Biology 9700 · AS & A Level
The microscope in cell studies
100 practice questions on The microscope in cell studies, with worked solutions and instant marking.
A student has produced a drawing of a cell structure as observed with a light microscope. The drawing has a magnification of $\times 600$. On the drawing, the structure measures $6\ \text{mm}$. What is the true length of the cell structure?
Feb/March 2016
The diagrams illustrate transverse sections of parts of a plant. In the transverse sections, which tissues move sucrose?
Feb/March 2016
The photomicrograph shows a cross-section of part of a bronchus wall. What function does the tissue labelled X have?
Feb/March 2016
Which of the following raise the chance of catching TB?
Feb/March 2016
One way to lower the spread of malaria is to apply an insecticide. This may be used to treat mosquito nets. A further control method is to cover water surfaces entirely with insoluble polystyrene balls that remain floating. From this information, what are the reasons for these control methods?
Feb/March 2016
Which units are most suitable for recording the diameters of a lymphocyte and a red blood cell?
Feb/March 2016
A light microscope is used to view two structures separated by $200\ \text{nm}$. What is the distance between the structures when the magnification changes from $\times 40$ to $\times 400$?
Feb/March 2017
The diagram illustrates a stage micrometer scale as seen through an eyepiece that contains a graticule. Each of the smaller divisions on the stage micrometer scale measures $0.1\ \text{mm}$. A slide of a plant cell is used instead of the stage micrometer scale. What is the length of the nucleus in the plant cell?
Feb/March 2017
As blood moves from an artery to a vein, the wall thickness of the vessels changes. Which bar chart shows these changes correctly?
Feb/March 2017
An eyepiece lens in a microscope may be fitted with an eyepiece graticule. Which of the following statements about eyepiece graticules are correct? 1. They determine the true length of cells in micrometres. 2. They allow biologists to draw cells in the correct proportions. 3. Their size changes when the objective lens is switched from $\times 10$ to $\times 40$.
Feb/March 2018
A student was told to use the scale bar shown to work out the magnification of a cell in a photomicrograph. The scale bar shows $2\,\mu\text{m}$. Which method could the student use to calculate the magnification of the cell?
Feb/March 2018
The photomicrograph reveals a transport tissue in the stem of a grape vine. Which structure is labelled T?
Feb/March 2018
Which combination of eyepiece and objective lens in a light microscope permits the largest number of cells to be seen in one field of view?
Feb/March 2018
The diagram below was produced from an electron micrograph of an animal cell. Which diagram would show the same cell as it would appear under a simple light microscope, with daylight as the only illumination source?
Feb/March 2019
In a diagram, the diameter of a red blood cell was measured to be $2.5\ \text{cm}$. Its true diameter was $7\ \mu\text{m}$. Which calculation would produce the correct magnification of the red blood cell shown in the diagram?
Feb/March 2019
The photomicrograph shows a section through a structure found in mammals when viewed under a light microscope. What are the principal components of layer W?
Feb/March 2019
The diagram depicts a fin whale drawn to scale. A student wrote three statements about the diagram. Which of the statements are correct?
Feb/March 2019
The statements below list some events in the cardiac cycle. They are not arranged in the correct sequence. Which statement describes the second event to happen in the cardiac cycle?
Feb/March 2019
The photomicrograph displays onion cells. The true length of the onion cell marked Y is $350\,\mu\text{m}$. What magnification does the photomicrograph have?
Feb/March 2021
Which cell organelles can be seen clearly when a light microscope is used at high power $(\times 400)$?
Feb/March 2022
Some students were shown a photomicrograph of a cross-section of an unfamiliar material and asked to state what they could observe. They described the cross-section of F as: 1 circular, 2 a hollow tube, 3 spherical. Which descriptions of the cross-section of F correctly state what the students could actually observe?
Feb/March 2022
This photomicrograph shows a plant cell. The cell measures $25\,\mu\text{m}$ across from X to Y. What magnification does the photomicrograph have?
Feb/March 2022
The diagram shows a cross-section of a mammalian heart. Which heart chambers are shown by G and H?
Feb/March 2022
During one cardiac cycle, the highest pressure in each of the four chambers of a healthy human heart was measured. The highest pressures obtained were 3 mm Hg, 10 mm Hg, 25 mm Hg and 120 mm Hg. Which of these values was measured for the right ventricle?
Feb/March 2022
The graph illustrates how the pressure varies in three structures on the right side of the heart throughout the cardiac cycle. What does the line labelled T show?
Feb/March 2022
The photomicrograph shows a transverse section of part of the gas exchange system of a mammal. What does the line labelled V indicate?
Feb/March 2022
At birth, what kind of immunity does a baby possess?
Feb/March 2022
The photomicrograph displays cells taken from a human blood smear. Which calculation correctly determines the actual diameter of the neutrophil visible in the photomicrograph in micrometres ($\mu\text{m}$)?
Feb/March 2023
A student used a stage micrometer to calibrate an eyepiece graticule. The stage micrometer had divisions of $0.01\,\text{mm}$ each. When the objective lens was set to $\times 10$, 10 eyepiece graticule units lined up with 10 divisions on the stage micrometer. The same microscope was then fitted with a $\times 40$, rather than a $\times 10$, objective lens to measure the diameter of an alveolus. This diameter was measured as 96 eyepiece graticule units. The eyepiece lens was left unchanged. What is the best estimate for the diameter of the alveolus?
Feb/March 2023
The photomicrograph displays a section of tissue containing an artery. Which row correctly identifies the type of artery and whether the blood inside it is oxygenated or deoxygenated?
Feb/March 2023
A student used a light microscope to view a blood smear on a microscope slide. An eyepiece graticule was used to measure the diameter of a white blood cell on the slide. The student noted that the white blood cell measured $5$ eyepiece graticule units across. Which further piece of information does the student need in order to find the diameter of the white blood cell in micrometres?
Feb/March 2024
Why must an electron microscope be used to observe the cristae of a mitochondrion?
Feb/March 2024
Measles is an infectious disease, and a virus causes it. The graph shows the annual number of measles cases in a country before and after a vaccine was introduced. What might have led to the decrease in the number of measles cases after vaccination was introduced?
Feb/March 2024
On an electron micrograph, the measured length of a mitochondrion is $17.1\ \text{cm}$. The magnification of the electron micrograph is $\times 38\,000$. What is the mitochondrion’s actual length?
Feb/March 2025
The scanning electron micrograph displays the inner lining of a human trachea. What is the name of the part of the electron micrograph labelled T?
Feb/March 2025
Which rows accurately summarise the usual distribution of cartilage and smooth muscle in the different regions of the human gas exchange system?
Feb/March 2025
Which structures are quantified in these units?
May/June 2010
The diagram shown below is taken from an electron micrograph of an animal cell. Which option shows the same cell as it would appear under a light (optical) microscope at $400$ magnification?
May/June 2010
The diagram depicts a stage micrometer, whose divisions are spaced $0.1\text{ mm}$ apart, as seen through an eyepiece with a graticule. What is the area of the microscope’s field of view at this magnification? $(\pi = 3.14)$
May/June 2010
The diagram represents a tropical ocean food chain, and the efficiency of energy transfer between trophic levels is 10\%. phytoplankton → herbivorous zooplankton → carnivorous zooplankton → small fish → tuna. The net primary production of phytoplankton is $1300\,\text{g m}^{-3}\,\text{yr}^{-1}$. What is the net primary production each year for the carnivorous zooplankton and the tuna?
May/June 2010
In experiments, which measuring methods are affected by parallax error?
May/June 2010
The diagram below has been taken from an electron micrograph of an animal cell. Which option shows that same cell as it would appear under a light (optical) microscope at $\times 400$ magnification?
May/June 2010
Which structures are being measured by these units?
May/June 2010
The diagram presents a spirometer trace showing tidal volume and vital capacity. What changes occur to the volumes labelled X and Y during moderate exercise?
May/June 2010
The diagram depicts a stage micrometer with divisions spaced $0.1\,\text{mm}$ apart, as seen through an eyepiece that has a graticule. What is the area of the microscope’s field of view at this magnification? $(\pi = 3.14)$
May/June 2010
In experiments, which measurement methods are affected by parallax errors?
May/June 2010
The diameter of a cell organelle is $4 \times 10^{-1}\,\text{mm}$. What is the diameter in $\mu\text{m}$?
May/June 2011
Which rows indicate the chemical groups found in the biological molecules listed?
May/June 2011
In the table below, which option gives the correct comparison of light microscopes and electron microscopes?
May/June 2011
Which row correctly states the structure of an artery in comparison with a vein when viewed in transverse section with a light microscope?
May/June 2011
A student was asked to state the differences seen on four microscope slides of sections from different regions of the gas exchange system. slide 1: cartilage and glands absent; few goblet cells, ciliated epithelial cells and smooth muscle present slide 2: incomplete cartilage rings, glands, goblet cells, ciliated epithelial cells and smooth muscle present slide 3: cartilage, glands, goblet cells and smooth muscle absent; squamous epithelial cells present slide 4: plates of cartilage, glands, goblet cells, ciliated epithelial cells and smooth muscle present Which option correctly identifies the parts of the gas exchange system?
May/June 2011
Plant cells are stained and then examined with a light microscope. Which structures would be clearly visible at a magnification of $\times 400$?
May/June 2011
With a stage micrometer scale, one division of an eyepiece graticule was found to equal $0.005\ \text{mm}$. A spongy mesophyll cell measured $3.5$ divisions on the eyepiece graticule. What is the estimated diameter of the cell?
May/June 2011
The diagram illustrates a section of a DNA molecule. How many hydrogen bonds take part in keeping these DNA strands joined together?
May/June 2011
State the approximate diameters of a trachea, an alveolus, a bronchiole and a bronchus.
May/June 2011
Which of the diseases shown in the table can be treated only with antibiotics?
May/June 2011
The lumen of a human aorta is $2\ \text{cm}$ wide. A human red blood cell has a diameter of $7\ \mu\text{m}$. If red blood cells were placed in a line end to end, how many would span the diameter of the aorta lumen?
May/June 2011
Plant cells are stained before being examined with a light microscope. Which structures would be visible clearly at a magnification of $\times 400$?
May/June 2011
In the table below, which comparison between light and electron microscopes is correct?
May/June 2011
A person with mild emphysema gave up smoking cigarettes. Why would this person’s health get better?
May/June 2011
A student had to compare four microscope slides showing sections from different regions of the gas exchange system. Slide 1: missing - cartilage, glands; seen - few goblet cells, ciliated epithelial cells, smooth muscle. Slide 2: seen - incomplete cartilage rings, glands, goblet cells, ciliated epithelial cells, smooth muscle. Slide 3: missing - cartilage, glands, goblet cells, smooth muscle; seen - squamous epithelial cells. Slide 4: seen - plates of cartilage, glands, goblet cells, ciliated epithelial cells, smooth muscle. Which option correctly identifies the parts of the gas exchange system?
May/June 2011
Which disease is least likely to be transmitted directly from parent to child?
May/June 2011
An organelle inside a cell has a diameter of $4 \times 10^{-1}$ mm. What diameter does this represent in $\mu\text{m}$?
May/June 2011
Which set of structures can be seen in an appropriately stained plant cell with a high power ($\times 400$) light microscope?
May/June 2012
The photomicrograph has a magnification of $\times 4000$. What is the real size of the nucleolus?
May/June 2012
A microscope can resolve details down to $200\,\text{nm}$. Which of the following organelles would not be resolved by this microscope?
May/June 2012
A student was instructed to sketch a plan diagram of the plant tissue visible in the photomicrograph and label two features that can be seen. Which annotations are correct?
May/June 2012
What factor limits the resolution of the light microscope?
May/June 2012
The diagram shows an electron micrograph of virus particles inside a human nucleus. What is the diameter of the virus particles that are labelled?
May/June 2012
What is the ecological meaning of the term community?
May/June 2012
The diagram illustrates how energy moves through an ecosystem. Gross productivity is shown by photosynthesis. Producers use some energy in respiration, and the energy remaining is the net productivity. This may also be written as the equation: net productivity = gross productivity - respiration. A fraction of the net productivity is transferred to herbivores. Which calculation shows the fraction of net productivity transferred to herbivores?
May/June 2012
For each graph set, the data are arranged for blood vessels in this order: artery → arterioles → capillaries → venules → veins. Which set is correct? The variables plotted are total cross-sectional area, velocity, wall thickness, and pressure.
May/June 2012
What would an electron micrograph of a bronchus wall show?
May/June 2012
Which set of structures can be seen in a plant cell that has been suitably stained when a high power (\times400) light microscope is used?
May/June 2012
A microscope has a resolution of $200\ \text{nm}$. Which organelle from the options below would not be resolved by this microscope?
May/June 2012
The magnification of the photomicrograph is \times4000. What is the real size of the nucleolus?
May/June 2012
What size ranges are visible using a light microscope?
May/June 2013
The diagram is of a mitochondrion based on an electronmicrograph. The distance from X to Y on the mitochondrion is $3000\,\text{nm}$. What magnification has been used for the drawing of the mitochondrion?
May/June 2013
Which of the following statements about coronary by-pass surgery is correct?
May/June 2013
Which advancement in vaccine production would be the most significant in efforts to eradicate measles in developing countries?
May/June 2013
Termites are insects that construct large nests containing millions of termites of the same species. These nests are common in tropical savanna, which usually has grasses and widely spaced trees. In this habitat, the termites feed on wood and other dead plant material. Which statement is correct?
May/June 2013
The diagram shows a stage micrometer whose divisions are $0.1\,\text{mm}$ apart, as seen through a microscope fitted with a graticule. What is the area of the microscope’s field of view at this magnification? $(\pi = 3.14)$
May/June 2013
A light microscope is being used to view two membranes separated by $200\,\text{nm}$. When the objective lens is switched from low power to high power $(\times 400)$, what is the distance between the membranes?
May/June 2013
The electron micrograph shows a chloroplast. The length of the chloroplast on the line indicated is $80\,\text{mm}$. The actual length of the chloroplast is $10\,\mu\text{m}$. Calculate the magnification of the chloroplast.
May/June 2013
The diagram below comes from an electron micrograph of an animal cell. Which one shows that same cell, as it would be observed with a light microscope at $\times 400$ magnification?
May/June 2013
The diagram illustrates how pressure varies in the different structures on the right side of the heart during the cardiac cycle. Which structures are shown by X, Y and Z?
May/June 2013
There is extensive epidemiological evidence that connects smoking with illness and premature death. Which option best describes the term ‘epidemiological’?
May/June 2013
The diagram illustrates a simplified nitrogen cycle. Which row gives the correct labels for P, Q, R and S?
May/June 2013
An electron microscope has greater resolution than a light microscope. What is one consequence of this higher resolution?
May/June 2013
The diagram is of a chloroplast based on an electronmicrograph. The distance of the chloroplast from X to Y is $5000\ \text{nm}$. What is the magnification of the chloroplast drawing?
May/June 2013
Eyepiece graticules and stage micrometers are used to measure cells. Which is the correct reason for calibrating an eyepiece graticule?
May/June 2013
Humans have a double circulation system. What is meant by the term ‘double circulation’?
May/June 2013
Two ecosystems, X and Y, were investigated and compared. They are the same age, and each has an identical climate. The comparison results are given in the table. From the information in the table, which statements are reasonable suggestions about X and Y?
May/June 2013
Which statement best compares an electron microscope with a light microscope?
May/June 2014
The photomicrograph shows a cross-section of two structures found in mammals, observed with a light microscope. Which row is correct?
May/June 2014
The first column of the table lists statements about disease. The columns labelled 1-4 stand for four different diseases that are named. Which set of column headings correctly matches the diseases in the table?
May/June 2014
A farmer plants a different crop in the same field in each of three years. In the fourth year, the farmer sows a leguminous crop and then ploughs it into the soil. The following year, the rotation begins once more. By the time the rotation begins again, which microorganisms will have increased in number? 1. denitrifying bacteria 2. nitrifying bacteria 3. nitrogen-fixing bacteria 4. decomposing bacteria
May/June 2014
At about what magnification does light microscopy become unsuitable because the resolution is too low?
May/June 2014
The diagram displays a stage micrometer alongside an eyepiece graticule scale, with a magnification of $\times 400$. At the same magnification, a chloroplast is measured and is found to be 4 eyepiece graticule divisions in length. How long is the chloroplast?
May/June 2014
A microscope’s eyepiece lens is fitted with an eyepiece graticule. Which of the following statements about the graticule are correct?
May/June 2014