Learning
Question
How do environmental
factors influence our
identities?
Success Criteria
• State examples of ways that the environment can
influence our genes
• Describe how the environment affects how inherited
characteristics develop
• Describe how the organisms final appearance is a
result of the interaction of the genes and the
environment
What causes variation?
• Some variation within a
species is inherited, and
some variation is due to
the environment
What causes variation?
Examples of inherited variation:
• eye colour
• hair colour
• skin colour
• lobed or lobeless ears
What is Environmental variation?
Environmental variation
• Our genetic make-up, the sum total of our genes, is
called a genotype, but the characteristics which show
up in our appearance are called a phenotype
• An organism’s final appearance (phenotype) is a result
of the interaction between the information held in its
genotype and the effect of the environment acting on
it during growth and development which is shown in
the equation:
Genotype + Environment → Phenotype
What are the environmental factors
that affect our genes?
• Genetic variation gives rise to differences
between individuals that are inherited.
• For example, our eye colour is inherited from
our parents. But our phenotype is also
affected by environmental variation such as:
– climate
– diet
– physical accidents
– culture
– lifestyle
This is an oak tree. It is 20m tall. It has leaves that look like this:
In the summer the leaves are different shades of green. Some of its
leaves are brown because of a disease caused by fungi. The trunk has
a circumference of 2m. It has a large hole in it from a woodpecker.
The tree produces a fruit called acorns which look like this:
Inherited
Environmental
Possibly both
Its species (oak)
Its brown leaves
Its height
The shape of its
leaves
The hole in the
trunk
The circumference of
the trunk
The type of fruit
(acorns)
The colour of its
leaves
This is a cactus. It lives in Arizona in the USA. It is 3m tall and
1.5m across. It has a hollow stem which is full of water. It is covered
in spikes in order to stop animals eating it. Once a year it has white
flowers which look like this:
It has very long roots to get as much water as possible. It is a dark
green colour.
Inherited
Environmental
Possibly both
Its species (cactus)
The water in the
stem.
Its height
Its hollow stem.
Its width
Its spikes
Its colour
Colour and shape of
flowers
The length of its
roots.
http://www.neok12.com/video
/Genetics/zX5870617f4648
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What causes variation?
Name 3 examples of inherited variation.
Name 3 examples of environmental variation.
State characteristics that are influenced by our
genes and the environment.
5. Describe the difference between phenotype and
genotype?
6. Describe how our phenotype is influenced by our
genotype as well as our environment.