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.
There is a lot of epidemiological evidence linking smoking to disease and early death. Which is the best description of 'epidemiological'?
Which row shows the effects of chronic bronchitis?
A country had fewer than 2.5 deaths per 100 000 people from TB in one year and the next year this rose to 25 deaths per 100 000. What may have cont...
A graft of tissue, such as skin, from a different person is usually rejected by the body. Which statement about graft rejection is correct?
The diagram shows a simplified nitrogen cycle. [Figure 38.1] Which row shows the correct labels for P, Q, R and S?
Which statements about energy flow in ecosystems are correct? 1 All energy eventually leaves ecosystems in the form of heat. 2 The average energy t...
In many freshwater ecosystems, the availability of inorganic nitrogen compounds is a limiting factor for growth. This means that producers cannot g...
At approximately which magnification is light microscopy not suitable because the resolution becomes too low?
The diagram shows a stage micrometer viewed with an eyepiece graticule scale, using a magnification of ×400. [Figure 2.1] Using the same magnificat...
Which organelle does not contain a partially permeable membrane?
The diagram shows an electron micrograph of a plant cell. [Figure 4.1] What do structures X, Y and Z contain?
An amino acid enters a cell and is then used to synthesise an enzyme secreted by the cell. What is the sequence of cell structures involved in the ...
The diagram shows some similarities between chloroplasts, mitochondria and prokaryotes. [Figure 6.1] Which row is correct?
Which shows the basic unit of glycogen?
Four sugar solutions were tested with Benedict's solution. The table shows the colour of the solutions after testing. [Table 8.1] What is the best ...
Which features adapt a cellulose molecule for its function? 1 Long chains of glucose molecules coil into a helix. 2 Many hydrogen bonds form betwee...
The structure of phospholipids and triglycerides include the following. 1 glycerol linked to fatty acids 2 hydrophobic fatty acid chains 3 saturate...
Which molecule contains a glycosidic bond?
The diagrams show the structures of two amino acids, each of which has two carboxylic acid (-COOH) groups. [Figure 12.1] A peptide bond is formed b...
The drug ritonavir is sometimes used in the treatment of HIV/AIDS. Ritonavir consists of three amino acids and is a competitive inhibitor of HIV pr...
The diagram shows the fluid mosaic model of a section of a cell surface membrane. [Figure 14.1] What is the role of each of the components labelled...
Proteins in the cell surface membranes of human cells and mouse cells were labelled with red and green fluorescent dyes respectively. When a human ...
The diagram shows a plant cell. [Figure 16.1] The plant cell is put into a solution with a water potential less negative than the cell contents. Wh...
The cell cycle includes mitosis. Which are features of nuclear division? 1 forms cells of equal size to the parent cell 2 forms genetically identic...
Which is the correct statement concerning cell and nuclear division?
Diploid (2n) organisms that reproduce sexually produce haploid (n) gametes. Some plants, such as wheat, can produce diploid or haploid gametes. The...
Which nucleic acid bases are pyrimidines?
What is the correct sequence for the processes involved in the formation of an enzyme in a cell?
A short piece of DNA fifteen base pairs long was analysed to find the number of nucleotides in each of the polynucleotide strands. Some of the resu...
The diagram represents part of the phloem pathway, with adjacent cells, from leaves to the root of a plant. [Figure 24.1] Which process is occurrin...
Which xerophytic adaptations reduce the water potential gradient? 1 rolled leaves 2 hairy leaves 3 sunken stomata 4 fewer stomata 5 fleshy leaves
What is not a factor influencing blood pressure?
Which of the following are found in blood and lymph and tissue fluid? 1 carbon dioxide 2 fatty acids 3 white blood cells 4 proteins
The graph shows the percentage saturation of haemoglobin with oxygen at different partial pressures of oxygen and two different concentrations of c...
Some babies are born with a hole between the right and left atria. These babies have an increased number of red blood cells. What is the reason for...
In the lungs, oxygen and carbon dioxide pass through cell membranes by diffusion. Which row is correct?
Which describes how substances in cigarette smoke increase the risk of developing atherosclerosis? 1 Carbon monoxide damages the endothelium of the...
Which flow diagram correctly describes the effect of tar entering the lungs?
Which could directly reduce the surface area available for gas exchange in human lungs? 1 emphysema 2 lung cancer 3 smoking
The malarial parasite, Plasmodium, infects red blood cells and breaks down haemoglobin. Free haem groups are toxic to Plasmodium and the parasite c...
During a primary immune response, the following events occur. 1 Some B-lymphocytes form plasma cells. 2 B-lymphocytes with the specific cell surfac...
Which statement concerning the defence in the body against infectious disease is not correct?
An antiserum to a snake toxin can be obtained by injecting the toxin into a horse. The antiserum is made from blood plasma taken from the horse a f...
The flow of nutrients in an ecosystem is shown in the diagram. [Figure 38.1] Which letter represents decomposers?
An insect eats only the leaves of grass. This insect is eaten by carnivorous beetles. Which ecological terms are described in this information abou...
A gardener has a waterlogged garden showing poor growth. He decides to drain it in an attempt to reduce the numbers of some harmful bacteria. Which...
What is the diameter of a typical plant cell?
A specimen is viewed under a microscope using green light with a wavelength of 510 nm. If the same specimen is viewed under the same conditions, bu...
What is the function of plasmodesmata in plant cells?
Which size of ribosome is found in both chloroplasts and mitochondria?