Cambridge Past Paper Questions
Browse 23,045questions from 25 years of O-Level & A-Level exams. Click any question to practice.
Yeast cells contain enzymes that hydrolyse sucrose into reducing sugars, as shown in Fig. 1.1. enzymes in yeast cells sucrose → reducing sugars F...
Some organisms carry out respiration in anaerobic conditions when oxygen is not available or when there is a low concentration of oxygen. In yeast ...
Yeasts are unicellular organisms from the kingdom Fungi. Saccharomyces cerevisiae is one species of yeast that can carry out either asexual reprodu...
Research suggests that selective breeding began about 10000 years ago. Selective breeding has been important in satisfying the global demand for food.
A marker gene can be used when a gene of interest is introduced into a plant by genetic engineering.
The fruit fly, Drosophila melanogaster, has autosomal genes for body colour and wing shape. Gene B/b is involved in the production of body colour:...
When blood glucose concentration decreases, glucagon is released by the pancreas into the blood and is transported to the cells.
Fruits in the diet can be a source of vitamins, such as vitamin C and vitamin A, which are important in maintaining good health. Vitamin A is a gro...
Trypsin is a protease enzyme. A student compared the activity of trypsin from two different species: the Atlantic salmon, Salmo salar, and the dome...
Rocky shore ecosystems are found in some coastal regions. These ecosystems are inhabited by many different species of algae and animals. Twice each...
Abscisic acid (ABA) is a plant hormone that influences the growth and development of plants. Salicylic acid (SA) is a plant hormone that interacts ...
A light microscope is used to observe two structures that are 200nm apart on the slide. What is the actual distance between the two structures when...
A cell is shown in the micrograph. Which statement explains how it is possible to identify the type of microscope used to produce the micrograph?
Which statement supports the fact that mature plant cells contain organelles that carry out the same role as lysosomes?
Which cell structures may contain cisternae?
The diagram shows some cell structures of one type of cell. Which labelled cell structures are present in typical eukaryotic cells and typical bact...
The diagram shows part of a collagen fibril made of collagen triple helices. The collagen triple helices are linked to each other by one type of bo...
The table shows some information about the polypeptides that make up haemoglobin. α-globin: total number of amino acid residues in polypeptide chai...
Which feature of glycogen distinguishes it from starch?
The diagram shows a biological molecule. Which molecules would be produced if this biological molecule was hydrolysed?
A mixture of glucose and starch solutions was placed in a length of dialysis (Visking) tubing and the tubing sealed. The tubing was then placed in ...
The initial rate of a reaction catalysed by an enzyme was measured at various substrate concentrations. Which graph shows the effect of a low conce...
Gout is a type of arthritis in which small uric acid crystals form inside and around the joints. It causes sudden attacks of severe pain and swelli...
Phospholipids are formed in a similar way to triglycerides. A sample contained six phospholipid molecules. • The molecular weight of a phosphate io...
Which statements about phospholipids in cell surface membranes are correct? 1 Fatty acid tails allow most ions to pass through the membrane. 2 Hydr...
In an experiment, pieces of onion epidermis are put into three different concentrations of sucrose solutions, P, Q and R. The pieces of onion are l...
The electron micrograph shows rod-shaped bacteria. The actual length of the bacterium is 2.0 µm and the diameter is 0.5 µm. Assume that the bacteri...
Chickens have 78 chromosomes in the nucleus of a body cell. How many DNA molecules are there in a chicken body cell at the start of prophase of mit...
The photomicrograph shows cells undergoing mitosis. Which statement describes what will happen next in cell X?
Which processes occur in bone marrow cells that are in a mitotic cell cycle? 1 Phosphate groups bind to ADP molecules to form ATP. 2 Bonds form bet...
A polypeptide molecule contains the amino acid sequence: glycine - leucine – lysine – valine. The table shows DNA triplets for these amino acids. g...
The diagram shows a section of a strand of DNA. Which type of bond is labelled X?
Which row correctly describes cytosine?
During the production of protein molecules, only one strand from the DNA double helix is used. Which name is given to the DNA strand that is used t...
The diagram shows a longitudinal section of a phloem sieve tube with a companion cell. Where are the mitochondria located for the release of energy...
The diagram shows a phloem sieve tube element and a companion cell that are involved in translocation of sucrose. Which process correctly describes...
Which types of molecules are cotransported into companion cells?
The diagram shows a section through the human heart. Which label is correct?
The graph shows how the volume of the left ventricle changes during one cardiac cycle. Which point on the graph represents the start of atrial syst...
Which row is correct for an artery?
Which row shows the features of the gas exchange surface that increase diffusion of carbon dioxide and oxygen?
The electron micrograph shows some of the airways in the gaseous exchange system of an insect and the respiring body cells that surround them. Whic...
Which row is correct for the wall of the trachea and the wall of the bronchus?
A bacterial pathogen produces a protein that acts as a toxin. This toxin is harmful to humans. Scientists are developing monoclonal antibodies that...
Which statements are correct for penicillin? 1 It is harmful to prokaryotic cells. 2 It disrupts cell wall synthesis. 3 It becomes less effective w...
Which row is correct for the control or prevention methods for each disease?