atoms in the fatty acid chains 2 chole...