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.
The enzyme carbonic anhydrase has been found in a wide range of organisms and acts as a catalyst in many tissues. Studies have shown that there are...
Fig. 5.1 is a photomicrograph of a transverse section through part of the bronchus of the human gas exchange system. The image is of a good resolut...
The transport tissues of plants are phloem and xylem. The role of xylem is the transport of water and mineral ions from the soil solution to the di...
The trachea of the gas exchange system branches into two airways, each of which enters a lung.
Bacterial cells are prokaryotic. The cells of plants are described as eukaryotic.
Hakea spp. are xerophytic plants native to Australia. The leaves of Hakea have adaptations for a xerophytic mode of life.
There are many different forms of Vibrio cholerae, a bacterium that is found naturally in aquatic environments. The bacterium is motile (can move) ...
Arachidonic acid is a fatty acid that is a common component of phospholipids. Phospholipids can be used as a source of arachidonic acid when it is...
The sinoatrial node, atrioventricular node and the Purkyne tissue have important roles in the cardiac cycle.
Plant extracts contain molecules which have many uses in industry and as medicines. It is important for scientists to be able to estimate the conce...
Plant tissues contain the enzyme catalase which catalyses the breakdown of hydrogen peroxide into oxygen gas and water. Ascorbic acid acts as an in...
K1 is a slide of a stained transverse section through a plant stem.
Plant cells contain an enzyme which catalyses the breakdown of hydrogen peroxide, releasing oxygen, as shown in Fig. 1.1. enzyme hydrogen peroxide ...
L1 is a slide of a stained transverse section through a plant leaf. Fig. 2.1 shows an image of some epidermal cells from the surface of a different...
(a) The golden mantella, Mantella aurantiaca, is a small terrestrial frog found in Madagascar. [Figure 1.1]
In eukaryotes, the cells of plants and photosynthetic protoctists contain chloroplasts.
Respiration is a process that results in the synthesis of ATP. The ATP can be used within the cell for energy-requiring reactions and processes. Th...
In 1973 a technique for genetic engineering was used for the first time. Recombinant DNA was made using a plasmid and this was successfully transfe...
Two subspecies of reindeer, Rangifer tarandus, live in North America. Members of the different subspecies belong to the same species but have some ...
In mammals, the blood glucose concentration must be maintained within narrow limits so that the body cells can function efficiently. Name the mecha...
(a) The fruit fly, Drosophila melanogaster, usually has red eyes. A gene for eye colour has four alleles: red, apricot, honey and white. Define the...
(a) Over the past 200 years, many species of animals and plants have become extinct. [Figure 8.1] Key ---- number of species x----x human population
Stomata are involved in both transpiration and photosynthesis in plants. [Figure 9.1] Complete Table 9.1 by choosing the correct letter from Fig. 9...
(a) Motor neurones and sensory neurones have different roles in nervous coordination. Contrast the structure and function of sensory neurones and m...
The jaguar, Panthera onca, is a large cat that lives mainly in South America. The majority of jaguars have light brown fur with black spots, as sho...
(a) Photosynthesis is affected by many environmental factors.
Aerobic respiration occurs when oxygen is available. A much greater energy yield is obtained from aerobic respiration than from respiration in anae...
In 1973, a technique for genetic engineering was used for the first time. Recombinant DNA was made using a plasmid and this was successfully transf...
Bison are a type of large wild cattle. Ancestors of modern bison appeared in Asia 2.5 million years ago. This ancestral bison species increased its...
(a) Gibberellin is a plant hormone that has an important role in seed germination. [Figure 6.1] is a diagram of a section through a barley seed (gr...
The bacterium, Escherichia coli, can use glucose or disaccharides, such as lactose, in its metabolism. Lactose needs to be hydrolysed by the enzyme...
The role of sensory receptor cells in mammals is to detect stimuli and generate action potentials in sensory neurones. Human taste buds on the tong...
(a) Ultrafiltration in the kidney takes place between the glomerulus and the Bowman's capsule. The afferent blood vessel carrying blood to the glom...
The African penguin, Spheniscus demersus, lives along the coast of South Africa. [Figure 10.1] shows two African penguins.
(a) The water potential of mammalian blood needs to be maintained within narrow limits so that cells function efficiently. This process is called o...
Photosynthesis is an energy transfer process that results in the production of carbohydrate. It has two stages: the light-dependent stage and the l...
ATP is synthesised from ADP and Pᵢ in a phosphorylation reaction.
The puma, Puma concolor, lives in North and South America. [Figure 5.1] shows a puma. [Figure 5.2] shows the distribution of the puma species.
(a) Epistasis occurs when a gene at one locus can affect the expression of a gene at another locus.
(a) The Malayan tapir, Tapirus indicus, lives in the rainforest of South East Asia. [Figure 8.1] shows a Malayan tapir and her calf. On the Interna...
(a) [Figure 9.1] shows a cross-section through a myelinated neurone.
(a) Insulin has an important role in the maintenance of blood glucose concentration. An investigation measured how blood glucose concentration and ...
A group of students investigated two habitats: dense woodland and open grassland. • Trees are the dominant plants in woodland. The trees form a can...
Human immunodeficiency virus (HIV) is an example of a virus that spreads from other animals to humans where it causes disease. [Figure 2.1] shows a...
Fig. 1.1 A shows the root vegetable beetroot, Beta vulgaris. Fig. 1.1 B shows a single cell from the beetroot tissue. The vacuole contains the red...
The European badger, Meles meles, pictured in Fig. 2.1, is a mammal found in England. Badgers can contract bovine tuberculosis (bTB) caused by the...
There are a variety of methods used to estimate the water potential of plant tissues.
Respiration in blowfly larvae, Calliphora erythrocephala, can be studied by determining the respiratory quotient (RQ). A student used the apparatus...
A graticule and a micrometer scale can be used to measure the size of biological structures that are viewed with a microscope. [Figure 1.1] Which r...
Six organelles found in eukaryotic cells are shown. [Figure 2.1] Which organelles are involved in the synthesis and secretion of a glycoprotein?