Genetic Engineering
Restriction enzyme is an enzyme designed to cut a useful gene out of an organisms DNA.
State two reasons for extinction
loss of food source
predation
disease
change in environmental conditions
inceased competition
Define a Fossil
The remains of organisms from millions of years ago which are found in rocks. Allows Scientits to discover evolution.
Define a mutation
Change in base sequence of DNA
State two examples of selection pressure
1. Competition for food/habitat (shelter / territory)/mates
2. Environmental conditions e.g.
Temperature, weather conditions or geographical access
3. Predators
4. pathogens (diseases)
5. Mating
State the last step of genetic engineering
Replace the plasmid in the bacterial cell and grow in a huge tank. The desired gene can then be extracted.
State the order of Carl Linnaeus classification system
Keep - Kingdom
Ponds - Phylum
Clean - Class
Or - Order
Frogs - Family
Get - Genus
Sick - Species
State the appearance of more recent tools
More recent tools are more sophisticated and complex, they were created a more of a narrow-edge.
Define classification
Organisms are grouped according to similarities and differences in their observable characteristics.
Define Variation
Variation caused by the different alleles inherited during sexual reproduction/due to mutations.
State one similarity and one difference between genetic engineering and selective breeding
Similarities
1. change characteristics of an organism
2. produce useful characteristics
Differences
1. Carried out differenct number of times
2. GE needs more specialist equipment
3. SB chance offspring dont have desired characteristic
Suggest how Scientists classified organisms into the three domains
Scientists used 'genetic analysis'
This identifies differences in DNA for all types of organisms in kingdoms.
More DNA two organisms have in common
More recently they evolved from a common ancestor More closely related
Scientists can look at DNA, amino acids and DNA sequences across organisms and compare how similar they are
State two ways early tools were used
Skinning or cutting up meat.
Creating fires
Constructing shelter
What is a binomial name
A binomial name is a two latin words for
naming a species. Genus and Species.
Explain how a farmer could produce a yield of cotton candy grapes.
1. Decide which characteristics are important
2. Choose parents that show these characteristics
3. Select the best offspring from parents to breed the next generation
4. Repeat the process continuously
State an advantage and disadvantage of genetic engineering
Advantages
- GOLDEN RICE is a type of GM rice that has a higher Vitamin A ?
- To solve the Global food security crisis
- GM crops to produce a bacterial toxin that will kill insects that eat.Less pesticide is needed and less crop is lot to the pests.
- Insulin is produced on a large scale where no animals are used or harmed.
Disadvantages
- The is no understanding of the long term effects GM food products will have on human health
- GM crops are very expensive to produce - unaffordable to farmers and communities in poorer countries.
- Toxins can kill other harmless and beneficial insects like bees and butterflies. Cross pollination - gene may spread to weeds which will compete with the crop. Insects may become resistant to the toxin due to natural selection.
Early humans were described as being bipedal. Using your knowledge of selection pressures, suggest why this might have been beneficial for early humans.
- This would have allowed early humans to be taller so they can identify food and predators.
- Allows their hands to be free to be used for hunting.
State two pieces of evidence for human evolution
Humans became taller
The size of their skulls increased
State the 5 kingdoms and a characteristic of each
Animalia
Plantae
Fungi
Protist
Prokaryote
State three uses of selective breeding
- Production of disease resistant crops (how well they cope with diseases)
- Yield (how much useful product they make)
- Coping with certain environmental conditions
- Fast growth
- Flavour
Suggest how genetic engineering can be used to produce plants resistant to herbicide.
1. A restriction enzyme is used to cut a useful gene out of an organism's DNA. When restriction enzymes are used to make cuts in the DNA, it produces DNA with sticky ends.
2. Restriction enzymes are also used to cut plasmids open. By using the same restriction enzyme as on the DNA, the DNA and plasmid will have the same sticky ends.
3. Sections of DNA from the organism and the cut plasmids are mixed. The complementary bases on the sticky ends pair up. An enzyme called ligase is used to join the sticky ends together. The new DNA is known as recombinant DNA.
4. The plasmids are then inserted back into the bacteria, which are then grown in a huge tank. The desired gene can then be extracted.
State which two domains were the most closely related and characteristics to explain this
Archaea and Eukarya are closely related as they have many similar characteristics.
Similarities:
Unused sections of DNA
Absence of a peptidoglycan cell wall and ribosomes which are sensitive to drugs.
Differences:
Archaea don’t contain a nucleus and eukarya do
State the structure of the pentadactyl limb
- Five digits (carpal bones)
- Ulna & radius bones
- Humerus bone
Explain how organisms can evolve by natural selection
Natural selection describes how ...beneficial.......................... alleles ?become more common in a population.
There is variation due to mutations/sexual reproduction.
Selection pressures such as .....predation....................... ?mean that not all organisms will .....survive.................... and reproduce.
Individuals with alleles that make them better ......adapted to................... ?their environment are more likely to survive and pass on their ?alleles to their .......offspring............................
State and explain issues with selective breeding
1. Gene pool in a population will decrease overtime
2. Many genetically similar organisms.
3. Mutation in the population of selectively bred organisms, then it is more likely organisms will inherit the mutation ( due to reduced gene pool)
4. All organisms will be equally susceptible to a specific disease.