Cambridge & Pearson Edexcel Past Paper Questions

What is the order of size of cell structures?

A sample of a solution of sucrose tested for reducing sugars remains blue, but when another sample of the same solution is tested for non-reducing ...

Which molecules contain at least two double bonds? [Figure 8.1 (Venn diagram showing circles for collagen, saturated triglyceride, haemoglobin, wit...

Amylose, amylopectin and glycogen are all polysaccharides. Enzyme X removes one maltose molecule at a time from the ends of a polysaccharide molecu...

Which property of water enables sweating to be an efficient means of losing heat from the body?

Which bonds are found in the levels of structure of a protein molecule?

Prokaryotes and eukaryotes use extracellular enzymes. Extracellular digestive enzymes are found in the external environments of some prokaryotes. S...

Amylase breaks down starch molecules. Which substance will have the same number of molecules for the duration of this reaction?

Which graphs could show the effect of pH on the rate of enzyme-catalysed reactions? [Figure 14.1 (four graphs of rate of reaction vs pH)]

After a heart attack, the enzyme lactate dehydrogenase leaks into the blood plasma from damaged heart muscle. What is required to measure the activ...

Which graph correctly shows Km and Vmax? [Figure 16.1 (four graphs showing rate of reaction vs concentration, with Vmax and Km indicated)]

Cell membranes become less fluid as the temperature decreases. Bacteria and yeast cannot regulate their cell temperatures. How do bacteria and yeas...

Samples X, Y and Z are epidermal tissues cut from an onion. Each epidermal tissue was immersed in one of three different concentrations of a salt s...

The graph shows the results of an osmosis investigation using potato tissue. [Figure 19.1 (graph of percentage change in mass vs concentration of s...

Some agar was coloured pink using a pH indicator. The pink agar was then used to make three agar cubes with different dimensions. [Figure 20.1 (thr...

The diagram shows the arrangement of chromosomes with attached spindle fibres during a stage of mitosis. [Figure 21.1 (diagram of chromosomes with ...

During which phase of the cell cycle does DNA replication take place?

Human body cells in interphase have 46 chromosomes. What is correct about the number of telomeres present in prophase of a human body cell?

Sometimes hydrogen bonds form temporarily between the bases of two strands of RNA. How many hydrogen bonds form when guanine and uracil each bind t...

The table shows all the possible DNA triplet codes for some amino acids. amino acid: cysteine, DNA triplet code: ACA amino acid: cysteine, DNA trip...

Which row is correct for transpiration?

Which features of companion cells and xylem vessel elements make them suitable for their function?

The diagram shows some root cells. [Figure 28.1 (diagram of root cells with water pathway indicated)] Which statement is correct for the pathway sh...

The graph shows the diameter of a tree trunk at different times. [Figure 29.1 (graph of diameter of tree trunk vs time of day, with points J, K, L)...

The plan diagrams of transverse sections of two plant organs are shown. These are not drawn to scale. [Figure 30.1 (plan diagrams of plant organs w...

The diagrams show three types of blood cells, which are all drawn to the same scale. [Figure 31.1 (diagrams of three blood cells X, Y, Z, with nucl...

The graph shows oxygen dissociation curves for three animals. The shape of each curve is influenced by respiration rate and the affinity of haemogl...

Which statements about a mammalian heart are correct? 1 The right atrium and right ventricle contain deoxygenated blood going to the lungs. 2 The l...

How is most carbon dioxide transported in the blood?

Which row shows the tissues that are present in the wall of the trachea and the wall of the bronchus?

Which factors maintain the diffusion gradient for carbon dioxide at the surface of the alveoli? 1 blood flow around the alveoli 2 breathing movemen...

A student made notes about two diseases: hand, foot and mouth disease (HFMD) and Lyme disease. HFMD is caused by a viral pathogen and is transmitte...

Which statements explain why antibiotics may not treat cholera successfully? 1 The infectious organism has developed resistance to the antibiotic. ...

The statements describe the phagocytosis of a bacterium by a macrophage. 1 Digestive enzymes break down the bacterium. 2 Lysosome fuses with the va...

Amylose and the triglyceride stearin are macromolecules. Students used the enzyme maltase extracted from the fungus Aspergillus oryzae to investiga...

In mammals, the small intestine is the main site of absorption of the products of digestion. Fig. 2.1 is a transmission electron micrograph of a lo...

Scientists investigated the progress of reactions catalysed by two enzymes: dopa oxidase and neutrase. The reactions catalysed by these enzymes res...

Cells of the immune system have cell surface receptors that detect molecules made by pathogens. One of these cell surface receptors is known as TLR...

Phosphate ions are absorbed from the soil solution by roots and are needed for cellular processes throughout plants. Scientists investigated the mo...

Fig. 6.1 is a ribbon model of a molecule of haemoglobin. The effect of the partial pressure of oxygen (pO2) and the effect of the partial pressure ...

Root hair cells are specialised plant cells located in the outer layer of young roots of plants. Root hair cells have an essential role in the upta...

The transport of respiratory gases involves blood plasma and red blood cells. Red blood cells contain the globular protein, haemoglobin.

Carrots are root vegetables of the carrot plant. The carrot plant is an important food crop that is grown throughout the world. Carrots have a swee...

Tuberculosis (TB) is an infectious disease that is caused by a bacterial pathogen. The pathogen has mechanisms to avoid digestion by phagocytes. Ma...

There is a global shortage of blood for transfusions. Researchers can culture bone marrow stem cells in the laboratory to manufacture red blood cel...

Horseradish peroxidase (HRP) is an enzyme that can be extracted from the roots of the horseradish plant, Armoracia rusticana. HRP is used extensive...

Ranunculus is a group (genus) of dicotyledonous plants that includes more than 1600 species. (a) Fig. 1.1 is a photomicrograph of a transverse sect...

Bees are insects that produce venom as a means of self-defence. Melittin is a polypeptide present in the venom of bees.

Staphylococcus epidermidis is a species of bacterium that lives on human skin. Staphylococcus aureus is a pathogenic bacterium that can infect humans.

Lysosomes are membrane-bound organelles found in mammalian cells.