Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Which structures will be present in a cell that causes cholera? 1 circular DNA 2 cytoplasmic DNA 3 70S ribosomes
Which organelles have a partially permeable membrane? 1 Golgi apparatus 2 lysosome 3 mitochondrion 4 ribosome
Mouse cells were grown in a dish containing a growth medium. Radioactively labelled amino acids were added to the growth medium. The table shows th...
The electron micrograph shows a section through a cell. [Electron micrograph of a cell] What would be present in this type of cell?
A student carried out four tests for biological molecules. The observations are shown in the table. [Table with columns 'test' and 'observations' a...
The diagram shows some relationships between features of carbohydrates. [Venn diagram showing α-glucose, 1,4 bonds, highly branched and regions 1, ...
The diagram shows a triglyceride molecule. [Diagram of a triglyceride molecule] Which statement is correct for the structure and function of this t...
Enzyme P has been found in a tropical grass. • The enzyme catalyses the hydrolysis of the fungal polysaccharide, chitin, into amino sugars. • It al...
Which bonds between amino acids hold the shape of the secondary structure and also the tertiary structure of proteins?
Resilin is a protein found in the wings of insects. It is an elastic, fibrous protein and scientists have suggested that it may have an important r...
Collagen is a protein that helps to strengthen and increase the elasticity and hydration of the skin. Aging can lead to dry skin and the formation ...
What is the effect of an enzyme in an enzyme-catalysed reaction?
How is the Michaelis–Menten constant (Kₘ) used?
Some students investigated the effect of pH on the rate of starch digestion by amylase at 20 °C. • They added 2 cm³ of a 1% amylase solution and 1 ...
Which statements are correct for a non-competitive inhibitor of enzyme action? 1 Increasing the concentration of the enzyme's substrate will reduce...
What can increase the fluidity of the cell surface membrane at low temperatures? 1 double bonds between carbon atoms in the fatty acid chains 2 cho...
Which statements about the proteins and glycoproteins in cell surface membranes are correct? 1 They can allow cells to bond together to form tissue...
In an experiment, four different-sized cubes of colourless agar were placed into a blue dye. The time taken for each cube to turn blue was recorded...
The stalk of a dandelion flower is a hollow tube called a scape. Pieces of the scape are cut as shown by the dotted lines and placed in sucrose sol...
Telomeres prevent the loss of genes during DNA replication. Which row correctly shows cell types that contain telomeres?
Which events listed are part of mitosis? 1 interphase 2 prophase 3 cytokinesis
The photomicrograph shows 17 cells in different stages of the mitotic cell cycle. [Photomicrograph of cells in different mitotic stages, with cell ...
The flow diagram shows some of the stages in the replication of a lagging strand of DNA. [Flow diagram: 'The DNA double helix begins to unwind.' ->...
In a gene, the 20 common amino acids are each coded for by three bases in adjacent nucleotides. Why is there a difference between the number of ami...
How is a primary transcript modified to form mRNA?
The diagram shows protein synthesis in a prokaryote. [Diagram of protein synthesis in a prokaryote showing DNA, cell wall, X, Y, tRNA 1, tRNA 2, mR...
The photomicrographs show sections of two organs of a plant. [Two photomicrographs (A and B) of plant organ sections] Which letter identifies a cel...
Which row correctly describes the pressure in the xylem and the water potential in the root hair cells used in the transport of water in a transpir...
Which row correctly identifies the definitions for each of the key terms used in transpiration?
Which combination of features is characteristic of a phloem sieve tube element immediately after it is loaded from a source?
Which blood vessel carries blood with the lowest pressure?
The photomicrograph shows cells found in mammalian blood. [Photomicrograph of mammalian blood cells, with one cell labelled P] What is cell P?
The diagram shows the Bohr shift in actively respiring cells. [Graph showing percentage saturation of haemoglobin with oxygen against partial press...
The bar chart shows the mean thickness of the walls of the main chambers in a mammalian heart. [Bar chart showing mean wall thickness /mm for heart...
The diagram shows parts of the gas exchange system in humans and the associated cells or structures. [Boxes with labels: alveolus, bronchiole, bron...
The photomicrograph shows the wall of a bronchus as seen with a light microscope. [Photomicrograph of the wall of a bronchus with labels X, Y, Z] W...
Which factors affect the global pattern of distribution of malaria? 1 the disease is mainly restricted to tropical and subtropical environments 2 t...
Which molecule could be a self antigen?
The diagram shows an antibody molecule with some parts labelled. [Diagram of an antibody molecule with parts P, W, V, U, R, S, T labelled] Which ro...
Fig. 1.1 shows a diagram of the fluid mosaic model of the structure of the cell surface membrane.
Fig. 4.1 is a photomicrograph of a copepod. These animals are found living in sea water and in fresh water environments.
Fig. 5.1 is a photomicrograph of a longitudinal section through part of the stem of a plant.
Alveolar macrophages are phagocytes found in the human gas exchange system. They produce hydrolytic enzymes, such as lysozyme, to digest pathogens ...
The wall of the small intestine is highly folded to form villi. Between the villi are infoldings known as crypts of Lieberkühn. Fig. 1.1 is a diagr...
Cholera is an infectious intestinal disease caused by a bacterial pathogen.
The gene LCT codes for the enzyme lactase. In babies, lactase synthesis is necessary for digesting lactose, the sugar found in milk. Another gene, ...
Bacteria can be classified according to the type of cell wall they have. Gram-negative bacteria have a cell wall with an outer layer known as the o...
A plant that is described as a mesophyte has evolved to grow in conditions that do not normally experience water stress (low availability of water)...