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 cell structures can have mRNA inside them? 1 chloroplast 2 mitochondrion 3 nucleus 4 rough endoplasmic reticulum
Which structures are found in palisade mesophyll cells and photosynthetic prokaryotes? 1 cell surface membrane 2 cellulose wall 3 ribosomes 4 chlor...
Which polymers are present in all viruses and all prokaryotes? 1 polynucleotides 2 polypeptides 3 polysaccharides
Which set of steps is the best method for conducting the emulsion test for lipids?
A student was provided with a solution of carbohydrate. They removed two samples from the solution and performed tests on each sample, as shown. [F...
Which molecules contain at least two double bonds? [Figure 9.1]
What describes cellulose?
Which part of the structure of haemoglobin carries oxygen?
What is the maximum number of hydrogen bonds that can form between two single water molecules?
CYP3A4 is an important enzyme in the human digestive system where it is needed to break down a range of different toxins. The activity of CYP3A4 ha...
Which molecules in cell surface membranes are typically involved in cell recognition?
What can increase the fluidity of the cell surface membrane? 1 single bonds between carbon atoms in the fatty acid chains 2 cholesterol 3 longer-ch...
The three main factors that affect the rate of diffusion across a membrane can be expressed by the relationship shown. rate of diffusion is proport...
A student measured the time taken for complete diffusion of a dye into agar blocks of different sizes which were suspended in the dye. The results ...
An experiment was carried out to investigate the effect of concentration of sucrose solution on cells in a plant tissue. A sample of plant tissue w...
The diagram shows part of the organisation of a section of a DNA molecule and the associated histones, P and R, in prophase of mitosis. [Figure 20....
How many copies of each DNA molecule will be found in a cell at the start of the stages of the mitotic cell cycle shown?
One characteristic of DNA is that it is a universal genetic code. What is meant by a universal genetic code?
Which statement about mRNA is correct?
The diagram shows part of the process of translation. [Figure 24.1] What are the names of the structures labelled X, Y and Z?
The DNA triplets of genes are translated as amino acids or stop signals during protein synthesis. The table shows some of these triplets. [Figure 2...
Which row identifies cells with plasmodesmata?
Which statements about the apoplast and symplast pathways are correct? 1 In the apoplast pathway, water molecules move through free spaces in the c...
The diagram shows the outline of three xerophytic leaves of the same type in three different conditions, P, R and S. [Figure 29.1] Which descriptio...
The photomicrograph shows a transverse section of the leaf of a species of grass. [Figure 30.1] The grass is specially adapted to grow in a dry hab...
Which statement supports the theory of active loading of sucrose into companion cells?
Which properties of water are essential for its role in the transport of blood in mammals?
The diagram shows some of the events that happen between the plasma and the red blood cells in the circulatory system. [Figure 33.1] What do the nu...
The diagrams show the valves in the heart when viewed in cross-section from above at different stages in the cardiac cycle. [Figure 34.1] (diagram ...
Where are squamous epithelial cells found in the human gas exchange system?
Which statement about gas exchange between air in the alveoli and blood in the pulmonary capillaries is correct?
The average thicknesses for some structures in the human respiratory system are shown. [Figure 37.1] A molecule of oxygen is in the alveolar air sp...
The statements refer to the disease tuberculosis (TB). 1 The pathogen is not accessible to the immune system. 2 The bacterial pathogen reproduces s...
The average sizes of some pathogens are shown. [Figure 39.1] One type of air filter has been shown to be effective at preventing any pathogens of 1...
A successful vaccination programme provides a level of immunity where the majority of a population is protected. There are several factors that can...
Fig. 1.1 is a transmission electron micrograph of a cell from the stem of sago pondweed, Stuckenia pectinata.
Glycogen and cellulose are polymers. Fig. 2.1 shows small, representative regions of a glycogen molecule and a cellulose molecule.
Fig. 3.1 shows some fruits (grapes) of the grapevine, Vitis vinifera. Sucrose is transported in the phloem of the grapevine to the fruits. In the f...
The gene for the enzyme catalase is on chromosome 11 in humans.
Fig. 5.1 is a longitudinal section of a capillary in muscle tissue as viewed with a transmission electron microscope.
Fig. 6.1 is a diagram showing the passage of water through the tissues of a flowering plant from the soil to the atmosphere. The arrows show the di...
The sinoatrial node (SAN) and the atrioventricular node (AVN) have an important role in the control of the cardiac cycle. The timing of atrial and ...
Fig. 2.1 is a photomicrograph of a longitudinal section (LS) through a root tip. Two different regions are visible: • the root apical meristem • th...
Cells of the immune system respond to the presence of non-self antigens.
Trypanosoma brucei is a unicellular organism that causes the infectious disease known as sleeping sickness. Insects known as tsetse flies pass on t...
Nucleotide and nucleoside analogues are therapeutic drugs that have a similar structure to nucleotides or nucleosides of RNA and DNA. A nucleoside...
The Weibel Lung model was developed after an extensive study of the gas exchange system. The model includes detailed measurements of airway diamete...
The cells in a tissue are often at different stages of the cell cycle.
The number of cases of tuberculosis (TB) is affected by many biological, social and economic factors.
Blood contains white blood cells and red blood cells.