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.
Inheritance of petal colour and pollen shape in sweet pea plants are controlled by two genes. • Gene P/p controls petal colour. Allele P for purpl...
When bananas ripen, they turn brown in colour. This is due to the formation of a brown product called melanin. The enzyme catechol oxidase acts on ...
Inheritance of wing shape and eye colour in the fruit fly, Drosophila melanogaster, is controlled by two genes. • Gene N/n controls wing shape. All...
The photomicrograph shows a bronchiole and alveoli. The magnification of the image is ×360. What is the maximum diameter of the bronchiole lumen?
A specimen is observed twice with a microscope, firstly using green light with a wavelength of 510 nm and then using red light with a wavelength of...
What is found in chloroplasts and mitochondria?
Which feature is correct for all known viruses?
Four extracts from different plant materials were made and tested with Benedict's solution. The extracts were boiled with Benedict's solution for ...
Which have properties that are dependent on hydrogen bonds? 1 cellulose 2 a molecule of haemoglobin 3 water
Which statement is correct?
The diagram shows two amino acids. Some of the hydrogen atoms are numbered 1 to 6. [Figure showing two amino acid structures with H atoms numbered ...
A student wrote four statements about water. 1 Water has a high specific heat capacity which maintains the temperature of water within cells. 2 Ma...
Typical enzymes are large globular proteins with a specific tertiary shape. Which molecular interactions are directly involved in maintaining the ...
Which statement about the Michaelis–Menten constant (Km) is correct for an enzyme with a low affinity for its substrate?
Long chain, saturated fatty acids change from solid to liquid at higher temperatures compared with short chain, unsaturated fatty acids. Which fat...
When animal cells are cultured, salt solution is added to keep the cells alive. What is the purpose of the salt solution?
The following are all processes that allow movement into cells. 1 phagocytosis 2 active transport 3 facilitated diffusion Which processes require...
Which features are required to allow for efficient diffusion? 1 a large surface area 2 a short diffusion pathway 3 maintenance of a constant diffu...
What is a role of mitosis?
Telomeres prevent the loss of genes from the ends of chromosomes during DNA replication, but they become shorter each time they are copied. In can...
The nucleus of a mouse body cell in G₁ phase of the cell cycle has 1.2 × 10⁻¹² g of DNA. What will be the mass of DNA in the nucleus of the cell a...
What occurs during prophase in animal cells? 1 fragmentation of the nuclear envelope 2 nucleolus disappears 3 stained chromosomes become visible 4...
Which statement describes the structure of ATP?
Rifampicin is an antibiotic used to treat tuberculosis. It works by inhibiting RNA polymerase in bacteria. Which processes are directly inhibited...
The table shows the DNA triplet codes for some amino acids. amino acid DNA triplet code amino acid DNA triplet code arginine GCA glycine CCA argin...
Some of the features present in transport tissues are listed. 1 lignified walls 2 cytoplasm 3 mitochondria 4 pits 5 plasmodesmata Which features ...
The diagrams show transverse sections through parts of plants. [Figure showing three transverse sections of plant parts labeled 1-6] Which row is ...
Which molecules form hydrogen bonds with water during transpiration? 1 cellulose in the xylem wall 2 suberin in the xylem wall 3 other water molec...
Some plant species can take up heavy metal contaminants that are dissolved in soil water and then transport them within the plant. Within plant cel...
What is the correct route for the movement of water from cell to cell in the apoplast pathway?
Which row shows the correct sequence for the movement of sucrose into phloem sieve tubes?
What occurs during ventricular systole in a mammalian heart? 1 Aortic pressure increases. 2 Atrial pressure does not change. 3 Ventricular pressur...
Which plan diagram represents the tissues in a major vein?
The diagram shows the pressure changes in various structures of the left side of the heart during the cardiac cycle. [Figure showing a graph of pre...
Which description of movement of substances during tissue fluid formation is correct?
Which row shows the change in concentration of some substances in red blood cells when carbon dioxide diffuses from active cells?
Which statements about the human gas exchange system are correct? 1 The absence of cartilage in small bronchioles allows them to expand. 2 The wal...
Four types of cell in the gas exchange system are listed. J alveolus epithelium cell K ciliated cell L goblet cell M smooth muscle cell The ticks...
Why is it difficult to control the spread of tuberculosis? 1 Global air travel for commerce and tourism has increased. 2 The bacterium that causes...
Rabies is a viral disease which can be spread to humans by a bite from an infected animal. One method of treatment is to inject the patient with a...
A student used a diagram to show four types of cells involved in the primary immune response. [Figure showing a diagram with cells types 1, 2, 3, 4...
Fig. 1.1 and Fig. 1.2 are photomicrographs showing the distribution of tissues in the lungs. Fig. 1.1 is a photomicrograph of a section through par...
B-lymphocytes are activated to form plasma cells during immune responses. Fig. 2.1 is a drawing of a plasma cell made from a transmission electron ...
A tyrosine kinase receptor (TKR) is a protein complex found in the cell surface membrane of mammalian cells. TKR has two components involved in the...
Adipocytes are cells found in adipose tissue in mammals. These cells absorb glycerol and fatty acids to make triglycerides for long-term storage. F...
Infectious diseases are caused by pathogens and are described as transmissible diseases.
Cotransporter proteins are membrane proteins found in companion cells of phloem tissue. Messenger RNA (mRNA) is the molecule in cells that carries ...
Epithelial cells in the small intestine have cell structures known as microvilli. The microvilli of these cells are found only on the surface that ...
Cholera is a life-threatening and infectious disease caused by the bacterium Vibrio cholerae. One of the symptoms of the disease is severe diarrhoe...
Hummingbirds are the smallest of birds and are found in the Americas. Some species migrate hundreds of kilometres between warmer overwintering area...