Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Fig. 6.1 is a diagram of a vertical section through the mammalian heart. The labels Q to X represent valves and blood vessels of the heart. [Figure...
Fig. 1.1 is a transmission electron micrograph of a part of an animal cell. [Figure 1.1]
Fig. 2.1 shows the heart and blood vessels at three stages of the cardiac cycle. [Figure 2.1]
Fig. 3.1 shows the structure of an alveolus and surrounding structures in a mammalian lung. The lining of each alveolus is formed by two types of e...
Malaria is a disease transmitted by a vector. In 2014, the World Health Organization (WHO) estimated that 3200 million people were at risk of malar...
The tree species Caryocar brasiliense grows in areas where there is very little rainfall for five months of the year. During this long dry season t...
Extracellular growth factors are involved in the control of cell cycles in some mammalian cells. One of these growth factors is epidermal growth fa...
Some plants store starch as grains. Some starch grains have rings on the surface and the grains from different plant types differ in size and shape...
Plant cells contain enzymes that catalyse metabolic reactions. Some of these enzymes catalyse the release of oxygen from hydrogen peroxide. A plant...
The St. Lawrence river in Canada has been identified as an area with very high biodiversity. (a) Explain how the term biodiversity can be considere...
The light dependent stage of photosynthesis in a suspension of isolated chloroplasts can be investigated using the Hill reaction. Dichlorophenolind...
[Figure 3.1] shows a red squirrel, Sciurus vulgaris. This species is native to the British Isles, meaning it has lived there for at least 10000 yea...
There are many different strains of the soil bacterium Bacillus thuringiensis. It produces slightly different types of Cry-proteins, which are toxi...
(a) Explain the importance of the myelin sheath in the transmission of action potentials. (b) Acetylcholine is a neurotransmitter. Describe the eve...
Chemiosmosis is the term used to describe the synthesis of ATP using a proton gradient across a membrane in a mitochondrion or chloroplast. It was ...
(a) Galactosaemia is a rare genetic disease in which the build-up of the monosaccharide galactose can result in an enlarged liver, kidney failure a...
(a) Homeostasis in mammals involves negative feedback mechanisms. Outline how a negative feedback mechanism works. (b) [Figure 8.1] is a diagram su...
(a) Explain how rice is adapted to grow with its roots submerged in water. (b) Explain how the leaves of maize or sorghum are able to maximise carb...
(a) Describe the types of gene mutation that can occur and explain how some mutations can lead to a shortened polypeptide. (b) Outline the effects ...
Fig. 1.1 shows a snow leopard, Panthera uncia. The habitat of the snow leopard is the high mountains of Central Asia. [Figure 1.1] Snow leopards us...
Fig. 3.1 shows a male red deer, Cervus elaphus. Red deer are herbivores, browsing on low vegetation in forests and on waste land. [Figure 3.1] A hi...
The body temperature of a human is maintained at its set point of approximately 37°C. If it rises above this temperature, physiological responses b...
Huntington's disease is caused by a dominant allele of the gene that codes for the production of the huntingtin protein. This protein affects the d...
Cloves are the aromatic flower buds of the tree Syzygium aromaticum. Eugenol is a drug extracted from cloves. Eugenol affects the movement of sodiu...
In respiration, most ATP is synthesised during oxidative phosphorylation. Some ATP is made by substrate-linked reactions in glycolysis and Krebs cy...
The sweet pea, Lathyrus odoratus, is a flowering plant that grows in many parts of Europe. The inheritance of flower colour and shape of pollen gra...
The St. Lawrence river in Canada has been identified as an area with very high biodiversity. (b) The St. Lawrence river is rich in species of aquat...
Fig. 3.1 shows a red squirrel, Sciurus vulgaris. This species is native to the British Isles, meaning it has lived there for at least 10000 years. ...
Galactosaemia is a rare genetic disease in which the build-up of the monosaccharide galactose can result in an enlarged liver, kidney failure and b...
Fig. 8.1 is a diagram summarising the role of the nervous and endocrine systems in the control of blood glucose concentration. hypothalamus neurone...
The enzyme urease catalyses the breakdown of urea into carbonate ions and ammonium ions as shown in Fig. 1.1. urease urea + water --[urease]--> car...
Barley is often grown in soils that are high in salt (sodium chloride). Researchers tested the salt tolerance of two varieties of barley, X and Y, ...
The enzyme lactase hydrolyses the disaccharide lactose to glucose and galactose. This enzyme is produced in the small intestine of mammals and by s...
In some countries crops are irrigated using water containing salt (sodium chloride). This makes the soil saline (salty) which means it contains suf...
What is the diameter of a typical prokaryote, such as Streptococcus?
A specimen of plant tissue is first observed under a microscope using red light with a wavelength of 650 nm. The same specimen is then observed und...
Which structures are present in a Vibrio cholerae cell?
The removal of a plant cell wall by enzyme digestion leaves an intact membrane-bound structure called a protoplast. Which statement explains why pr...
Which statements are correct for a green plant? 1 ATP is produced by mitochondria. 2 ATP is produced by chloroplasts. 3 ATP forms part of the DNA.
Which processes occur in eukaryotes and prokaryotes? 1 hydrolysis 2 mitosis 3 transcription 4 translation
A sample of a solution was tested for reducing sugar and the result was negative. Another sample of the same solution was then tested for non-reduc...
Which row correctly identifies three polysaccharides
Which diagram shows where a peptide bond would be formed?
Which statements about collagen molecules are correct? 1 Both types of secondary structure occur within the molecules. 2 Large numbers of hydrogen ...
The protein glutenin gives bread dough its elasticity. The diagram represents a polypeptide of glutenin. What describes the structure of glutenin?
Which diagram correctly shows hydrogen bonding between water molecules? The symbol δ indicates the partial charge on an atom in the water molecule.
Aspirin inhibits an enzyme by reacting with an amino acid that forms an essential part of the 3D structure of the enzyme. Part of the aspirin molec...