Evolution, classification + genetic modification- SB4 Flashcards
what is the binomial naming system?
each organism is named for its genus then its species. system of naming species uses Latin words. Each name has two parts, the genus and the species
what is the binomial system?
a process of putting 2 latin words are put together to name a species
what is evolution?
gradual change in the characteristics of a species over time
what is genetic variation?
variation of the characteristics of individulas
what is environmental change?
conditions in an area changing
what is natural selection?
the variations of some individualorganisms make them better at coping with change than others and hence are more likely to survive
what is inheritence?
the survivors breed and pass on their variations to new generations and so the next gen contains more individuals with the ‘better-adapted’ variations
what is an example of hyper-evolution?
when a rat poison was first used in the 1940s, most rats died - within 10 years most rats had become resistant to it. By killing off all the rats who were not resistant, only the resistant ones were left to breed and hence brought up new generations of resistant rats- they had to evolve quickly to survive and void extintion
how are animals classified?
in order
largest group- kingdom
smallest groups - genus and species
what are the 5 types of kingdom?
animals, plants, fungi, protists, prokaryotes
what are the main characteristics of prokaryotes?
unicellular, cells do not have nuclei, flexible cell walls
what are the main characteristics of protists
mostly unicellular, cells have nuclei, some have cell walls
what are the main characteristics of fungi?
multicellular, live in or on dead matter on which they feed, cells have nuclei, cell walls contain chitin
what are the main characteristics of plants?
multicellular, have choloroplasts for photosynthesis, cells have nuclei, cellulose cell walls
what are the main characteristics of animals
multicellular, cells have nuclei and no cell walls
What are the 3 domains that Carl Woese proposed? and what are their main characteristics?
Archaea - cells with no nucleus, genes contain unused DNA
Bacteria - cells with no nucleus, no unused sections in genes
Eukarya - cells with a nucleus, unused sections in genes
what is artificial selection?
when humans choose certain organisms because they have useful characteristics
what is selective breeding?
Picking off-spring with ceratin characteristics they want to enhance and reproducing them
What are plants and animals often selectively bred for?
disease resistance, yield of useful product, coping with ceratin environmental conditions, fast growth and flavour
what is genetic engeneering?
involves changning the DNA of an organism by inserting genes from another to create genetically modified organisisms
What is genetic engineering good for?
adding vitamins into crops
adding proteins into animals
What are the risks of selective breeding?
- some alleles not selected may disappear and so any that could have been useful in the future arent availible
- When farming large numbers of the same breed - all the organisms are similar, so one affected by disease means the rest will be.
- animal wellfare may suffer as selective breeding may do more harm to the creature
what are some issues with genetic engineering
- seeds for GM plants are expensive
- GM plants reproducing with wild varieties may cause issues
- some think eatin GM organisms are bad for health
what can GM bacteria be used to produce? - why is using GM a better alternative to the current situation?
inslulin - used to be extracted from dead animals but GM bacteria is cheaper and suitable for more people.
how is bacteria genetically engineered?
bacteria has one loop of DNA conatining smaller circles called plasmids - additional genes are added to the plasmid to become recombinant DNA
What is Bt toxin?
natural insceticide made of soil bacterium
What are issues with crops that use Bt toxin?
- Pests that do not chew plant tissue remain unharmed
- insect can develop resistance
what is biological control?
using predatory insects to remove pests to help increae crop yield
What is in fertilizers that helps plants grow?
mineral salt ions such a nitrgoen, potassium and phosphorus
what is the issue with fertilizer?
if the plant does not absorb all of it, it amy transfer into a river and cause pollution - leading to the death of organisms in the water and those that drink it
