Evolution & Genetic Modification 🧿 Flashcards
What is evolution
The gradual change in the characteristics of a species over time
State the definition of a fossil
The remains of an organism from thousands or millions of years ago which are found in rocks
Name two ways in which remains of dead animals and plants can be preserved
In tree sap (hardened clear material called amber)
In ice

How can the fossils rise from deep in the earths crust
(Tectonic movement)
Earthquakes
Formation of mountains
What was Dawin’s theory
Organisms that are best for adapted for their environment will reproduce and pass on the AQUIRED CHARACTERISTICS
Name four key points about natural selection
Individuals within a species show variation
Individuals within a species compete for resources
Only the individual best adapted to the environment will survive
Only the survivors will pass on their genes
What is classification?
The grouping of organisms based on similarities of features
What is artificial classification?
Based on observable features e.g. beak shape, flower colour, number of legs
What is natural classification
Based on evolutionary links i.e. do they have a common ancestor?
Name the five kingdoms
Animals
Plants
Fungi
Protists
Prokaryotes
What are the three domains created by Carl Woose in 1990
Bacteria
Archaea
Eukarya
What is one unit of classification known as
Taxon
List each unit of classification
Kingdom
Phylum
Class
Order
Family
Genus (italics)
species (italics)
What is a species
A group of similar organisms able to reproduce and produce FERTILE OFFSPRING
Who invented classification systems
Carl Linnaeus 250 years ago
What are the main characteristics of the kingdom of animals
Eukaryotic
multi cellular
no cell walls
must eat other organisms to obtain energy
What are the main characteristics of the plants kingdom
Eukaryotic
multi cellular
makes its own food
cellulose cell walls
What are the main characteristics of the kingdom of fungi
Eukaryotic
multi cellular
live in dead organic matter which they feed on to obtain energy
chitin cell walls
What are the main characteristics of the Protists kingdom
Eukaryotic
mostly unicellular
some have cell walls
What are the main characteristics of the prokaryotes kingdom
Unicellular
prokaryotic
flexible cell walls
no membrane-bound organelles eg. mitochondria & nucleus
What is artificial selection
When humans choose certain organisms because they have useful characteristics
What is selective breeding
Breeding the animals with the desired feature together to ensure offspring have the desired feature
What is genetic engineering
Involves changing the DNA of one organism (it’s GENOME) often by inserting genes from another.
This creates genetically modified organisms
What is golden rice
It is a GMO
2 genes are inserted into its genome (1 from a daffodil, 1 from a bacterium)
Allow rice to produce betacarotene which allows humans to produce vitamin A which helps prevent blindness
What are the benefits of genetically modified organisms (GMOs)
Can make organisms resistant to disease
GM sheep and goats that produce protein in their milk to treat diseases
GM bacteria to make medicine and antibiotics
GM pigs are being developed of human like organs for transplants
What are some issues of genetic engineering
Seeds for GM crops are expensive
potential reproduction with wild plant varieties-can pass on resistant genes which may have unknown consequences
health issues eating GM crops
What is a plasmid
A plasmid is a double-stranded loop of DNA typically found in bacteria
How do we genetically engineer bacteria
- Restriction enzymes make staggered cuts in DNA molecules producing sections with a few unpaired bases at each end (STICKY ENDS) 
- Restriction enzymes also cut plasmids open. By using the same restriction enzyme as was used on the human chromosome the cut plasmids have the same sticky ends
- A COMPLEMENTARY BASES on the sticky ends pair up and an enzyme called LIGASE is used to join the ends together
- The plasmids are then inserted back into the bacteria which are then grown in huge tanks. The insulin they now make can easily be extracted
What is a vector
Any DNA molecule used to carry new dna into another cell
How can insect pests be controlled
Insecticides
What is an alternative to pesticides
Biological control
What is biological control
Use of organisms to control pests
List advantages of GM crops
Only affects insects that eat the plant
Many different strains of Bt which produce slightly different forms of the toxin
Farmers make more profit grow in GM varieties
No evidence for health issues
List some disadvantages of GM crops
Some insect pests suck sap from the plant and don’t chew it so don’t eat the toxin 
Insects may develop resistance to the toxin so additional insecticides may be needed
GM crops seeds are more expensive than normal seeds
Rumours is associated with health issues
What are some of the issues with fertilisers
If not all fertiliser is absorbed by the crop it can get into nearby rivers and lakes which causes pollution and leads to death of organisms living in the water
It can also cause health problems for humans and animals that drink the water
What are fertilisers?
Contains mineral irons such as nitrogen, potassium and phosphorus.
Plants absorb through these from the soil once the fertiliser has been added to make healthy new cells
Describe evidence for human evolution
Stone tools: began with simple hand axes, now arrowheads
Many vertebrates including humans have the pentadactyl limb- suggest we have a common ancestor
Ardi & Lucy: female human-like fossilised skeleton dating from 4.4 million years ago (Ardi) and 3.2 million years ago (Lucy)
Ardi’s feet suggest humans and chimpanzees have evolved separately
Lucy’s bones suggest that she walked in an upright position like a human but possessed a relatively small ape-like skull
How has DNA analysis helped the process of classification
Classification was originally based on the way different species looked…
DNA analysis involves mapping the gene names of organisms…
This is the sequence of DNA base pairs that make up an organism…
comparisons between genomes of organisms in different species lets scientists see how close they are genetically…
which is a more accurate way of classifying organisms than the way they look
Name an example of biological control
A farmer releasing chickens into the crop so they can eat the caterpillars
What is a clone
A genetically identical copy of an organism
