Natural Selection Flashcards
What are the 7 steps of natural selection?
- Variation caused by mutation
- Competition/camouflage
- Best adapted
- Survive
- Breed
- Pass on alleles
- Natural selection
How do tools help to date fossils?
They got more sophisticated over time so the deeper in the rock, the older they are
What are the 5 classification kingdoms?
Fungi Plants Animals Prokaryotes Protoctists
What give an organism its binomial name?
‘Genus’ and ‘species’
What are the 3 domains?
Eukarya
Bacteria
Archaea
What is eukarya?
Nucleus with some unused dna present
What is bacteria?
No nucleus with all dna used for something
What is archaea?
No nucleus with some unused dna present
What is evolution?
A gradual change in the characteristics of a species over time
Which fossil was found 1.6 million years old?
Homo erectus/Richard Leakey
Which fossil was found 3.2 million years old?
A. Afarensis/Lucy
Which fossil was found 4.4 million years old?
A. Ramidius/ardi
What is selective breeding?
The process of choosing desirable characteristics from an organism and breeding them with another organism with the same characteristics to produce offspring with the desired traits
A farmer wants large cows. Explain how he would do this
- Choose 2 biggest cows from existing stock
- Breed together
- Pick largest offspring from different parents and breed them
- Repeat
Why selectively breed animals?
Higher yield of milk/meat/wool
Better quality of milk/meat/wool
Why selectively breed plants?
Disease resistance
Increased yield
Fast growth
What are the risks of selective breeding?
Gene pool reduces
Similar dna so if one is susceptible to disease then they all are
Sometimes cause characteristics which harm animals
What is genetic engineering?
Modifying the genome of an organism to produce desirable characteristics
What does modifying the genome mean?
Changing the dna/taking it from one organism and putting it into another
What are the steps of genetic engineering?
- Identify the target gene in the chromosome
- Cut out target gene using restriction enzymes
- When gene is cut out, sticky ends are left
- Take plasmid out of bacteria (vector)
- Cut open plasmid and stick target gene in
- Use ligase to secure the plasmid
- Place plasmid back into bacteria
How is genetic engineering useful in medicine?
You can produce bacteria which makes insulin
How do you make herbicide resistant plants?
- Identify herbicide resistant gene
- Cut out using restriction enzymes, leaving sticky ends
- Use ligase to stick gene and plant dna together
- Plant is herbicide resistant
What are the advantages of herbicide resistant plants?
Farmer can spray 1 large dose of herbicide which will kill the weeds but not the plants
Gives higher crop yield
What are the disadvantages of herbicide resistant plants?
Crops and weeds could cross breed and weeds would become resistant
Loss of biodiversity
Unknown if eating gm food could harm people
How do you make insecticide producing plants?
- Identify insecticide producing gene
- Cut out using restriction enzymes which leaves sticky ends
- Use ligase to stick gene and plant dna together
- Plant produces insecticide
What are the advantages of insecticide producing plants?
Farmer doesn’t need to spray insecticide - saves money
Plants won’t be eaten by insects - higher crop yield
What are the disadvantages of insecticide producing plants?
Crops and weeds could cross breed and weeds would kill insects
Loss of biodiversity
Unknown if gm food could harm people
