Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Cholera and tuberculosis are infectious diseases that can spread when people have to live in overcrowded conditions. Which strategies would help co...
Immunity to certain pathogens develops when a person is given a vaccination. Which effects of vaccination are correct? 1 production of antibodies t...
A student wrote three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are protein molecules...
Fig. 1.1 is a transmission electron micrograph showing a section of a human liver cell. [Figure 1.1]
Fig. 2.1 is a simplified diagram of the human circulatory system. [Figure 2.1]
Carbonic anhydrase is a globular protein found in red blood cells.
Scientists have produced structures known as virosomes, which are used in certain vaccines. Virosomes do not cause disease. Fig. 4.1 is a diagram o...
When water molecules enter a plant through the roots, the molecules cross the cortex and enter the xylem tissue to be transported to other parts of...
Fig. 6.1 is a photomicrograph of plant cells in stages of the mitotic cell cycle. [Figure 6.1]
The mammalian circulatory system is adapted for the long-distance transport of the respiratory gases, oxygen and carbon dioxide. The system is desc...
Human cytomegalovirus (HCMV) is a common virus affecting humans. In people with a fully functioning immune system, infection by HCMV usually causes...
Plasmodium falciparum is one species of Plasmodium that causes the life-threatening disease malaria. With early diagnosis and the correct drug trea...
The airways of the gas exchange system are lined with epithelium. Gradual changes in the structural features of this epithelium occur as the airway...
Fibroblasts are one of the cell types of connective tissue. The cells synthesise and secrete collagen, which forms part of the supporting external ...
Xylem and phloem are the transport tissues of plants. Both tissues have more than one cell type. The conducting cells of xylem contain xylem sap an...
During translation, a polypeptide is synthesised when amino acids are added to a growing chain of amino acids. Fig. 1.1 shows part of a growing cha...
Fig. 2.1 is a scanning electron micrograph showing a macrophage engulfing some bacteria. [Figure 2.1]
Students investigated the relationship between two environmental factors and the rate of cavitation in a Scots pine tree, Pinus sylvestris, over a ...
The early development of an animal involves divisions of the zygote and daughter cells by mitosis to form an embryo consisting of genetically ident...
Cathelicidin LL-37 is a cell signalling compound that stimulates many different cells in humans. One role of cathelicidin LL-37 is stimulating the ...
Fig. 6.1 shows some of the events that occur when a red blood cell flows through a capillary in the lungs. [Figure 6.1]
Some fruit contains large quantities of ascorbic acid (vitamin C). Ascorbic acid can be absorbed through the partially permeable wall of the gut. ...
You are provided with a solution labelled E containing an enzyme which coagulates (clots) milk. Enzyme E hydrolyses (breaks) peptide bonds between ...
The wild Bactrian camel, Camelus ferus, lives only in the desert regions of Mongolia and northern China. Fig. 1.1 shows a wild Bactrian camel. [Fig...
Photosynthesis is an important energy transfer process.
(a) The results of investigations carried out on mitochondria show how the structure of a mitochondrion is related to its role in aerobic respirati...
Adenosine deaminase (ADA) deficiency is an immune system disorder caused by a recessive autosomal mutation. Severe combined immunodeficiency caused...
A large number of alpine plant species grow in the mountains of New Zealand's South Island. Alpine plants are defined as plants that live above the...
Selective breeding has been used to improve the characteristics of crop plants, including maize and rice.
(a) In some varieties of domestic cats the gene for fur colour is located on the X chromosome. This gene has two alleles. One allele codes for blac...
(a) A neuromuscular junction allows the transmission of an action potential from a motor neurone to a striated muscle fibre, causing it to contract...
The passage below outlines homeostasis. Complete the passage by using the most appropriate scientific terms. Homeostasis, in mammals, is the proces...
The Asiatic lion, Panthera leo persica, is found only in the Gir Forest National Park in the Gujarat region of western India. Fig. 1.1 shows a fema...
Yeast cells can respire in anaerobic conditions. Bioethanol is a type of biofuel produced from maize starch on an industrial scale. In the high tem...
Photosynthesis is an energy transfer process that takes place in chloroplasts of plant cells. [Figure 3.1, Figure 3.2]
Haemophilia is a blood clotting disorder in humans caused by a mutant allele on the X chromosome. Table 4.1 compares two forms of haemophilia: haem...
Myosotis is a genus of small flowering plants. Many different Myosotis species grow on the islands of New Zealand, which are an important site of M...
The lac operon of prokaryotes contains a group of structural genes that are under the same control and are transcribed together. Another operon fou...
The determination of sex in domestic turkeys is different from that in humans. The sex chromosomes in turkeys are named Z and W. Male turkeys are Z...
Selective reabsorption takes place in the proximal convoluted tubule of a kidney nephron. Fig. 8.1 is a diagram of two cells of the proximal convol...
Voltage-gated channels are involved in the generation of an action potential. Fig. 9.1 is a diagram of the voltage-gated channels of sodium ions an...
Glucagon has a role in the maintenance of blood glucose concentration. Fig. 10.1 shows the relationship between blood glucose concentration and blo...
(a) Fig. 8.1 is a diagram of a kidney nephron. [Figure 8.1] [Figure 8.2]
Antibiotic resistance in bacteria is a global problem that has caused scientists to research into antibacterial substances other than antibiotics. ...
Holstein cattle have been selectively bred for their high milk production. The seed of the cotton plant, Gossypium spp. is a good source of fibre,...
Egg albumen (egg white) is a good source of protein. Some eggs contain up to 10.0% w/v (100gdm-³) protein. A biuret assay can be used to determine...
A main feature of Huntington's disease (HD) is a loss of neurones from a region of the brain known as the striatum. A study of brain tissue taken f...
Holstein cattle have been selectively bred for their high milk production. The seed of the cotton plant, Gossypium spp. is a good source of fibre, ...
The diagram shows an electron micrograph of virus particles in a human nucleus. [Figure 2.1] What is the diameter of the labelled virus particle?