Variation and Evolution Flashcards
Give some traits that result purely from genetics
Eye colour
Hair colour
Hight
Blood group
Give some traits that come form environmental factors
Accents
Skin colour
Behaviours
Name all 4 bases in DNA
Adenine
Guanine
Cytosine
Thymine
What is a mutation
A random change in DNA
Give an example of a positive mutation
Change in fur colour (Snow Leopard)
What is a neutral mutation
Mutation that doesn’t change the amino acid
Give an example of a negative mutation
Cancer, Cystic Fibrosis
How does one changed base mean a mutation
One changed base means a different codon which will code for a different amino acid and change the protein.
What is Sickle Cell Amnesia
Condition where there aren’t enough healthy red blood cells to carry oxygen around the body.
What causes chemical mutations
Nitrous acid
What causes ionising radiation
X-rays
Gamma-rays
What is evolution
The characteristics of a species change over time, evolved from the process of natural selection.
What did the study of Finches lead to
Theory of Evolution
What was the name of the ship Darwin sailed on
HMS Beagle
What is the name Darwin’s book
Origin of Species
Explain natural selection
Organisms produce more offspring than the environment can support
But the population remains stable
Populations will have variations
Some will be better competitors
These are the ones that will survive
Give the model answer that should be used for any natural selection question (9)
Variation exists in population (name trait)
This could be down to a random mutation
Competition
Some will have a better chance at survival (explain why)
Others die out
Survivors breed
Pass on genes
Trait is expressed in next generation
Repeated over many generations
All……….die out when they meet penicillin
Bacteria
How did bacteria become resistant to antibiotics
A normal bacteria cell mutated so that it was resistant to antibiotics
When treated with antibiotics the resistant one survived
When it reproduced it passes on genes for resistance. This is natural selection
