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.
Measurements of the stem of a young tree showed that the diameter varied slightly. It decreased during the day and increased during the night. Whic...
Which statement about the human circulatory system is correct?
The graph shows changes in the volume of the ventricles during the cardiac cycle. [Figure 32.1 - graph showing changes in ventricular volume during...
Haemoglobin can bind to carbon dioxide, carbon monoxide and oxygen. 1 carbon dioxide, 2 carbon monoxide, 3 oxygen Which gases share a binding site?
A good gas exchange system maintains a steep diffusion gradient, has a large total surface area and a short diffusion distance. Which feature of th...
Which statement about bronchioles is correct?
In which regions of the human gas exchange system is the function of some types of cell directly affected by tar in cigarette smoke?
What is the causative agent and method of transmission of smallpox? [Figure 37.1 - table of causative agent and transmission method for smallpox]
A scientist investigated the effect of an antibiotic on the treatment of cholera. 320 people suffering with cholera were split into two groups. One...
Which sequence of events occurs during an immune response? 1 development of plasma cells, 2 mitosis of B-lymphocytes, 3 recognition of non-self ant...
An influenza vaccine can be made by growing the viruses in chicken eggs. The viruses are extracted in liquid from the eggs and inactivated. The pur...
Fig. 1.1 is a photomicrograph of plant cells showing stages in cell division.
Fig. 2.1 is a transmission electron micrograph of a section through a blood vessel. Fig. 2.2 is a graph showing how the blood pressure in the pulmo...
Cells of the immune system function to protect the body against infectious diseases.
Fig. 4.1 shows the structure of the R groups of three amino acids, aspartate (Asp), glutamine (Gln) and isoleucine (Ile).
Fig. 5.1 is a transmission electron micrograph of part of a cell.
Plants have two transport tissues, xylem and phloem. Fig. 6.1 shows root hair cells.
The root apical meristem is a region of undifferentiated cells in the root tips of plants. Mitosis occurs in this region.
Triglycerides and phospholipids are types of lipid. Fig. 2.1 shows the structure of one type of phospholipid known as phosphatidylcholine. F1 and F...
Hydrolytic enzymes can function within the cell or can be secreted by the cell, where they are able to catalyse reactions.
Fig. 4.1 is a transmission electron micrograph of the bacterium that causes cholera, Vibrio cholerae. The flagellum shown in Fig. 4.1 allows moveme...
Descriptions A, B and C relate to the movement of water from the soil to the xylem in roots.
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...
Describe how the structure of a mitochondrion is related to its function.
Explain how meiosis can lead to genetic variation.