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.
Which combination of features is characteristic of a phloem sieve tube element as it is loaded from a source?
The diagrams show transverse sections of parts of a plant with some transport tissues labelled from 1 to 6. [Figure shows transverse sections of a ...
Which properties of lignin are important for the function of xylem vessels in the stem of a tall plant, such as a tree? 1 It is inflexible so does ...
A heating sleeve was placed around the trunk of a small tree at a height of 1 m above the ground. This allowed a narrow region of the tree trunk to...
The photomicrograph shows a section through a structure found in mammals viewed using a light microscope. [Figure shows a cross-section of an arter...
Which row correctly identifies the locations in which a type of molecule or cell can be present? [Table with molecule/cell type and locations: bloo...
Which statements about the formation of haemoglobinic acid are correct? 1 It is linked to the action of carbonic anhydrase. 2 It prevents blood fro...
The graph shows the oxygen dissociation curves of haemoglobin for eight species of mammal. [Figure shows oxygen dissociation curves for 8 mammals, ...
The statements list some of the events in the cardiac cycle. They are not in the correct order. 1 The impulse travels through Purkyne tissue. 2 The...
Which statement about typical bronchioles is correct?
Tobacco smoke contains substances that affect the functioning of the human body. [Table with substances W, X, Y and effects 1, 2, 3] What shows the...
Which two diseases are transmitted by airborne droplets?
Which features do the causative agents of measles, malaria and tuberculosis (TB) have in common? [Table with features: cytoplasm, the ability to pr...
What explains why most viruses that cause diseases in humans are unaffected by antibiotics?
Why does the white blood cell count increase in people with leukaemia?
Where are antibodies found during an immune response? [Table with locations: on the surface of pathogens, on the surface of memory cells. Key: ✓ = ...
The graph shows the changes that occur in the concentration of antibodies in the blood of a baby before birth and during the first few months after...
Fig. 1.1 and Fig. 1.2 are photomicrographs of sections through the leaves of two different plants. Fig. 1.1 is a photomicrograph of a section thro...
In mammalian red blood cells, carbonic anhydrase has an important role in the transport of carbon dioxide. Carbonic anhydrase is an enzyme.
In 2015, the World Health Organization (WHO) published the Global Technical Strategy for Malaria 2016-2030. The aim of this global strategy, which ...
In a double circulatory system, blood passes through the heart twice in one complete circuit of the body. The complete circuit consists of the pulm...
Human prolactin (hPRL) is a globular protein. It is a single polypeptide composed of 199 amino acids. The protein is transported in the bloodstream...
Plant and animal cells carry out mitosis to form two genetically identical cells from one original cell.
Before you proceed, read carefully through the whole of Question 1 and Question 2. Plan the use of the two hours to make sure that you finish the w...
P1 is a slide of a stained transverse section through a plant stem. You are not expected to be familiar with this specimen.
The effect of light intensity on the rate of photosynthesis can be investigated using a cut shoot of a pond plant. The apparatus used in the invest...
The hormone glucagon is an example of a cell signalling molecule. Table 2.1 lists the main events that occur when the blood glucose concentration d...
During an immune response, only B-lymphocytes with receptors that are specific to the antigens present are activated. Activation occurs when an ant...
Mexican spadefoot toads, *Spea multiplicata*, live on land but return to ponds to breed. Eggs are laid in water and hatch into tadpoles, which feed...
[Figure 5.1] shows the area of land that was used to grow genetically modified (GM) crops in the USA, Brazil, India and China from 2004 to 2015.
MELAS syndrome is an inherited disease caused by a mutation in a gene located in mitochondrial DNA (mtDNA). All mtDNA is inherited from the mother....
Isolated mitochondria were used to investigate respiration. • Mitochondria were extracted from respiring mammalian cells and incubated in a buffer ...
Explain what is meant by the term biodiversity.
Section B Answer one question.
In an investigation to find the water potential of onion tissue, some students used epidermal tissue from the storage leaves of a red onion. The va...
Cancer of the blood, including leukaemia and lymphoma, can be caused by mutations of stem cells in the bone marrow. A long-term study into the eff...
Phloem sap is transported from sources to sinks in phloem sieve tubes. Each sieve tube is constructed from phloem sieve tube elements.
Phosphatidate phosphatase (PAP) enzymes have an important role in lipid metabolism. The reaction catalysed by PAP is shown in Fig. 2.1. phosphatida...
During one cardiac cycle: • blood enters the heart from the lungs and from the rest of the body • blood leaves the heart to be transported to the l...
When a section of lung tissue is viewed using a light microscope, it is possible to identify the trachea, the bronchus, the bronchioles and the alv...
Myasthenia gravis and HIV/AIDS both involve disorders of the immune system.
Fig. 6.1 is a transmission electron micrograph of a plant parenchyma cell. [Figure 6.1]
Yeast cells contain an enzyme, catalase, which catalyses the release of oxygen from the substrate hydrogen peroxide. You will investigate the effec...
Starch grains from different types of plant differ in size and shape. Some starch grains have rings on their surfaces. You will now observe and dra...
Fig. 1.1 represents part of the wall of a proximal convoluted tubule (pct) in a kidney nephron. not to scale blood capillary cells of pct B A lumen...
Severe combined immunodeficiency (SCID) is a group of life-threatening diseases. SCID is caused by mutations that prevent the normal function of th...
Flowers of the common morning-glory plant, Ipomoea purpurea, can have several different phenotypes. An example of these flowers is shown in Fig. 3....
The rainbow trout, Oncorhynchus mykiss, is a fish that is bred in commercial fish farms. Rainbow trout that have a blue-silver colour are sold at a...
To identify the function of a gene, scientists can insert (add) a copy of the gene into a plasmid to create recombinant DNA. The plasmid is then tr...
The sea otter, Enhydra lutris, is a marine mammal that lives on the coasts of the North Pacific ocean. Fig. 6.1 shows a sea otter. [Figure 6.1] Tab...