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.
Neutrase® is an enzyme that is used to hydrolyse proteins in solution. When the enzyme is mixed with a 2% protein solution the reaction mixture cha...
Meristematic tissue is found in the growing regions of plants, such as shoot tips. Meristematic cells have a similar role to stem cells in animals....
The mammalian circulatory system is described as a closed double circulation. Explain why it is called a closed and double circulation. closed d...
The DNA in the nucleus is known as nuclear DNA.
Fig. 1.1 is a photomicrograph of a low power image of part of the common sunflower, Helianthus annuus. Fig. 1.1 is a transverse section. [Figure 1.1]
Some tissues of the gas exchange system include cells that are able to produce and secrete mucins. Mucins are stored in vesicles in these cells, re...
Fig. 3.1 is a photomicrograph of human blood cells from a healthy individual who lives at sea level. The cells labelled C, D and E are white blood ...
The bacterium Vibrio cholerae is the causative organism of the infectious disease cholera. V. cholerae has structural features typical of all bacte...
Cells contain carbohydrates, proteins, lipids and nucleic acids. (a) Fig. 5.1 is a list of biological molecules, some of which are components of la...
Catalase is an enzyme that catalyses the breakdown of hydrogen peroxide, which is a waste product of cell metabolism. The reaction catalysed by cat...
Fig. 1.1 is a diagram showing the structure of a section of a DNA molecule. [Figure 1.1]
Fig. 2.1 is a photomicrograph showing a transverse section through a bronchus and the surrounding lung tissue. [Figure 2.1]
Cholera is an infectious disease caused by the bacterium Vibrio cholerae. The pathogen causes disease by disrupting the activity of the epithelial ...
Phloem sieve tube elements and xylem vessel elements are cells that are involved with the transport of substances in plants.
Fig. 5.1 is a photomicrograph of human blood cells that have been placed in a solution of sodium chloride. [Figure 5.1]
Fig. 6.1 is a diagram of a vertical section of the human heart and the associated blood vessels. [Figure 6.1]
J1 is a slide of a stained transverse section through a plant root. You are not expected to be familiar with this specimen. Use a sharp pencil for ...
Fusicoccin is a chemical that increases the sucrose concentration in phloem at the source. In this investigation you will be provided with a sample...
M1 is a slide of a stained transverse section through a plant organ. You are not expected to be familiar with this specimen.
Fig. 1.1 shows part of a cell in a growing region of a plant. [Figure 1.1]
The interpupillary distance (IPD) is the distance in millimetres between the centres of the pupils of the eyes. Fig. 2.1 shows how IPD is measured....
Some neurones in the brain produce a neurotransmitter known as dopamine. Parkinson's disease occurs when the neurones that produce dopamine die. A ...
The link reaction and Krebs cycle take place in the mitochondrion. The main stages of the link reaction and Krebs cycle are listed in Table 4.1. Th...
Researchers investigated the extent to which the founder effect and natural selection affected evolutionary change. Fig. 5.1 shows the brown anole ...
Maize, Zea mays, is an important food crop for human consumption and for feeding to animals. Two varieties of maize are MON810 and Justina. Justina...
Some people have a condition called diabetes. In type 1 diabetes the pancreas does not produce enough insulin. Fig. 7.1 shows the blood glucose con...
Table 8.1 shows the total number of plant species, the total number of insect species and the number of habitats in three areas, A, B and C. [Table...
(a) Explain what is meant by the term limiting factor and explain how knowledge of limiting factors is used to increase crop yields in glasshouses....
(a) Explain how a cholinergic synapse functions. (b) Describe how you would carry out an investigation into the effect of wavelength of light on th...
(a) Fig. 1.1 is an electron micrograph showing a cross-section of a myelinated neurone. [Figure 1.1] Name A and B. A B
Steelhead trout, Oncorhynchus mykiss, are fish that live in streams in North America. To increase the number of steelhead trout, captive breeding h...
Soybean, Glycine max, is an important food crop for human consumption and for feeding to animals. Two varieties of soybean are Vinton 81 and GTS 40...
Oculocutaneous albinism (OCA) is a type of albinism. There are many different forms of OCA. OCA1A is one form of OCA, caused by a recessive mutatio...
(a) Fig. 5.1 is a photomicrograph of part of the cortex of a kidney.
(a) State the general theory of evolution. (b) Different types of organism have evolved different structures containing light receptors. Eyes are o...
Define the term ecosystem.
(a) Oxidative phosphorylation takes place in the mitochondrion. Table 8.1 shows the different stages of oxidative phosphorylation. The stages are n...
(a) Fig. 1.1 shows a cholinergic synapse. presynaptic knob [Figure 1.1]
Albinism is a condition that results from disruption of a biosynthetic pathway involving the enzyme tyrosinase. It is estimated that 1 in 17000 peo...
The cilia of ciliated epithelial cells show variation in length, within an individual and between different individuals. Samples of ciliated epithe...
Rice, Oryza sativa, is an important food crop for human consumption. Two varieties of rice are T2A-1 and Shanyou 2. Shanyou 2 has been developed in...
(a) Fig. 5.1 is a photograph of a section through a kidney. [Figure 5.1]
(a) Regressive evolution is a change in a population over time that involves the loss of certain phenotypic characteristics. It is thought to be ca...
The passage below outlines one method used by a student to estimate the population size of an animal species. Complete the passage by using the mos...
(a) Table 8.1 shows some of the stages of glycolysis and respiration in anaerobic conditions in yeast. The stages are not listed in the correct ord...
A group of six students carried out an experiment to determine their reaction times using a ruler. Fig. 1.1 shows the basic procedure used for the ...
Artificial insemination (AI) is one method used in assisted reproduction programmes for large mammals. For many years, horse breeders have collecte...
Some students wanted to determine the reaction time of a sample of people aged from 5–80 years. The students found three different methods of testi...
Sperm production in humans is controlled by the hormones FSH and LH. These hormones are released from the pituitary gland in males to maintain a co...
One method of testing a person's reaction time is to use an online, computer click timer test. Some students carried out a test using the method de...