Topic 4 - Natural Selection & Genetic Modification Flashcards
Describe the work of Darwin and Wallace in the development of the theory of evolution by natural selection
- While travelling independently, they notices there was variations in species in different areas
The Process of Natural Selection (Darwin’s Theory)
- Random mutations occur
- Compete to survive
- Survival of the fittest
- Survivors reproduce to pass on alleles
- Alleles are more common in population
Explain how antibiotic resistance in bacteria support Darwin’s theory
- Random mutations in bacteria occur
- Compete to survive
- Survival of the fittest
- The bacteria which survive divide to pass on alleles
- Alleles are more common in population, bacteria continue living
Ardi
- Had a small brain size
- Hands and feet adapted for both tree-climbing and bipedal walking.
- Lived 4.4 million years ago.
Lucy
- Walked upright
- Long arms and a small brain
- Lived 3.2 million years ago.
Leakey’s discovery of fossils
- Attributed to Homo habilis
- Larger brain size compared to earlier
- Evidence of early tool use.
Describe the evidence for human evolution based on stone tools
As time went on:
- they became more complex
- older were found further underground
- they had different carbon amounts
How does the pentadactyl limb provide evidence for evolution
- Although they have all evolved for different purposes, they all have the same basic layout
5 Kingdoms of Classification
- Prokaryotes
- Protists
- Fungi
- Plant
- Animal
3 Domains
- Archaea
- Eukaryota
- Bacteria
Impact on food plants and domesticated animals due to selective breeding
- Selection of desired traits
- Resistance to pests and diseases
- Improved quality
Selective breeding
- Select individuals with desirable characteristics and breed them together
Process of tissue culture
- Small pieces of organisms (‘tissues’) are grown (‘cultured’) using nutrient media (artificial growth medium)
Advantages of tissue culture
- Disease Elimination (in plants)
- Rapid Multiplication
Genetic Modification
- Modifying the genome of an organism to introduce desirable characteristics
Restriction enzymes in Genetic Modification
- Cuts the backbones of double bonds, separating the bonds themselves
Sticky ends in Genetic Modification
- The single-strand overhangs due to restriction enzymes
Ligase in Genetic Modification
- Sticks together the sticky ends and the genetically cut bacterium plasmid with same DNA code
Vectors in Genetic Modification
- Delivers foreign DNA into a host organism
Advantages of genetic engineering to produce GM organisms:
- Mass production
- Future visions like animal organs for human transplants
- Modify crops to suit environment
Disadvantages of genetic engineering to produce GM organisms:
- Difficult to predict effects
- Ethical concerns if used on humans
- Genes from GM organisms can get into environment
Advantages of the agricultural solution:
- Fertilisers
- Increased Crop Yields
- Resistance to disease
- Year-round production
Disadvantages of the agricultural solution:
- Fertilisers
- Environmental Pollution
- Soil Degradation
- Cost to Farmers
Advantages of the agricultural solution:
- Biological Control
- Reduced Pesticide Dependency
- Long-Term Sustainability
- Enhanced Biodiversity
Disadvantages of the agricultural solution:
- Biological Control
- Only sometimes gets desired result
- Time and Research Investment
- Risk of Non-Target Effects
Advantages of Selective breeding and Genetic Modification
- Agriculture benefits like higher yield
- Medicine
Disadvantages of Genetic Modification
- Transferring genes to wild population risk
- Ethical issues (modifying embryos)
Disadvantages of Selective Breeding
- Reduced Genetic Diversity
- Ethical issues (forced to breed, and compromise their wellbeing
