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.
Stained onion cells undergoing mitosis were observed using a microscope. Which row is correct for mitosis in plant cells?
How many statements about semi-conservative replication of DNA in a eukaryotic cell are correct? 1 The process takes place in the cytoplasm. 2 An a...
A section of the polypeptide coding for the haemoglobin β-chain contains the following amino acids. – Pro – Glu – Glu – Patients with sickle cell a...
Which diagram correctly represents temporary hydrogen bonding during transcription?
The electron micrograph shows a longitudinal section through part of a plant stem. [Electron micrograph] What is X?
Sodium chloride is added to a culture solution containing freshwater single-celled plant cells. What happens to the water potential of the culture ...
Which statements correctly describe transport pathways in dicotyledonous plants? 1 In the apoplast pathway, water may move through plasmodesmata. 2...
Which statement about the movement of water from roots to leaves is not correct?
Which terms describe the method by which water is transported within xylem vessel elements? 1 cotransport 2 cohesion-tension 3 osmosis
The photomicrograph shows a blood smear. [Photomicrograph] Which cell is a monocyte?
The table shows some information about three blood vessels, P, Q and R, from a mammal. Which row identifies blood vessels P, Q and R?
Ventricular septal defect (VSD) is a heart defect that people can have from birth. People with VSD have a hole in the wall (septum) that separates ...
Which statement about the structure of the heart is correct?
What can be found in the wall of an alveolus in the lungs of a human?
What are the functions of cilia in the gas exchange system? 1 to move mucus 2 to trap pathogens and dust 3 to increase the surface area
Cholera and tuberculosis are infectious diseases that can spread when people have to live in overcrowded conditions. Which strategies would help co...
Immunity to certain pathogens develops when a person is given a vaccination. Which effects of vaccination are correct? 1 production of antibodies t...
A student wrote three statements about antibodies. 1 Their structure depends on peptide, hydrogen and disulfide bonds. 2 They are protein molecules...
Fig. 1.1 is a transmission electron micrograph showing a section of a human liver cell. [Figure 1.1]
Fig. 2.1 is a simplified diagram of the human circulatory system. [Figure 2.1]
Carbonic anhydrase is a globular protein found in red blood cells.
Scientists have produced structures known as virosomes, which are used in certain vaccines. Virosomes do not cause disease. Fig. 4.1 is a diagram o...
When water molecules enter a plant through the roots, the molecules cross the cortex and enter the xylem tissue to be transported to other parts of...
Fig. 6.1 is a photomicrograph of plant cells in stages of the mitotic cell cycle. [Figure 6.1]
The mammalian circulatory system is adapted for the long-distance transport of the respiratory gases, oxygen and carbon dioxide. The system is desc...
Human cytomegalovirus (HCMV) is a common virus affecting humans. In people with a fully functioning immune system, infection by HCMV usually causes...
Plasmodium falciparum is one species of Plasmodium that causes the life-threatening disease malaria. With early diagnosis and the correct drug trea...
The airways of the gas exchange system are lined with epithelium. Gradual changes in the structural features of this epithelium occur as the airway...
Fibroblasts are one of the cell types of connective tissue. The cells synthesise and secrete collagen, which forms part of the supporting external ...
Xylem and phloem are the transport tissues of plants. Both tissues have more than one cell type. The conducting cells of xylem contain xylem sap an...
During translation, a polypeptide is synthesised when amino acids are added to a growing chain of amino acids. Fig. 1.1 shows part of a growing cha...
Fig. 2.1 is a scanning electron micrograph showing a macrophage engulfing some bacteria. [Figure 2.1]
Students investigated the relationship between two environmental factors and the rate of cavitation in a Scots pine tree, Pinus sylvestris, over a ...
The early development of an animal involves divisions of the zygote and daughter cells by mitosis to form an embryo consisting of genetically ident...
Cathelicidin LL-37 is a cell signalling compound that stimulates many different cells in humans. One role of cathelicidin LL-37 is stimulating the ...
Fig. 6.1 shows some of the events that occur when a red blood cell flows through a capillary in the lungs. [Figure 6.1]
Some fruit contains large quantities of ascorbic acid (vitamin C). Ascorbic acid can be absorbed through the partially permeable wall of the gut. ...
You are provided with a solution labelled E containing an enzyme which coagulates (clots) milk. Enzyme E hydrolyses (breaks) peptide bonds between ...
The wild Bactrian camel, Camelus ferus, lives only in the desert regions of Mongolia and northern China. Fig. 1.1 shows a wild Bactrian camel. [Fig...
Photosynthesis is an important energy transfer process.
(a) The results of investigations carried out on mitochondria show how the structure of a mitochondrion is related to its role in aerobic respirati...
Adenosine deaminase (ADA) deficiency is an immune system disorder caused by a recessive autosomal mutation. Severe combined immunodeficiency caused...
A large number of alpine plant species grow in the mountains of New Zealand's South Island. Alpine plants are defined as plants that live above the...
Selective breeding has been used to improve the characteristics of crop plants, including maize and rice.
(a) In some varieties of domestic cats the gene for fur colour is located on the X chromosome. This gene has two alleles. One allele codes for blac...
Fig. 8.1 is a diagram of a kidney nephron. [Figure 8.1] With reference to Fig. 8.1, name A, B and C.
(a) A neuromuscular junction allows the transmission of an action potential from a motor neurone to a striated muscle fibre, causing it to contract...
The passage below outlines homeostasis. Complete the passage by using the most appropriate scientific terms. Homeostasis, in mammals, is the proces...
The Asiatic lion, Panthera leo persica, is found only in the Gir Forest National Park in the Gujarat region of western India. Fig. 1.1 shows a fema...
Yeast cells can respire in anaerobic conditions. Bioethanol is a type of biofuel produced from maize starch on an industrial scale. In the high tem...