28 questions · 82 marks · ≈ 1 hour · spans 28 of 68 topics
Assembled from the topic question banks — not an official Cambridge International paperThe photomicrograph shows a plant cell. A student was asked to identify three observable features from the micrograph.
Which of the following would be correct labels for this image?
Choose your answer
Nucleus, permanent vacuole, capsule
Ribosomes, nucleus, nucleolus
Nucleus, chloroplasts, mitochondria
Nucleus, endoplasmic reticulum, cell wall
A group of students tested four solutions by heating them with Benedict’s reagent. The table below shows the students’ observations after testing.
Which solution contains a non-reducing sugar?
| heated with Benedict’s reagent | boiled with hydrochloric acid, neutralised and then heated with Benedict’s reagent | |
|---|---|---|
| A | orange | blue |
| B | orange | orange |
| C | blue | orange |
| D | blue | blue |
Choose your answer
Which of the statements below correctly describes a disaccharide?
Choose your answer
Sugars formed from two subunits joined together by a covalent bond that forms during a hydrolysis reaction.
Sugars formed from two subunits joined together by a glycosidic bond that forms during a hydrolysis reaction.
Sugars formed from two subunits joined together by a glycosidic bond that forms during a condensation reaction.
Starches formed from two subunits joined together by a covalent bond that forms during a condensation reaction.
Two amino acids, both containing two carboxylic acid (-COOH) groups are illustrated below.
Which labelled groups take part in the formation of a dipeptide of these amino acids?
Choose your answer
1 and 5
2 and 3
2 and 4
1 and 4
During winter when temperatures drop below freezing (0 °C), fish are able to survive in lakes.
Why is this possible?
Choose your answer
Fish use energy from food to increase their body temperature.
The sun warms stones on the lake floor which then heat the water.
Fish can produce an enzyme that stops their blood from freezing.
Ice on the surface of the lake insulates the water below.
In an experiment, students were trying to determine the amount of starch in different types of flour. They blended equal amounts of the different foods in 100 cm3 of water and then added iodine to each of the solutions. They then took a sample from each of the blended food mixtures and analysed them with a colourimeter. The colourimeter was set to measure the percentage transmission of dark blue light.
The graph below shows their results:
Which food substance contained the most starch?
Choose your answer
Rye flour
Maize flour
Wheat flour
Oat flour
Pepsin is a digestive enzyme present in the stomach of humans. The stomach environment has a pH of 2.5. Pepsin is most active in acidic environments between pH 1.5 to 2.5. The optimum temperature of pepsin is between 37°C and 42°C.
Which of the following statements is not true?
Choose your answer
Raising the pH of the stomach will decrease pepsin activity.
Above 42°C the bonds in pepsin begin to break.
Above pH 2.5 the tertiary structure of pepsin is changed.
Temperatures below 37°C result in more enzyme/substrate complex being formed.
An increase in which bond type will increase the fluidity of the cell surface membrane?
Choose your answer
hydrogen
C – O – C
C – N
C = C
Which mode of transport is energy independent?
Choose your answer
diffusion
active transport
exocytosis
endocytosis
What of the following does not happen in an animal cell cycle?
| 1 | DNA is expressed |
|---|---|
| 2 | spindle is formed from microtubules |
| 3 | cell plate forms to divide daughter cells |
Choose your answer
3 only
1 and 3 only
2 only
none
What would be the result of analysing a DNA molecule 14 000 base pairs in length?
Choose your answer
28 000 pentose sugars, 14 000 phosphates, an equal ratio of cytosine to thymine bases and an equal ratio of guanine to adenine bases
28 000 pentose sugars, 28 000 phosphates, an equal ratio of cytosine to guanine bases and an equal ratio of thymine to adenine bases
14 000 pentose sugars, 28 000 phosphates, an equal ratio of cytosine to thymine bases and an equal ratio of guanine to adenine bases
28 000 pentose sugars, 28 000 phosphates, an equal ratio of cytosine to thymine bases and an equal ratio of guanine to adenine bases
Which of the following biological molecules are required for translation?
Choose your answer
amino acids, DNA and ribosomes
ribosomes, mRNA and protein synthase
mRNA, RNA polymerase and ribosomes
ribosomes, mRNA and tRNA
The diagram shows a transverse section of a plant structure.
Which row correctly identifies the structures labelled 1, 2, 3 and 4?
| 1 | 2 | 3 | 4 | |
|---|---|---|---|---|
| A | cuticle | xylem | phloem | pith |
| B | cuticle | phloem | xylem | pith |
| C | epidermis | xylem | phloem | cortex |
| D | epidermis | phloem | xylem | cortex |
Choose your answer
Which of the following statements indicates that the mass flow of sap in the phloem is an active process?
Choose your answer
Sap in the phloem can move against the pull of gravity
Sucrose enters the phloem against its concentration gradient
Movement of sucrose in the phloem occurs against its concentration gradient
Water enters the phloem via osmosis
Figure 1 below shows a red blood cell with an actual size of 8 µm.
Each small division on the ruler is 1 mm.
How many times has the cell been magnified?
Choose your answer
6625
6.625
662.5
66.25
The Bohr effect describes a relationship between haemoglobin, oxygen and carbon dioxide.
Which statement best describes this effect?
Choose your answer
In low partial pressure of oxygen and high partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen decreases.
In high partial pressure of oxygen and high partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen increases.
In low partial pressure of oxygen and low partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen is unchanged.
In high partial pressure of oxygen and low partial pressure of carbon dioxide, the affinity of haemoglobin for oxygen decreases.
The graph shows the pressure in different parts of the heart during one cardiac cycle
At which point does the semilunar valve of the aorta close?
Choose your answer
Emphysema is a lung disease that results in the alveoli being unable to return to their original shape after inhalation. Stages in the development of emphysema are shown in the diagram below.
What correctly identifies 1, 2 and 3?
| 1 | 2 | 3 | |
|---|---|---|---|
| A | phagocytes | alveoli | elastase |
| B | phagocytes | bronchiole | ligase |
| C | lymphocytes | alveoli | elastase |
| D | lymphocytes | bronchiole | ligase |
Choose your answer
Over 40% of the world’s population live in areas where they are at risk of malaria infection. The number of cases of malaria in Africa in particular has increased in recent years.
Which of these social factors is increasing the spread of malaria?
Choose your answer
migration of people due to war
an increase in drug-resistant forms of malaria
no financially viable vaccine available
climate change
Which of the following practices have contributed to the fall in antibiotic effectiveness in the late 20th and early 21st centuries?
Choose your answer
All of them
2, 3 and 4
1 and 2
1, 2 and 4
In the immune response, which cells become memory cells?
| 1 | phagocytes |
|---|---|
| 2 | T-lymphocytes |
| 3 | B-lymphocytes |
Choose your answer
1, 2 and 3
1 and 2 only
2 and 3
1 only
The statements below refer to the functions of antibodies.
Which of these statements are not correct?
| 1 | Antibodies can combine with viruses inside cells to prevent them from damaging cells. |
|---|---|
| 2 | Antibodies can attach to flagella to make the bacteria less mobile. |
| 3 | Antibodies with single binding sites can cause agglutination of bacteria. |
| 4 | Antibodies can, with other molecules, make holes in the cell walls of bacteria. |
| 5 | Antibodies can coat bacteria to mark them for phagocytosis. |
| 6 | Antibodies can neutralise toxins. |
Choose your answer
1, 2 and 6
1 and 6
2, 3 and 5
1 and 3
The Fig. 1 represents a stage of aerobic respiration.
Fig. 1
(i) Identify the specific part of a cell shown in Fig. 1.
(1 mark)
(ii) Identify the stage of respiration represented by Fig. 1.
(1 mark)
(iii) Identify the molecules labelled P and Q in Fig. 1.
(2 marks)
Extract:
The Fig. 1 represents a stage of aerobic respiration.
Fig. 1
Describe process W in Fig. 1. You should use the full names of molecules X, Y and Z in your answer.
Extract:
The Fig. 1 represents a stage of aerobic respiration.
(ii) The stage of respiration represented by Fig. 1 is:
(iii) The molecules labelled P and Q in Fig. 1 are:
Process W can be described as follows:
The rate at which the process shown in Fig. 1 takes place is affected by temperature.
Explain why this is the case.
NAD is an example of a coenzyme.
Give one other example of a coenzyme involved in aerobic respiration.
The concentration of carbon dioxide gas in the air of a woodland changes over 24 hours. Carbon dioxide concentrations can also vary depending on the height above the ground at which a gas measurement is taken.
Explain the variation in carbon dioxide concentration in woodland over time and at different heights. Assume that there is no air movement caused by wind throughout the 24 hours.
A team of researchers investigated the effect of changing the carbon dioxide concentration on the levels of glycerate-3-phosphate (GP) and ribulose bisphosphate (RuBP) in photosynthesising cells.
Table 1 shows the results obtained when the carbon dioxide concentration was reduced.
Table 1
| Photosynthetic intermediate | Level before experiment / arbitrary units | Level after experiment / arbitrary units | |
|---|---|---|---|
| 1.0% CO2 | 0.003% CO2 | ||
| RuBP | 18 | 18 | 37 |
| GP | 36 | 36 | 17 |
Explain the results for RuBP and GP at 0.003% carbon dioxide concentration.
Extract:
A team of researchers investigated the effect of changing the carbon dioxide concentration on the levels of glycerate-3-phosphate (GP) and ribulose bisphosphate (RuBP) in photosynthesising cells.
Table 1 shows the results obtained when the carbon dioxide concentration was reduced.
Table 1
| Photosynthetic intermediate | Level before experiment / arbitrary units | Level after experiment / arbitrary units |
| 1.0% CO2 | 0.003% CO2 |
| RuBP | 18 | 18 | 37 |
| GP | 36 | 36 | 17 |
The researchers carried out a similar experiment but increased the carbon dioxide concentration from 1.0 % to 2.0 %. The relative levels of GP and RuBP remained the same both before and after the experiment.
Explain two reasons why this might be the case.
A student investigated the effect of different wavelengths of light on the rate of photosynthesis in a suspension of algal cells.
The apparatus used is shown in Fig. 1
Fig. 1
State the measurements the student should take to determine the rate of photosynthesis using the equipment shown in Fig. 1.
Extract:
A student investigated the effect of different wavelengths of light on the rate of photosynthesis in a suspension of algal cells.
The student did not use a pH buffer to maintain a constant pH.
Explain how the pH of the suspension would change over time in the absence of a pH buffer.
Extract:
A student investigated the effect of different wavelengths of light on the rate of photosynthesis in a suspension of algal cells.
Fig. 2 shows the student's results.
Fig. 2
(i) Explain why the rate of photosynthesis peaks at 460 nm and 660 nm.
(2 marks)
(ii) Explain whether the graph in Fig. 2 shows an absorption spectrum or an action spectrum.
(1 mark)
The student extended the investigation by measuring the effect of salt concentration on oxygen production within algae chloroplasts. Fig. 3 shows the results.
Fig. 3
(i) Identify the precise stage of photosynthesis in algae chloroplasts that is affected by an increased salt concentration.
(1 mark)
(ii) Using information in Fig. 3, explain the effect that increasing salt concentration has on oxygen production in algae chloroplasts.
(2 marks)
(iii) Explain how the effect shown in Fig. 3 will affect other aspects of the photosynthesis reactions.
(3 marks)
Some diabetic individuals do not produce insulin. In an experiment, a woman with diabetes drank a sugary solution. The glucose concentration in her blood was measured at regular intervals. The results are shown in Fig. 1.
Fig. 1
Suggest two reasons why the concentration of glucose decreased after 60 minutes even though this woman’s blood contained no insulin.
Extract:
Some diabetic individuals do not produce insulin. In an experiment, a woman with diabetes drank a sugary solution. The glucose concentration in her blood was measured at regular intervals. The results are shown in Fig. 1.
Fig. 1
The same experiment was repeated on a non-diabetic patient. The glucose concentration in their blood prior to drinking the sugary solution was 75 mg per 100 cm3.
(i) Sketch a curve on Fig. 1 to show the results you would predict.
(1 mark)
(ii) Outline the reason for the curve that you have sketched in part (i).
(3 marks)
The regulation of glucose is an example of a homeostatic mechanism. Another example of a homeostatic mechanism is osmoregulation.
Describe the role of ADH in osmoregulation.
Fig. 1 shows an electron microscope image of two guard cells.
Fig. 1
Give two features other than the stomatal pore that help to identify the cells in Fig. 1 as guard cells.
Extract:
Fig. 1 shows an electron microscope image of two guard cells.
If the guard cells in Fig. 1 were living, suggest the environmental conditions that might be present.
Extract:
Fig. 1 shows an electron microscope image of two guard cells.
Explain the process that would cause the size of the stomatal pore in Fig. 1 to increase.
Explain how a cholinergic synapse functions.