Variation Flashcards
What does variation mean?
Differences between organisms
What does genetic variation mean?
Differences caused by the genes we inherit
What does environmental variation mean?
Differences caused y the environment we live in
What is meant by the ‘characteristics’ of organisms?
Their features e.g. eye colour, height etc.
Name the 2 types of variation
Genetic variation
Environmental variation
An organisms characteristics are controlled by its…
genes
An organisms genes are _______ from its parents
inherited
Why does an organism look like both parents?
Because the genes of both parents mix during fertilisation.
What is fertilisation?
When a sperm enters an egg
What is the scientific name for eggs and sperm?
Gametes
Why are brothers and sisters not identical?
Because they receive a different mix of genes from their parents
Which human characteristics are controlled only by genes?
Natural hair colour
Natural eye colour
Blood Group
How can a persons weight be affect by genes AND the environment?
Access to more or less food in their environment
Weight is inherited from parents genes.
How can a persons nose shape be affected by genes AND the environment?
May break nose due to environment
Surgery
Nose shape is inherited from parents genes.
How can the height of a plant be controlled by genes AND the environment?
Plant height genes are inherited from parents.
Access to sunlight or nutrients in the environment.
Who are the only people who have no genetic variation at all?
Identical twins
Why do identical twins show no variation at all?
They come from the same egg and sperm cell
They inherit identical genes
