Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Complete hydrolysis of polysaccharides requires all the glycosidic bonds between the monomers to be broken. Enzyme X only breaks α-1,4 glycosidic b...
Which molecules contain at least two double bonds?
The diagram shows an amino acid. [Figure showing a generic amino acid structure] Which group is changed to produce different amino acids?
Which row is correct about the structure of proteins? [Table describing primary, secondary, tertiary, and quaternary protein structures]
Which graph correctly shows possible changes in energy levels as a chemical reaction progresses with or without an enzyme? [Four graphs (A, B, C, D...
The graph shows the relationship between the concentration of substrate and the rate of an enzyme-catalysed reaction. [Figure showing a graph of ra...
Liver cells contain vesicles that have proteins in their membranes which are specific for the transport of glucose. When these cells need to take u...
A student set up an experiment to investigate diffusion. A block of agar, 1.0 cm × 1.0 cm × 1.0 cm, was stained uniformly with a water-soluble blue...
Which description is correct?
During metaphase, a scientist stains the chromosomes of a diploid animal cell with fluorescent dye to allow the telomeres to be observed. This cell...
The photomicrographs show cells in various stages of the cell cycle. [Figure showing four photomicrographs labeled 1, 2, 3, 4, depicting cell cycle...
Uncontrolled cell division can result in the formation of a tumour. Which part of the cell cycle would take less time during the formation of a tum...
A piece of a DNA molecule contains 84 base pairs. The table shows the number of adenine and cytosine bases in one or both of the DNA strands in thi...
The mRNA sequences of the three stop codons are shown. UAA UAG UGA Which mutation in the template (transcribed) strand of a DNA sequence that codes...
Which features of companion cells are essential to their function? 1 They are connected to the sieve tube elements by plasmodesmata. 2 They have a ...
Which statements about water movement in plants are correct? 1 Water can pass through cellulose cell walls. 2 Water cannot pass through lignified c...
Which sequence of events could lead to mass flow in a phloem sieve tube? 1 Sucrose moves into a sieve tube element. 2 Protons (H+) and sucrose mole...
What will happen as a result of the blood pressure in the right ventricle becoming higher than the blood pressure in the right atrium?
Which statements are correct? 1 Compared with blood, tissue fluid has less protein and no red blood cells. 2 Lymph may contain lipids, carbon dioxi...
What explains how the maximum volume of oxygen is taken up as blood passes through the capillaries of the lungs?
The image shown is a photomicrograph of a transverse section of part of the gas exchange system. [Figure showing a photomicrograph] What describes ...
When a person suffers an asthma attack, the tubes of the gas exchange system narrow and extra mucus is produced. Which changes occur during an asth...
Which flow diagram correctly describes the effect of tar entering the lungs? [Four flow diagrams (A, B, C, D) describing a sequence of events]
Which control measures would reduce the transmission of tuberculosis (TB)? [Table with boiling water before drinking it, antibiotics, vaccination]
Comorbidity is where an individual has two or more diseases or medical conditions at the same time. Some medical conditions are particularly likely...
Which conditions are infectious and result in a high white blood cell count? 1 leukaemia 2 myasthenia gravis 3 TB
Which cell type causes the secondary immune response to be much faster than the primary immune response?
Fig. 1.1 is a transmission electron micrograph of cells from the leaf of a plant. [Figure 1.1]
Fig. 2.1 is a transmission electron micrograph of a transverse section through a blood capillary that is surrounded by actively respiring cells. [F...
Cholera is an infectious disease caused by the bacterial pathogen Vibrio cholerae. (a) Describe how V. cholerae is transmitted from an infected per...
Fig. 4.1 is a drawing made by a student of a plant cell, showing one of the stages of mitosis. [Figure 4.1]
A student investigated the effects of air movement on the rate of transpiration by using a potometer.
Fig. 6.1 is a diagram of sections through the heart showing two stages of the cardiac cycle, A and B. [Figure 6.1]
There are two types of cell, prokaryotic and eukaryotic. Bacterial cells are prokaryotic and plant cells are eukaryotic.
The high blood pressure at the arterial end of a capillary network results in some components of blood leaving the capillaries and forming tissue f...
Baculovirus is a virus that kills some of the insect pests of major crops. When the virus is released to the outside of the insect body, it is cont...
Barlinka is a variety of the common grapevine, Vitis vinifera. Barlinka grapes are used for making wine and are sold as fruit. There are economic a...
The causative organism of measles is Morbillivirus. Young children who have not been vaccinated for measles are at highest risk of becoming ill and...
Amylase is an enzyme that catalyses the hydrolysis of starch into reducing sugars. A student carried out an experiment to investigate the hydrolysi...
Fig. 1.1 is a diagram showing a stage in protein synthesis. [Figure 1.1]
Pepsin is an enzyme that hydrolyses proteins (protease). Some students used pepsin from the stomach of a mammal. The activity of the pepsin was inv...
Fig. 3.1 is a transmission electron micrograph showing red blood cells in a capillary of a healthy adult. [Figure 3.1]
In thale cress, Arabidopsis thaliana, most of the stomata are on the lower surface of the leaves. Fig. 4.1 is a diagram of an open stoma and two gu...
Measles is a highly infectious disease. The World Health Organization (WHO) has coordinated a programme for controlling this disease by using vacci...
(a) Table 6.1 compares some of the features of DNA with the protein collagen. Complete Table 6.1. [Table 6.1]
Fig. 1.1 is a diagram of a kidney nephron and some of its blood vessels.
Cotton, Gossypium hirsutum, and false flax, Camelina sativa, are crop plants that are grown in different parts of the world. Rubisco activase is an...
Ecological surveys are conducted before conservation decisions are made. For example, surveys can be carried out before deciding whether to reintro...
In 1984, the geneticist Alec Jeffreys invented a DNA testing technique, known as DNA profiling, that produces a DNA banding pattern on a gel. The D...