Variation refers to the differences in characteristics among individuals of the same species. It is evident in human populations through features such as height, body mass, skin colour, blood groups, and fingerprints.
A side-by-side view of the bell-shaped curve and discrete bars, with their contrasting features.
Variation is the differences in characteristics among individuals from the same species.
Variation is broadly categorised into two types: continuous variation and discontinuous variation.
Shows differences that are not distinct or not clear between individuals in the same population. It is quantitative, can be measured, and is represented by a normal distribution curve. Examples include height, body mass and skin colour.
Shows differences that are distinct or very clear between individuals of the same population. It is qualitative, falls into distinct categories, and is represented by a bar chart with discrete shapes. Examples include ABO blood groups, tongue rolling ability, fingerprints and earlobes.
Crossing over between homologous chromosomes during meiosis, independent assortment of chromosomes, random fertilisation between male and female gametes, and chromosome and gene mutations.
pH, sunlight, temperature, water, climate and nutrition. For example, a person often exposed to sunlight will have dark skin colour, and the Hydrangea sp. flower is blue in acidic soil but pink in alkaline or neutral soil.
Variation enables organisms to adapt and survive environmental changes, allows natural selection and evolution, helps organisms camouflage from predators, enables individual identification, and increases the commercial value of animals and plants through genetic engineering and selective breeding.
Answer in your mind, then press “Check Answer”.
What is the main difference between continuous variation and discontinuous variation in terms of the factors controlling them?
State two genetic factors during sexual reproduction that contribute to variation in offspring.
How does environmental factor affect the colour of Hydrangea sp. flowers?
All variations are inherited by the next generation.
Only variations caused by genetic factors can be inherited. Phenotypic variations caused solely by environmental influences, such as getting a suntan or gaining weight due to overeating, cannot be passed down to offspring.
Continuous variation traits have fixed separate categories.
Continuous variation features a continuous spectrum of values with intermediate forms, such as height ranges, which cannot be divided into isolated categories.
Discontinuous variation is influenced by both genes and environment.
Discontinuous variation is determined strictly by genetic factors only and is entirely unaffected by environmental factors.
1 Which of the following characteristics represents continuous variation in humans?
2 What type of graph is used to represent discontinuous variation?
3 Crossing over between homologous chromosomes during allows the exchange of genetic materials to produce new genetic combinations.
4 The flower of Hydrangea sp. turns blue when planted in soil.
Drag each item to the correct category. On a phone, tap an answer first, then tap a matching box. Tap the Answer Choices area to return a selected item.
Write the correct item next to each category.
Answer choices: Ability to roll the tongue • Human body height • Crossing over during meiosis • Soil pH affecting flower colour
There is something wrong with this question.
