Topic 1: Cell biology 
This page contains multiple choice questions in the style of Paper 1 of the Biology exams.
They test the breadth of your knowledge of the understandings and skills about cell biology.
To spend more time reviewing the topic before answering these questions, use the revision resources.
Cell biology revision resources
This page lists the understandings and skills expected for Topic 1 and links to the sub-topic pages which contain detailed revision notes, activities and past paper style questions. Great for revision.
Learn from any mistakes. Every question has an examiner's explanation that appears when you check your answers.
Pasteur's experiment with 'swan neck' flasks showed that a sterile nutrient medium exposed to the air would not show any signs of bacterial growth under his conditions.
What prevented the growth of bacteria?
Pasteur's famous experiments with swan neck flasks showed that broth kept in a flask where no dust could settle in the nutrient medium, and thus no living cells could get in, would not go mouldy.
This disproved the theory of spontaeous generation.
What is the best definition of endosymbiosis?
Endosymbiosis is where a cell engulfs another cell and it continues to live inside the cell.
The engulfed cell provides something for the host cell, and gets something in return. Both cells benefit.
Which cells are produced when a diploid cell divides by mitosis?
Mitosis is division of the nucleus into two genetically identical daughter nuclei in eukaryote cells.
A diploid cell will produce two diploid daughter cells in one division of mitosis.
The image below was taken in 1825 and shows part of the cell cycle.
What type of cells is this and at which stage of the cell cycle?
Cytokinesis occurs after mitosis in plant and animal cells. The chromosomes are uncoiled.
Plant cells build a new cell wall which divides the cytoplasm.
Animal cells form a cleavage furrow (likes a wasps waist) as they don't have cell walls.
The image below shows two cells undergoing mitosis.
Which of the following correctly identifies the stage of mitosis for each of the cells?
Identification of the phase of mitosis is an important skill.
The position of the chromosomes gives the best clue.
In Prophase, they are spread around the cell, and double stranded.
In Metaphase, the chromosomes are lined up on the spindle equator.
In Anaphase, the chromosomes are moving to opposite poles of the cell.
In Telophase, the two groups of chromosomes are separate, sometimes with a nuclear membrane.
This box contains a lung waiting for a transplant operation.
What is special about the solution inside the box which surrounds the tissue?
Tissues and organs must be kept in a solution with the same osmolarity as the cytoplasm of the cells to prevent osmosis. If they were kept in pure water, osmosis would carry water into the cells and they would burst, causing damage to the cells. If the solution was hypertonic, the tissue would lose water (and gain ions).
The four cells shown below have each been surrounded by a solution for 1 hour.
Which cells have been in a hypertonic solution ?
Cell A is swollen turgid, it is in a hypotonic solution or an isotonic solution.
The cells B, C and D show increasing signs of plasmolysis, and so they must be in hypertonic solutions.
Skill: Estimation of osmolarity in tissues by bathing samples in hypotonic and hypertonic solutions. (Practical 2)
The photograph is from an electron microscope image of a membranes.
Parallel dark lines are clearly seen.
In electron micrography, heavy metal stains are often used to enhance contrast. DNA and Proteins often show as dark areas because these molecules can attach to the stain.
Which of the following interpretations is most similar to the proposal of the Daveson-Danielli model of membranes?
Students are expected to know how to use evidence from electron microscopy to support an idea about membranes. One illustration of this is the proposal of the Davson-Danielli model.
Further evidence lead to the falsification of the Davson-Danielli model and the proposal of the fluid mozaic model.
The electron microscope image below shows three organelles found in an animal cell.
What is the name of the organelles?
Know how to idenfity the organelles in eukaryotes and draw their compartmentalised structure.
A mitochondrion (pleural = mitochondria) has an outer membrane and inner membrane folded into long thing 'flaps' called cristae.
The electron microscope image below shows a ciliated epithelial cell from the trachea.
What is the name of the organelle labelled X?
What are the structures labelled X and Y likely to be in this electron microscope image?
Students are expected to be able to identify organelles from microscope images of cells. The nucleus is distinctive because it is about 10µm in size, and it has black dots in it, chromatin, and sometimes one or more dark patches within the nuclear membrane. It also has a double membrane, not often easily visible.
Why is it that prokaryotes can divide by the simple process of binary fission, but eukaryotes have to divide by the more complex process of mitosis?
To explain how the structure of prokaryotes allows them to divide by binary fission you could mention:
- Prokaryotes have a single chromosome, eukaryotes have multiple chromosomes
- Prokaryotes have no nuclear membrane, which eukaryotes have.
There are seven processes which are said to be possessed by all living things.
This sweet pea plant has grown a tendril around some string, to help support its upward growth.
Which of the characteristics of living things is illustrated in this photo?
The characteristics of living things (Mr H. Gren - metabolism, response, , homeostasis, growth, reproduction, excretion & nutrition)
The fly is responding to the closing trap, and the trap has responded to the presence of the fly.
What is the importance of surface area to volume ratio to cells?
Surface area to volume ratio is important in the limitation of cell size. The lager the volume, the greater the need for materials which have to be exchanged over the surface of the cell.
The blood cells below were imaged using an electron microscope.
The magnification is x3000 and the ruler measures the central cell as being 2 cm in diameter.
Estimate the actual size of this white blood cell.
Calculate specimen size using magnification?
First change the size measurement into µm units = 20000µm
Then divide by the magnification. 20000 / 3000 = 20 / 3 = 6.6 µm
Which phrases most accurately describe a multicellular organism?
Comment: The multicellular condition allows for differentiation into cells of different types and also replacement of cells when injured or damaged.
The diameter of this field of view under a microscope at X400 magnification is 250 μm.
The image below shows Dracaena leaf upper epidermis cells.
Which is the best estimate of the width (from left to right) of an epidermal cell?
Comment: There are approximately 8 cells across a diameter so 250/8 = 33 μm.
Beware of the units, mm are 1000 times bigger than µm.
The diagram shows a typical eukaryotic plant cell. Which organelles are involved in supporting the cell and plant? I Cell wall II Cytoplasm III Nucleus IV Vacuole.
The cell and plant are supported by the turgor pressure of water in the vacuole acting on the rigid cell wall.
Which organelles are found in large numbers in secretory cells in animals? I Vesicles II Golgi Body III Mitochondria IV Rough endoplasmic reticulum.
Secretory cells synthesise proteins for exocytosis so have large numbers of mitochondria to supply energy, RER to synthesise the proteins for packaging into vesicles by the Golgi Body.
Which of the following is the best description of an organelle?
The "wrong" answers are correct statements but are distractors, not the best description.
Refresh this page to try a new set of 20 multiple choice questions. The questions will be different next time you visit. Great revision.
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