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 rows show the chemical groups present in the biological molecules listed?
The diagram shows the formation of a biological macromolecule. [Figure 10.1]
Fibrous proteins are composed of chains of amino acids held together by bonds. An example of part of a fibrous protein is shown. [Figure 11.1]
Which row about the structure of proteins is correct?
A student wrote four statements about water. 1 Water has a high specific heat capacity which maintains the temperature of water within cells. 2 Mam...
Which statement about the active site of an enzyme is correct?
An experiment was carried out to compare the effect of pH on the activity of an enzyme that was in solution and the same enzyme that had been immob...
High concentrations of ethanol can disrupt cell membrane structure and make the cell surface membrane leaky. Yeast cells release ethanol as a waste...
The photomicrograph shows the appearance of onion epidermal cells after they have been soaked in solution X for one hour. [Figure 18.1]
Equal sized potato pieces were placed into a test-tube and covered with a sucrose solution. The test tube was left for 30 minutes. All other variab...
Which row shows the correct number of each component of a single chromosome during prophase of mitosis?
The RNA triplet UAG acts as a stop codon terminating the synthesis of a polypeptide. The diagram shows a strand of DNA which codes for four amino a...
What is correct for uracil?
The photomicrograph shows a vascular bundle. [Figure 24.1]
Which features have a role in the transport of water in xylem vessel elements? 1 capillary action 2 cohesion 3 hydrogen bonding
What is a definition of transpiration?
Which are present in the walls of arteries?
The statements list some of the events in the cardiac cycle. They are not in the correct order. Which statement describes the fifth of these events...
Which row correctly identifies the molecules or cells that are present in the different locations?
When active tissues have high carbon dioxide concentrations, oxyhaemoglobin releases oxygen to these tissues. What encourages this release in the p...
The graph shows oxygen dissociation curves of haemoglobin at two different carbon dioxide concentrations. The partial pressure of oxygen in the lun...
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 (...
Some symptoms of chronic obstructive pulmonary disease (COPD) are listed. 1 bursting of alveoli 2 loss of elastic fibres 3 increase in secretion of...
The diagram shows properties of diseases. Which shows the properties that are common to tuberculosis (TB) and measles? [Figure 35.1]
The diagram shows some of the pathogens that cause disease in humans and some of the ways they are transmitted. [Figure 36.1] What is the correct p...
Different antibiotics function in different ways. It is important that the antibiotic kills the bacteria, but does not harm the infected human. The...
Immune response to a vaccination against a virus can be assessed by making three measurements: 1 the concentration of anti-virus antibody in the bl...
The enzyme telomerase prevents loss of telomeres after many mitotic cell cycles. Which types of white blood cell involved in an autoimmune conditio...
Which features of monoclonal antibodies make them useful in the diagnosis and treatment of disease? 1 A particular monoclonal antibody attaches to ...
Fig. 1.1 shows the structure of the amino acid glycine. [Figure 1.1]
Fig. 2.1 is a transmission electron micrograph showing the bacterial pathogen that causes tuberculosis (TB). [Figure 2.1]
A student carried out an experiment to investigate the effect of increasing the concentration of sucrose solution on the mass of potato tissue. • P...
(a) Fig. 4.1 is a photomicrograph of a human blood smear. [Figure 4.1]
Myasthenia gravis is a condition that results in muscle weakness by affecting the immune response.
Outline the role of DNA polymerase in the replication of DNA.
Fig. 1.1 is a photomicrograph of a transverse section through the stem of creeping buttercup, Ranunculus repens. [Figure 1.1]
People who smoke tobacco are at an increased risk of developing non-infectious diseases of the gas exchange system and the cardiovascular system. I...
A red blood cell goes through a number of stages in the bone marrow before it is released into the circulation to carry out its role of oxygen tran...
Carbohydrates, proteins and nucleic acids are types of biological molecule. Within each type, there are examples of molecules that can be described...
Countries that have a high number of cases of malaria also have problems with diseases caused by bacteria. This means that many people in these cou...
Telomerase is an enzyme that is important in maintaining the telomeres that are located at the ends of chromosomes.
Fig. 1.1 is a diagram of a molecule of haemoglobin.
Meristematic tissue is found in the growing region of plants, such as root tips. Fig. 2.1 shows a section through the meristematic region of a root...
The tomato plant, Solanum lycopersicum, does not tolerate periods of drought (water shortage). Researchers have produced a tomato plant that has an...
In mammals, arteries branch to form smaller blood vessels called arterioles. Arterioles branch to form capillaries that supply blood to tissues. Fi...
Influenza is an infectious disease caused by the influenza A virus. This virus causes influenza in birds and mammals. Fig. 5.1 is a diagram of an i...
Fig. 6.1 is a diagram of the cell surface membrane of a squamous epithelial cell lining an alveolus.
J1 is a slide of a stained transverse section of a plant stem. You are not expected to be familiar with this specimen. Use a sharp pencil for drawi...
ADH is a hormone that is released into the blood of a mammal when changes occur in the internal environment.
The stickleback fish, *Gasterosteus aculeatus*, has two distinct forms, the saltwater form and the freshwater form. The larger, freshwater form is ...