Woodlice are small organisms that live in damp places.
In an experiment, three live woodlice are put into a glass container. The diagram shows what happens after 30 minutes.
Which species can breed with Prunella vulgaris to produce fertile offspring?
What is the correct order of arthropod groups, from those with the most legs to those with the fewest legs?
The diagram shows four animal cells, as seen under a light microscope.
What will be present at X?
The diagram shows a root hair cell.
How is this cell modified for the absorption of water?
A student draws a diagram of a mitochondrion.
The diagram has a magnification of x20 000.
The diagram is 5 cm long.
What is the actual size of the mitochondrion?
A jar of air was placed upside down on top of a jar containing a brown gas as shown.
Which process has taken place?
Which row describes active transport?
The bases on one strand of a DNA molecule have the sequence CAGCT.
What is the sequence of bases on the other strand?
The graph shows the effect of temperature on the rate of an enzyme-controlled reaction.
Which statements are correct?
1 The collision frequency between substrate and enzyme increases between X and Y.
2 The shape of the active site is altered between Y and Z.
3 The enzyme is denatured irreversibly at X and Z.
Which graph represents the effect of pH on the activity of a digestive enzyme?
In which process is oxygen a waste product?
Which layer in the leaf contains interconnecting air spaces?
Where does egestion take place?
The diagram shows a fat globule (P) in one part of the alimentary canal and the same fat globule (Q) as it appears in another part of the alimentary canal.
In which parts of the alimentary canal are P and Q found?
The diagram shows enzymes and the products of the reactions they catalyse.
Which diagram matches the enzymes with the correct products?
Which statement about a function of xylem tissue is correct?
What is part of the definition of transpiration?
The diagram shows the circulation of blood in an organism.
In which part of the organism is the location of the capillaries in the box?
The photomicrograph shows human blood.
Which blood component can carry out the process of phagocytosis?
Which diagram shows how a vaccination can lead to long-term immunity?
Air entering human lungs contains approximately 21% oxygen and 0.04% carbon dioxide.
Which row shows the concentrations of these gases in air leaving the lungs?
After running a fast race a student had pains in their leg muscles.
The pain was caused by the build-up of a product of anaerobic respiration.
Which product caused the pain?
The diagram shows the production and excretion of materials from the human body.
What are V, W, X, Y, and Z in the diagram?
What is a function of a synapse?
Hormones and the nervous system both control our bodies.
Which statement about the control provided by our hormones is correct?
Auxin is a chemical produced by plants. It controls plant growth.
Which statement about auxin is correct?
How do some antibiotics kill bacteria?
Some statements about asexual reproduction are listed.
1 Offspring are genetically identical.
2 Offspring are genetically different.
3 Only one parent is required.
4 Two parents are required.
Which types of contact between humans can spread HIV?
1 blood transfusions
2 sexual intercourse
3 saliva
Which method of birth control works by preventing an egg from being released?
What is defined as ‘a thread-like structure of DNA, carrying genetic information in the form of genes’?
The statements describe steps in protein synthesis.
1 Copies of the gene are carried to the cytoplasm as mRNA molecules.
2 Each ribosome assembles amino acids into a protein molecule.
3 The gene coding for a protein is copied in the nucleus.
4 The mRNA molecules pass through ribosomes.
Which sequence of steps is correct?
A sunflower has 17 chromosomes in each pollen nucleus. These nuclei are produced by the process of ……1…… in the anthers. They are genetically ……2…… all the pollen nuclei produced by those anthers. After fertilisation the resulting zygote will have ……3…… chromosomes.
Which row correctly completes gaps 1, 2 and 3?
A man heterozygous for the sickle cell anaemia allele has children with a woman who is homozygous for the normal haemoglobin allele,
What is the probability that the first child will be resistant to malaria?
Which leaf feature is an adaptation of xerophytes to their environment?
The graph shows the change in population of an organism over time in an ecosystem.
Which row correctly identifies each phase of the population graph?
The diagram shows the structure of a bacterium.
The presence of structure X is one reason why bacteria are used in genetic engineering.
What is structure X?
When nitrates enter a lake they cause rapid growth of algae on the surface of the water. This causes the following changes in the lake:
1 The concentration of dissolved oxygen in the water decreases.
2 Fish and other aquatic animals die.
3 Aerobic respiration in decomposers increases.
4 Producers die and decomposition increases.
In which order do these changes occur?
The action of which type of bacteria would cause soil to be lacking in nitrates?