The mitotic cell cycle — AS & A Level Biology (9700) questions by topic
Identify, deduce and explain are the command words that recur most, applied to chromosome behaviour, cell-cycle stages and enzyme-affinity reasoning: identifying which cell-cycle stage a sample of dividing cells is in from percentage data, explaining why a structural change to a nucleotide prevents phosphodiester bond formation, and linking an increase in Km to a decrease in enzyme affinity for its substrate. Deduce specifically wants a stage or aptamer picked out from given data, not a general cell-cycle description.
With 58 real questions from 2023 to 2025 papers and marks from 1 to 14, single-stage identification sits beside multi-part explanations of DNA replication and enzyme kinetics. Submitting each answer for instant marking suits this topic well, since confusing mitosis with the whole cell cycle, or naming a stage instead of a phase such as S phase, is flagged immediately.
What examiners look for
- A frequent misconception has stem cells repairing individual damaged cells, when they repair damaged tissue rather than single cells.
- A common error forgets that the nuclear membrane disappears during prophase, affecting later stage-identification answers.
- Mitosis is often confused with the entire cell cycle, particularly by weaker candidates.
- Spindle fibres are sometimes omitted from mitosis diagrams, or drawn with separated chromatids or too many chromosomes.
- Strong answers correctly identify the S phase from cell-cycle data, link increased Km to decreased RNA polymerase affinity for its substrate, and orientate chromosomes accurately at the spindle equator with sister chromatids facing opposite poles.
May–June 2025, Paper 11
A sample of 500 cells dividing by mitosis was examined to identify the stage of mitosis for each cell. The table shows the results. stage of mitosis percentage of cells in the…
Answer this question and get it marked →The diagram shows a chromosome. What are structures P and Q? P Q --- --- --- A centriole chromatid B centromere telomere C centromere centriole D centriole telomere
Answer this question and get it marked →Which processes are used by stem cells during tissue repair? 1 cytokinesis 2 DNA replication 3 transcription A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 and 3 only
Answer this question and get it marked →The enzyme telomerase prevents loss of telomeres after many mitotic cell cycles. Which cells transcribe a high concentration of telomerase? 1 neutrophils 2 mature red blood cells…
Answer this question and get it marked →May–June 2025, Paper 12
The diagram shows the arrangement of chromosomes with attached spindle fibres during a stage of mitosis. The diagram shows chromosomes aligned at the equator of a cell with…
Answer this question and get it marked →During which phase of the cell cycle does DNA replication take place? A G₁ B G₂ C M D S
Answer this question and get it marked →Human body cells in interphase have 46 chromosomes. What is correct about the number of telomeres present in prophase of a human body cell? A 46 as there is one telomere at the…
Answer this question and get it marked →May–June 2025, Paper 13
A cell has chromosomes that are not yet at the equator of the cell and each chromosome consists of two chromatids. Which stage of mitosis is this cell in? A prophase B metaphase C…
Answer this question and get it marked →A student counts the following in a cell: 5 chromosomes, 5 centromeres, 16 telomeres. Which row gives the correct totals? A 4 chromosomes, 4 centromeres, 16 telomeres B 5…
Answer this question and get it marked →May–June 2025, Paper 14
The epithelium that lines the stomach is damaged by acid and is renewed every two days. Why is mitosis required to repair the damage? A Mitosis repairs damaged cells. B Mitosis…
Answer this question and get it marked →What is the role of telomeres? A allowing the chromatids to reach the poles during mitosis B holding sister chromatids together C making sure that the sister chromatids are of…
Answer this question and get it marked →Which features of mitosis help to maintain the genetic composition of the cell? 1 the longitudinal division of the centromeres 2 the DNA of the parent cells replicates before…
Answer this question and get it marked →May–June 2025, Paper 24
In the roots of plants, specialised tissues are formed from a region in the root tip known as the root apical meristem. Fig. 1.1 shows the different regions of a root tip: zone of…
Answer this question and get it marked →May–June 2024, Paper 11
Which row is correct for stem cells? The columns are 'can repair cells' and 'can be involved in the formation of phagocytes'.
Answer this question and get it marked →Eukaryotic organisms grow and increase in size as a result of cell division. The diagram shows some stages of mitosis with one stage missing, labelled X. The first image shows a…
Answer this question and get it marked →The graphs show various distance measurements taken from the start of metaphase of mitosis. The graphs are to scale when compared to one another. Graph X shows distance staying…
Answer this question and get it marked →Which row is correct for the start of anaphase of mitosis? The columns are 'form of DNA', 'DNA is associated with histone proteins' and 'state of the cell surface membrane'.
Answer this question and get it marked →May–June 2024, Paper 12
Which metabolic processes will be very active in a cell that has just completed cytokinesis? (1) ATP formation; (2) DNA replication; (3) protein synthesis.
Answer this question and get it marked →The diagram shows a typical mitotic cell cycle and the point in the cell cycle that has been reached by each of four cells, V, W, X and Y. The cycle is divided into G1 phase, S…
Answer this question and get it marked →The graph shows the mean length of the spindle fibres during mitosis. The curve rises from zero (region A), reaches a peak (point B), then decreases (region C) back down to zero…
Answer this question and get it marked →May–June 2024, Paper 13
The contents of a daughter cell are compared to the parent cell after one cell cycle. Which row is correct? number of chromosomes volume of cytoplasm length of telomeres --- ---…
Answer this question and get it marked →A high-power photomicrograph shows a cell in a stage of mitosis. The chromosomes are visible and lined up along the cell equator but there is no nuclear envelope. Which stage of…
Answer this question and get it marked →Which statements about the cell cycle are correct? 1 The cell cycle includes interphase and mitosis. 2 DNA replication takes place in interphase. 3 A cell can remain in interphase…
Answer this question and get it marked →A scientist stains the chromosomes of a plant cell with a fluorescent dye to observe the telomeres. This cell has 38 chromosomes. How many telomeres will the scientist observe in…
Answer this question and get it marked →May–June 2024, Paper 22
During interphase of the cell cycle, individual chromosomes cannot be seen within the nucleus. The genetic material is termed chromatin during this stage. Changes occur to…
Answer this question and get it marked →October–November 2024, Paper 11
The photomicrograph shows a stage of mitosis in which the chromosomes appear as a condensed mass aligned at the centre of the cell (metaphase). What would be correct for the next…
Answer this question and get it marked →What are the correct roles of mitosis? Row stem cell growth replacing lost skin cells --- --- --- A correct not correct B correct correct C not correct not correct D not correct…
Answer this question and get it marked →Which row about the stages of the mitotic cell cycle is correct? Row DNA ligase used in the nucleus RNA polymerase used in the nucleus --- --- --- A G1 phase S phase B G2 phase…
Answer this question and get it marked →There are 64 chromosomes in the muscle cells of a particular mammal. How many DNA molecules are present in a cell during early prophase and telophase of mitosis? Row early…
Answer this question and get it marked →October–November 2024, Paper 12
Chickens have 78 chromosomes in the nucleus of a body cell. How many DNA molecules are there in a chicken body cell at the start of prophase of mitosis?
Answer this question and get it marked →The photomicrograph shows cells undergoing mitosis, with one cell labelled X. Cell X contains chromosomes that are condensed and aligned along the equator of the cell (metaphase).…
Answer this question and get it marked →Which processes occur in bone marrow cells that are in a mitotic cell cycle? 1 Phosphate groups bind to ADP molecules to form ATP. 2 Bonds form between nucleotides in a DNA…
Answer this question and get it marked →The enzyme telomerase prevents loss of telomeres after many mitotic cell cycles. Which cells need to transcribe telomerase enzyme? 1 stem cells; 2 activated memory B-lymphocytes;…
Answer this question and get it marked →October–November 2024, Paper 13
Which process does not involve mitosis?
Answer this question and get it marked →The photomicrograph shows cells in an onion root tip. Three cells are labelled X, Y and Z. Cell X shows chromosomes arranged as separated groups moving towards opposite poles;…
Answer this question and get it marked →The diagram shows an outline of the mitotic cell cycle drawn as a circle divided into stages numbered 1, 2 and 3, with cytokinesis labelled as a thin section. Stage 1 is…
Answer this question and get it marked →October–November 2024, Paper 21
Fig. 6.1 shows a plant cell in a stage of mitosis (a photomicrograph showing chromosomes separating towards opposite poles with a clearly visible spindle). Some of the structures…
Answer this question and get it marked →October–November 2024, Paper 22
Adult stem cells are undifferentiated cells that are found in most animal tissues. Adult stem cells can divide by mitosis throughout their lifespan to form identical stem cells…
Answer this question and get it marked →October–November 2024, Paper 23
Stem cells are found throughout the human body. Lgr5+ stem cells are found in the lining of the small intestine. Fig. 2.1 is a flow chart showing stages in the development of one…
Answer this question and get it marked →May–June 2023, Paper 11
The cell cycle includes mitosis. What are features of this type of nuclear division? 1 forms cells of equal size to the parent cell; 2 forms genetically identical nuclei; 3…
Answer this question and get it marked →A student observed the cells in the growing region (meristem) of an onion root and obtained the data shown. stage number of cells --- --- interphase 886 prophase 73 metaphase 16…
Answer this question and get it marked →May–June 2023, Paper 12
The diagram shows part of the organisation of a section of a DNA molecule and the associated histones, P and R, in prophase of mitosis, with the DNA labelled Q. Which statement…
Answer this question and get it marked →How many copies of each DNA molecule will be found in a cell at the start of the stages of the mitotic cell cycle shown? The options are given as a table for G1 of interphase and…
Answer this question and get it marked →May–June 2023, Paper 13
Which row describes some properties of stem cells? The options are given as a table with a tick for 'is a property' and a cross for 'is not a property' across able to divide by…
Answer this question and get it marked →The mitotic index is a measure of the proportion of cells that are undergoing mitosis in an area of tissue. It is calculated using the formula: mitotic index = (number of cells…
Answer this question and get it marked →May–June 2023, Paper 22
Fig. 2.1 is a photomicrograph of a longitudinal section (LS) through a root tip. Two different regions are visible: the root apical meristem and the root cap. Cells in the root…
Answer this question and get it marked →May–June 2023, Paper 23
The cells in a tissue are often at different stages of the cell cycle. Fig. 1.1 shows cells at different stages of the cell cycle. Four cells are labelled A, B, C and D, showing…
Answer this question and get it marked →October–November 2023, Paper 11
Which row is a representation of one chromosome at the beginning of prophase of mitosis and the number of DNA strands in the chromosome? Rows A and B show a chromosome made of two…
Answer this question and get it marked →Which events are part of mitosis? 1 interphase 2 telophase 3 cytokinesis A 1, 2 and 3 B 1 and 3 only C 2 and 3 only D 2 only
Answer this question and get it marked →The photomicrograph shows a cell during mitosis, with two groups of chromosomes being drawn towards opposite poles of the cell. What is happening in this cell? 1 Chromosomes are…
Answer this question and get it marked →October–November 2023, Paper 12
A human embryo consists of 12 cells at the start of day 1. The cells divide by mitosis for 4 complete days at a rate of 1 division every 32 hours. What is the maximum number of…
Answer this question and get it marked →Which diagrams show roles of mitosis? Diagram 1 shows a parent plant producing daughter plants via runners (asexual reproduction). Diagram 2 shows a flower developing into a…
Answer this question and get it marked →Which events are part of the mitotic cell cycle? 1 interphase 2 anaphase 3 cytokinesis A 1, 2 and 3 B 1 and 2 only C 1 and 3 only D 2 only
Answer this question and get it marked →October–November 2023, Paper 13
Which statement about the behaviour of chromosomes during telophase is correct? A Chromosomes attach to the spindle fibres at the equator. B Chromosomes start to uncoil inside the…
Answer this question and get it marked →The transmission electron micrograph shows a cell in a stage of the mitotic cell cycle. Which statement explains why it is difficult to identify the stage of the mitotic cell…
Answer this question and get it marked →October–November 2023, Paper 21
State the name of the phase of the mitotic cell cycle during which DNA replication occurs.
Answer this question and get it marked →October–November 2023, Paper 22
During interphase and mitosis of the cell cycle, the chromosomes within a cell go through a number of changes. Each chromosome is composed of DNA complexed with proteins. In…
Answer this question and get it marked →October–November 2023, Paper 42
Yeasts are unicellular organisms from the kingdom Fungi. Saccharomyces cerevisiae can carry out asexual reproduction by mitosis or sexual reproduction by meiosis, and exists as…
Answer this question and get it marked →Other AS & A Level Biology topics
- Biological molecules (115)
- Cell structure (98)
- Transport in plants (91)
- Transport in mammals (77)
- Cell membranes and transport (67)
- Nucleic acids and protein synthesis (63)
- Practical skills (61)
- Enzymes (59)
- Gas exchange (53)
- Infectious disease (49)
- Immunity (42)
- Inheritance (25)