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.
J1 is a slide of a stained transverse section through a plant leaf.
Some biological molecules produce a colour change when tested with a specific reagent. You will investigate which biological molecules are present ...
L1 is a slide of a stained transverse section through a plant leaf. (a) Set up the microscope so that you can observe the section on L1. Use a shar...
Photosynthesis is a complex process involving the transfer of light energy into chemical energy. The rate of photosynthesis is affected by many env...
All organisms respire to release energy from energy-rich molecules such as glucose. Some factory workers in the early 20th century were exposed to ...
In 2014, scientists published a phylogenetic (evolutionary) tree diagram showing how and when different groups of insects developed from ancestral ...
Genetic engineering involves the manipulation of naturally occurring enzymes and processes. Genetically modified organisms (GMOs) include crop plan...
Nerves consist of bundles of different types of neurones. Fig. 5.1 shows the mean transmission speed of impulses for three types of sensory neurone...
Thermoregulation is the control of the core temperature of the body. Thermoreceptors send information about a change in core temperature to the hyp...
People vary in which molecules are present on the surface of their red blood cells. For example, in the ABO blood group system, people may be categ...
Humans use selective breeding to improve the features of crop plants and domestic animals.
Describe how you would carry out an investigation to calculate the effect of substrate concentration on the rate of respiration of yeast in anaerob...
Explain how speciation can occur due to geographical separation.
(a) Fig. 1.1 is a diagram of part of a neurone membrane at resting potential. [Figure 1.1]
(a) All organisms respire. The ATP produced as a result of respiration is used as the energy currency of the cell. (b) Fur seals are mammals that ...
(a) One way to measure global biodiversity is to count the number of species of organisms. Table 3.1 shows estimates for 2009 of the number of spe...
(a) Genetic technology involving the creation of recombinant DNA can be used to treat different human diseases. These include diseases such as diab...
(a) Photosynthesis is a complex process involving a light dependent stage and a light independent stage. A student carried out an experiment to in...
Glucagon-like peptide-1 (GLP-1) is a hormone consisting of 31 amino acids. It is secreted by specialised intestinal epithelial cells known as L cel...
(a) The fruit fly, Drosophila melanogaster, feeds on sugars found in damaged fruits. A fruit fly with normal features is described as wild type. I...
(a) In continuous variation, a population shows a range of phenotypes between two extremes with no distinct groups. Height and mass are examples of...
(a) Describe how the structure of a mitochondrion is related to its function. (b) Explain how rice is adapted to grow with its roots submerged in ...
(a) Explain how different types of gene mutation can affect the phenotype and outline the effects of the mutant alleles that cause Huntington's dis...
Fig. 1.1 is a diagram of a part of a sarcomere in striated muscle. [Figure 1.1]
Cells can maintain a different concentration of ions within the cell compared with the extracellular environment. It is estimated that animals may ...
Fruit flies of the genus Bactrocera are pests that damage fruit crops. Table 3.1 gives the names and geographical ranges of Bactrocera fruit flies ...
Bt maize has been genetically engineered to resist insect attack. In 2019, Bt maize formed 83% of the maize grown in the USA. Outline how the genet...
Photosynthesis is a process that results in the synthesis of complex organic molecules. Respiration is a process that involves the breakdown of com...
(a) The bottlenose dolphin, Tursiops truncatus, is an aquatic mammal. It has adaptations to conserve heat when swimming in cold water. Fig. 6.1 sho...
(a) Haemoglobin is made of two α-globin chains and two β-globin chains. A person may have a mutation in the gene coding for β-globin. This is due t...
Explain what is meant by stabilising selection.
The enzyme ẞ-galactosidase catalyses the breakdown of the compound ONPG (o-nitrophenyl 1-D-galactopyranoside) to the compound ONP (o-nitrophenyl), ...
Inheritance of flower colour and flower position in pea plants are controlled by two genes. • Gene P/p controls flower colour. Allele P for purple...
The enzyme catalase catalyses the reaction shown in Fig. 1.1. catalase hydrogen peroxide → water + oxygen [Figure 1.1] A student had read that co...
Inheritance of petal colour and pollen shape in sweet pea plants are controlled by two genes. • Gene P/p controls petal colour. Allele P for purpl...
When bananas ripen, they turn brown in colour. This is due to the formation of a brown product called melanin. The enzyme catechol oxidase acts on ...
Inheritance of wing shape and eye colour in the fruit fly, Drosophila melanogaster, is controlled by two genes. • Gene N/n controls wing shape. All...
The photomicrograph shows a bronchiole and alveoli. The magnification of the image is ×360. What is the maximum diameter of the bronchiole lumen?
A specimen is observed twice with a microscope, firstly using green light with a wavelength of 510 nm and then using red light with a wavelength of...
What is found in chloroplasts and mitochondria?
Which feature is correct for all known viruses?
Four extracts from different plant materials were made and tested with Benedict's solution. The extracts were boiled with Benedict's solution for ...
Which have properties that are dependent on hydrogen bonds? 1 cellulose 2 a molecule of haemoglobin 3 water
Which statement is correct?
The diagram shows two amino acids. Some of the hydrogen atoms are numbered 1 to 6. [Figure showing two amino acid structures with H atoms numbered ...
A student wrote four statements about water. 1 Water has a high specific heat capacity which maintains the temperature of water within cells. 2 Ma...
Typical enzymes are large globular proteins with a specific tertiary shape. Which molecular interactions are directly involved in maintaining the ...
Which statement about the Michaelis–Menten constant (Km) is correct for an enzyme with a low affinity for its substrate?
Long chain, saturated fatty acids change from solid to liquid at higher temperatures compared with short chain, unsaturated fatty acids. Which fat...
When animal cells are cultured, salt solution is added to keep the cells alive. What is the purpose of the salt solution?