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.
When they remain at high altitudes the red blood cell count of humans increases. Why does this occur? 1 to increase the Bohr effect 2 to increase t...
Which comparisons of blood, tissue fluid and lymph are correct? 1 Blood has a higher concentration of proteins than tissue fluid because the larger...
The photomicrograph shows a section through lung tissue. [Photomicrograph of lung tissue] Which structures are present in this photomicrograph? [Ta...
An athlete who smokes just before a race may not be able to run at their maximum speed because less oxygen is carried by the blood. Which explanati...
Some of the requirements of an efficient gas exchange system are a large surface area and a short diffusion distance. What is correct about how alv...
The diagram shows three types of cell found in the human gas exchange system. [Diagrams of three cell types labeled X, Y, Z] Apart from causing can...
Some common antibiotics are listed. The action of each antibiotic is described. 1 rifampicin – inhibits RNA polymerase 2 streptomycin – inhibits 70...
What could cause an outbreak of malaria in a country after it had been eliminated? 1 mosquitoes become resistant to insecticides 2 migration of pop...
Which disease is caused by a bacterium and can be spread by airborne droplets?
Smallpox has been eradicated, but malaria and cholera have not. Which statements correctly explain this? 1 Cholera pathogens in the intestines are ...
When a person is given a vaccination immunity to certain pathogens develops. Which of the effects of vaccination are correct? 1 production of antib...
What is the first response by the immune system to a pathogen?
Answer all the questions. (a) Each of the statements A to D describes a structure found in eukaryotic cells. Identify the structure that is describ...
Phosphatases are enzymes that catalyse the removal of phosphate groups from organic compounds. Some students investigated the effect of substrate c...
Fig. 3.1 is a diagram that shows the structure of an antibody molecule. [Figure 3.1]
(a) Fig. 4.1 shows part of a DNA molecule. [Figure 4.1] Use Fig. 4.1 to explain how the structure of mRNA differs from the structure of DNA. (b) Fi...
Sugar molecules enter cells through transport proteins. (a) Explain why transport proteins are required for the movement of sugar molecules, such a...
Cholera bacteria release the toxin, choleragen, when they are in the intestine. (a) (i) Name the bacterium that is the pathogen of cholera. (ii) De...
In multicellular organisms, the structure of different cell types is adapted to their function. Within these cells there are a number of different ...
Lipase is an enzyme with many commercial uses. Some species of bacteria are of great interest as they produce large quantities of lipase.
Malaria is a disease caused by the protoctist, Plasmodium. The organism has a very complex life cycle as it has two hosts, a human and a mosquito. ...
Meristematic tissue is found in the growing regions of plants, such as root tips.
Some pathogens can enter the human body through the gas exchange system.
As a result of transcription and translation, a polypeptide chain is produced. Proteins with quaternary structure contain two or more polypeptide c...
Mammals have a closed double circulation system.
Fig. 2.1 is a transmission electron micrograph of a cell from a leaf. [Figure 2.1]
Name the causative organism of tuberculosis (TB).
Complete Table 4.1 by using a tick (✔) to indicate which statements apply to each of the molecules. Use a cross (x) for statements that do not appl...
Describe the process of DNA replication.
In the space below, draw a diagram to show a hydrogen bond between two water molecules.
J1 is a slide of a stained transverse section through a plant stem. You are not expected to be familiar with this specimen.
M1 is a slide of a stained transverse section through a plant stem. You are not expected to be familiar with this specimen.
When a person eats food containing starch, the enzyme amylase is released to hydrolyse (break down) the starch into reducing sugar. As the food pas...
K1 is a slide of a stained transverse section through a plant root. You are not expected to be familiar with this specimen. You are required to: • ...
The mammalian kidney is an organ involved in homeostasis.
Corals grow in shallow seawater. Corals consist of colonies of small animals called polyps. These polyps have photosynthetic protoctists called alg...
Oil seed rape (canola), Brassica napus, has been genetically modified to be resistant to herbicides containing glufosinate ammonium. The geneticall...
ATP is used or produced at different stages in the respiration of glucose in aerobic conditions. Complete the table to show whether ATP is used or ...
The red poppy, Papaver rhoeas, and several species of daisy of the family Compositae often co-exist as weeds of wheat fields. Fig. 5.1 shows change...
(a) Describe how tropomyosin and myosin are each involved in the sliding filament model of muscle contraction.
The stems of raspberry plants have spines. [Figure 7.1] The colour of the spines is controlled by two genes, A/a and B/b. The two genes are on diff...
There is considerable variation in the ecosystems that occur in the continent of North America. These include coniferous forest, prairie grassland,...
Explain how dip sticks function to test for glucose in a sample of urine.
Describe the structure of a motor neurone.
(a) Fig. 1.1 represents the link reaction. R + coenzyme A NAD reduced NAD S + acetyl coenzyme A Fig. 1.1 With reference to Fig. 1.1:
Chloroplasts belong to a group of organelles called plastids. Although different types of plastid have different structures and functions, one type...
Fig. 3.1 shows a diagram of two sarcomeres of relaxed striated muscle. [Figure 3.1]
Weeds reduce crop yields by competing with crop plants for space, light, water and minerals. The modes of action of three different types of herbic...
Cancer is a disease in which normal controls over cell division are lost and malignant tumours form. An early diagnosis of many types of cancer can...
(a) Fig. 6.1 is a diagram of a Bowman’s (renal) capsule of a nephron from a mammalian kidney. [Figure 6.1]