Download LO * Explain how alleles cause differences in

LO – Explain how alleles cause
differences in inherited characteristics
• All – explain what inherited variation is
• Most – describe the structure of the nucleus
of a cell to include chromosomes and genes
• Some - use the key word allele to show how
genes can give rise to different inherited
characteristics
So what is inheritance?
1. What kind of things can be inherited?
2. How does this cause variation?
3. What is continuous variation? Give an example
4. What is discontinuous variation? Give an example
5. What is the difference between environmental and
genetic variation? Can you give examples?
So what is inheritance?
1. What kind of things can be inherited?
Eye colour, skin colour etc
2. How does this cause variation?
We get half our genes from each of our parents
3. What is continuous variation? Give an example
things like height – continuous scale
4. What is discontinuous variation? Give an example
things like eye colour – categories (brown/blue)
5. What is the difference between environmental and
genetic variation? Can you give examples?
Environmental – things you’re not born with
Genetic – things you are born with
How many people got 5 out of 5?
• How does this lead to inheritance? We inherit
traits from our parents as we get our genes
from them
The structure of the nucleus
• Nucleus –
• Chromosome –
• Gene –
• DNA
• Cell –
• Mitochondria -
The structure of the nucleus
• Nucleus – membrane enclosed part of the cell
which contains the genetic material
• Chromosome – a coiled piece of DNA which
stores the genes
• Gene – a section of DNA which codes for a
specific feature
• DNA – contains all the genes for an organism –
like blueprints
• Cell – building blocks of life
• Mitochondria – organelles of a cell which provide
energy for the cell
This looks like…
What’s an allele?
• Genes come in alternative forms
• This means that there is not just one ‘type’ of
gene for something
• For example there are many genes for height
• So you don’t get a ‘tall’ or ‘short’ gene but lots of
different ones together to help control how tall
you will be
• Or the genes for eye colour can be different
causing variation in the eye colour trait inherited
Lets use an analogy
• A car factory
Have we met the success criteria?
• All – explain what inherited variation is
• Most – describe the structure of the nucleus
of a cell to include chromosomes and genes
• Some - use the key word allele to show how
genes can give rise to different inherited
characteristics