1. AS Biology Variation Lesson One
Course: AQA AS Biology Unit 2 Variety of Living Organisms Duration: 1 hour 30
Aims: investigating what variation is and how it is measured Previous Knowledge: GCSE science/biology
Learning Objectives
All students will know: Most students will know: Some students will:
that variation exists between members of the that genotype refers to the genetic traits and consider some intraspecific traits of people that
same species and this is intraspecific variation phenotype refers to physical traits could be investigated for variation and the
interspecific variation is variation that occurs the difference between continuous and possible causes for them
between different species discontinuous variation
environmental and genetic factors contribute to what normal distribution looks like
causing variation
Timing Content/Skills Development Teaching and Learning Activities
Settler 5 - 10 Thunk: Thinking skills - what is variation why is it that even though people are all of the same species, we all
look so very different?
introduce the idea of intraspecific variation
Starter 15-20 building up glossary of key terms, definition: what is variation pair-group-class definition
compare to ʻtextbook answerʼ
develop student glossary with the terms intraspecific and interspecific
(analogy to internet/intranet)
know-want-learn grid
brainstorm with students what they already know and want to learn,
revisit this at the end of the chapter before the end of chapter test

2. AS Biology Variation Lesson One
Timing Content/Skills Development Teaching and Learning Activities
Main 45 What causes variation? introducing the terms causes of variation
genotype and phenotype present: terms phenotype and genotype, idea that some traits are
environmental and some are genetic. Give example of genetic and
if time permits continuous and discontinuous example of environmental
data and normal distribution action: students to sort through some examples and place them onto
venn diagrams (A3 - A5 for individuals)
how confident can we be in saying one thing review: volunteer student to go through answers on visualiser, class
causes the variation? discussion and justification
continuous and discontinuous data - A/B/AB/O blood groups vs.
height, how could we present this data in a graph, one is continuous
and one is discontinuous - which is which? can we summarise this in a
diagram?
confidence in the causes of variation
present: give students the idea that height is not just genetic, example
of on average a mean lower height in some nations related to diet
(compare two graphs)
action: Give students another example of variation (hair colour?) and
ask what is the cause of this. Is it genetic or environmental? How
confident are they that this is the case? place these onto a confidence
scale on the board (also on the back of their venn diagrams)
review: Why can we not always be confident that there is just one
cause to variation? how would we answer this question in an
examination?

3. AS Biology Variation Lesson One
Timing Content/Skills Development Teaching and Learning Activities
Plenary 15-20 Plenary making notes no homework set for
students to make notes under a number of this lesson
headings
1. what is variation
2. what causes variation
3. how confident we can be about the causes
of variation
Question for Thursdays lessons thunk: When
studying variation, often twins are used. Why?
Extension For those who progress more quickly is your hair colour genetic? environmental or both? why? argument
map of hair colour variation
What is the hair colour variety in the classroom? how could you
choose a random sample of students from the AS biology students?