Lesson T4.2.2

T4.2.2 Continuous and discontinuous variation Quiz: KS3 Biology, Unit 4

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson T4.2.2, Continuous and discontinuous variation: 20 multiple choice questions for the KS3 Biology (National Curriculum), Unit 4: Genetics and evolution, written with Revision Ninja.

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The 20 questions

  1. What is continuous variation?

    • Characteristics that depend only on the environment and not on genes
    • Characteristics that never change during the whole life of an organism
    • Characteristics that vary across a range of values with no distinct categories
    • Characteristics that fall into separate groups only, such as blood group

  2. What is discontinuous variation?

    • Characteristics that vary across a continuous range of measurable values
    • Characteristics that fall into distinct categories with no intermediate values
    • Characteristics that can never be inherited by the next generation of organisms
    • Characteristics that are always caused by the amount of light received

  3. How is continuous variation usually shown on a graph?

    • As a line that never changes direction across the whole range
    • As a pie chart with separate slices for each individual measured
    • As a bell-shaped curve or a histogram with no gaps between bars
    • As a single bar for each individual measured in the sample

  4. How is discontinuous variation usually shown on a graph?

    • As a single straight line drawn through the origin of the graph
    • As a histogram with no gaps between bars, showing a smooth range
    • As a map of the surrounding land showing where each group lives
    • As a bar chart with separate bars for each category

  5. A student measures the mass of 50 pupils and plots a histogram. What shape is most likely?

    • A single bar for every pupil measured in the class, each one separate
    • A bell-shaped distribution with most values near the middle
    • Each bar is the same height, showing no clustering at the average
    • A straight line with no spread, meaning every pupil has the same mass

  6. Why does height show continuous variation?

    • It can take any value in a range, such as 150 cm, 151 cm or 151.5 cm
    • It depends only on the colour of the eyes and the hair of a person
    • It can only be one of two values, tall or short, with nothing between
    • It is always exactly the same in one species, so it never varies at all

  7. Why does blood group show discontinuous variation?

    • Blood group changes gradually over a person's life as they grow older
    • Blood group depends on height, so taller people have different groups
    • Blood group has no genetic basis and is decided only by diet and habit
    • Each blood group is a distinct category with no in-between values

  8. Which factor is most likely to influence continuous variation like height?

    • Only the colour of the cell membrane
    • Only the amount of rainfall
    • Both genes and the environment, such as diet
    • Only the number of chromosomes

  9. Why do some characteristics show discontinuous variation mainly because of genes?

    • Single genes often produce distinct versions of a characteristic
    • Environmental factors always make them vary gradually
    • They depend only on sunlight
    • They are random and not inherited

  10. A histogram shows mass of plants with bars touching. What does this indicate?

    • The data is discontinuous
    • The data is about species
    • The data is continuous
    • The data is not measured

  11. A bar chart with gaps between bars shows what type of data?

    • Continuous data
    • Random noise only
    • Discontinuous data
    • Data from a single individual only

  12. Why must a graph of continuous variation be drawn carefully?

    • The values should be ignored and a single summary word written instead
    • Only one value should be shown on the graph, the average of the sample
    • Gaps should separate each individual's data point from the others
    • Bars or points should show the full range of values without gaps

  13. Which pair shows one continuous and one discontinuous characteristic?

    • Height and height
    • Blood group and blood group
    • Mass and mass
    • Mass and blood group

  14. Why is measuring continuous variation useful in a science investigation?

    • It shows the name of each species
    • It identifies the blood group of every individual
    • It prevents any variation being seen
    • It allows the spread and average of the data to be compared

  15. Which characteristic might vary continuously in a population of plants?

    • Stem length
    • Presence of a single flower type
    • A single leaf colour in every plant
    • Species name

  16. What is the best description of discontinuous variation's effect on a graph?

    • It produces a single straight line
    • It produces a smooth curve with no peaks
    • It produces separate peaks or bars
    • It produces no visible pattern at all

  17. Why is it important to take a large sample when studying variation?

    • A large sample makes all variation disappear from the population measured
    • A larger sample gives a more reliable picture of the population's variation
    • A large sample proves the species is extinct in the surrounding area
    • A large sample changes the genes of the population being studied

  18. Why do height differences in a population form a bell-shaped pattern?

    • Each person has only one height possible, set at birth and never changed
    • Height is controlled by a single gene with two versions, dominant and recessive
    • Height is determined only by the amount of sunlight the person receives daily
    • Many genes and environmental factors combine, so most values cluster near the average

  19. Which of these shows continuous variation in a population of sunflowers?

    • The species name of the plant
    • The height of each sunflower
    • Whether the flower is yellow or white
    • Whether the stem has leaves or not

  20. Which of these shows discontinuous variation in humans?

    • Body mass measured in kilograms
    • Whether a person can roll their tongue
    • Hand span measured in centimetres
    • Reaction time measured in milliseconds

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