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.
Baculovirus is a virus that kills some of the insect pests of major crops. When the virus is released to the outside of the insect body, it is cont...
Barlinka is a variety of the common grapevine, Vitis vinifera. Barlinka grapes are used for making wine and are sold as fruit. There are economic a...
The causative organism of measles is Morbillivirus. Young children who have not been vaccinated for measles are at highest risk of becoming ill and...
Amylase is an enzyme that catalyses the hydrolysis of starch into reducing sugars. A student carried out an experiment to investigate the hydrolysi...
Fig. 1.1 is a diagram showing a stage in protein synthesis. [Figure 1.1]
Pepsin is an enzyme that hydrolyses proteins (protease). Some students used pepsin from the stomach of a mammal. The activity of the pepsin was inv...
Fig. 3.1 is a transmission electron micrograph showing red blood cells in a capillary of a healthy adult. [Figure 3.1]
In thale cress, Arabidopsis thaliana, most of the stomata are on the lower surface of the leaves. Fig. 4.1 is a diagram of an open stoma and two gu...
Measles is a highly infectious disease. The World Health Organization (WHO) has coordinated a programme for controlling this disease by using vacci...
(a) Table 6.1 compares some of the features of DNA with the protein collagen. Complete Table 6.1. [Table 6.1]
Fig. 1.1 is a diagram of a kidney nephron and some of its blood vessels.
Cotton, Gossypium hirsutum, and false flax, Camelina sativa, are crop plants that are grown in different parts of the world. Rubisco activase is an...
Ecological surveys are conducted before conservation decisions are made. For example, surveys can be carried out before deciding whether to reintro...
In 1984, the geneticist Alec Jeffreys invented a DNA testing technique, known as DNA profiling, that produces a DNA banding pattern on a gel. The D...
Gibberellin is a plant growth regulator involved in barley seed germination. Production of gibberellin is stimulated by the uptake of water. State ...
Fig. 6.1 outlines the first three stages of respiration in aerobic conditions. [Figure 6.1]
The function of the enzyme iduronate 2-sulfatase is to break down certain complex molecules. Hunter syndrome is a rare, inherited condition in huma...
California salamanders are terrestrial amphibians. An original population of California salamanders occupied an area of forest in northern Californ...
The Bowman's capsule of a nephron is involved in ultrafiltration. Fig. 1.1 is a diagram of part of a Bowman's capsule and glomerulus. [Figure 1.1] ...
Scientists are researching new ways to reduce the global atmospheric carbon dioxide (CO2) concentration. There are concerns that an increasing atmo...
During the germination of barley seeds, amylase is produced.
Genome-wide association studies find links between single nucleotide polymorphisms (SNPs) and phenotypic features such as human diseases. SNPs are ...
Biodiversity can be considered at three different levels. Fig. 5.1, Fig. 5.2 and Fig. 5.3 are images that show these three different levels of biod...
ATP is needed for many metabolic processes in living organisms. [Figure 6.1]
The Labrador is a variety of domestic dog. Labradors have fur that can be brown, black or yellow. In Labradors, TYRP1 is one gene that codes for fu...
Twenty million years ago, an ocean covered the area where the country of Panama is now located. There was a gap between the continents of North Ame...
Describe the roles of ADH and the collecting ducts in osmoregulation.
Fig. 1.1 is a diagram of a kidney nephron and some of its blood vessels. [Figure 1.1]
Baker's yeast, Saccharomyces cerevisiae, has two metabolic pathways for the production of ATP, aerobic respiration and fermentation. Oxygen is not ...
Species diversity is often used as a simple way to compare the biodiversity of different regions of the world. A student read that species diversi...
Some students researched how yeast, Saccharomyces cerevisiae, is used in the food industry. The students found that in different manufacturing proc...
Fig. 2.1 shows a gray tree frog, Dryophytes versicolor. [Figure 2.1] Males of this species make a very distinctive mating call. Some male gray tre...
The diagram shows a stage micrometer, with divisions 0.10mm apart, viewed through an eyepiece containing a graticule. [Diagram] The area of the fie...
Where are cisternae found in a cell? 1 endoplasmic reticulum 2 Golgi body 3 mitochondria
Which row matches the functions to the cell structures?
Which structures are found in prokaryotes and eukaryotes?
Which molecules are present in all viruses? 1 thymine 2 adenine 3 cytosine
The table shows the observations recorded from tests for biological molecules on four samples, A, B, C and D. Which conclusion is correct?
The diagrams show some biological molecules. [Diagrams A, B, C, D] Which biological molecule forms a polymer with a structural role in plants?
Which molecule is a disaccharide and a reducing sugar?
The diagram shows bonding in part of a polysaccharide. [Diagram] Which type of glycosidic bond is shown at position X?
Which statements about triglycerides and phospholipids are correct? 1 Fatty acids in a triglyceride may be saturated or unsaturated but in a phosph...
Silk moth caterpillars have been genetically modified to produce a mixture of their own silk and the much stronger spider silk of the golden orb we...
Which property of the tertiary structure of a globular protein enables it to catalyse a metabolic reaction?
A student investigated the effect of substrate concentration on the activity of an enzyme. The graph shows the results of this investigation. [Grap...
The Michaelis–Menten constant, Km, is the substrate concentration at which an enzyme works at half its maximum rate. What is correct when the Km va...
Which functions are performed by glycoproteins on the surface of a cell surface membrane? 1 to act as enzymes catalysing reactions in the membrane ...
The diagram represents a process by which molecules move out of a cell through a cell surface membrane. [Diagram] Which process does this represent?
Which processes that occur in the cell cycle are represented in the diagram? [Graph]
A gene codes for the production of a protein, p53, that binds to damaged DNA during interphase and prevents its replication. A carcinogen in cigare...