Genetic and environmental variation

Overview

The genetic and environmental factors behind a phenotype, etiolation as a worked example, and the meiosis and random fertilisation that generate variation.

What you need to know

Answer each one before you reveal it.

Questions from this subtopic

Each one with the model answer underneath.

1. 1

   What two broad categories of factors combine to produce phenotypic variation in organisms?

   Model answer

   Genetic factors and environmental factors.

2. 2

   How do genetic factors contribute to phenotypic variation?

   Model answer

   Different alleles and combinations of alleles inherited from parents produce different phenotypes.

3. 3

   How do environmental factors contribute to phenotypic variation?

   Model answer

   External conditions such as temperature, light, and nutrient availability can modify how genes are expressed, altering the phenotype.

4. 4

   Give an example of an environmental factor that contributes to phenotypic variation in animals.

   Model answer

   Diet.

5. 5

   How can diet affect phenotypic variation in animals?

   Model answer

   Nutrient availability influences growth, body mass, coat condition, and other physical characteristics.

6. 6

   What is etiolation in plants?

   Model answer

   Etiolation is the elongated, pale growth of plants that occurs when they are grown in the absence of light.

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The same content, four other ways.

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