B15 Flashcards
Archaea
Organisms that are unicellular, like bacteria, but biochemically very different to bacteria; often live in extreme environments, like in very hot water around geysers.
Biochemistry
Chemistry dealing with chemical compounds and processes in living plants and animals.
Classification
The process of grouping things based on their similarities.
Eukaryota
Organisms that contain nuclei, includes animals, plants, fungi, and protists.
Evolutionary tree
A diagram that reflects evolutionary relationships among groups of organisms.
Extinction
When all members of a species have died.
Fossil
A trace of an ancient organism that has been preserved in rock.
How are fossils formed?
When plants and animals die and are quickly buried by clay, sand and other sediments. Traces of organisms are preserved, covered in sediment and become rock.
How did Mendel study inheritance?
Through carry breeding experiments on plants and analysing the ratio of characteristics in offspring.
How do fossils act as evidence for evolution?
Scientists can identify the ages of the fossils and use them to show how organisms change over time.
Resistant strain
Resistant cells that reproduce and eventually replace the whole population.
State the factors that may lead to extinctions.
- new disease
- predators
- competition
- changes to enviroment
- catastrophic events
State two kinds of evidence used to show evolution
Fossils and antibiotic resistance in bacteria
What do branches in evolutionary trees indicate?
Where speciation has occurred.
What enables bacteria to evolve quickly?
The fast rate of their reproduction.
What is speciation?
The formation of a new species when two populations become so varied that they cannot interbreed to produce fertile offspring
What is the definition of a species?
A group of organisms with similar characteristics which are able to interbreed to produce fertile offspring
Why are resistant strains of bacteria dangerous?
People have no immunity to them and there is no effective treatment.
Why is it difficult to keep up with emerging resistance strains?
Developing antibiotics have a high cost and take a long time to develop.
Why was Darwin’s theory of evolution not accepted immediately?
- most people believed in creationism
- insufficent evidence to prove the theory
Who developed the ‘three-domain system’ of classification?
- Carl woese
Give one disadvantage and one advantage of mass extinction events.
Answer in terms of evolution.
Dis = Reduction in a range of alleles
Ad = Allowes evolution of new species
