FreeScienceLessons · AQA BiologyVariation — genetic and environmental
Key facts
Types of variation — fill in the table
Term
Detail
Continuous variation
Discontinuous variation
Continuous variation graph
Discontinuous variation graph
Causes of variation — fill in the table
Term
Detail
Genetic variation
Environmental variation
Genetic and environmental
Mutations
Exam questions — 3 questions · 9 marks
⚡ Extended questions included. Read the hint. Write in full sentences. AI marks against the AQA mark scheme.
1 markContinuous variationAQA 8461 style
Which of the following is an example of continuous variation?
A Blood group
B Ability to roll tongue
C Height
D Sex
1 markMutation causeAQA 8461 style
What causes a genetic mutation?
A Environmental factors only — mutations are always caused by radiation or chemicals
B A random change in the DNA base sequence
C Crossing over of chromosomes during mitosis
D Inheritance of alleles from parents
4 marksExplain why variation is important for evolutionAQA 8461 P2 style
Explain why variation within a species is necessary for evolution by natural selection to occur. (4 marks)
Hint: Cover: variation exists → some traits are better adapted → those individuals survive and reproduce → pass on alleles → frequency increases over generations.