Biology- Evolution and Classification ( Topic 3 - Year 9)

genetic variation

different characteristics within a population due to differences in genes caused by random mutations and sexual reproduction

environmental variation

Different characteristics caused by an organisms environment

why is there usually extensive genetic variation within a population of species?

due to mutations

Charles Darwin

studied variation on a 5 year voyage around the world in the 19th century, he visited 4 continents in H.M.S Beagle

Wallace and Darwin

produced scientific journals together in 1858

• provided a foundation for understanding species diversity, adaptation and genetics

selection pressure

when the environment changes and some individuals are better adapted to others

survival advantage

individuals that are better adapted to the environment and more likely to survive and reproduce

inheritance

the survivors pass on their alleles to their offspring

evolution

change in a population's inherited traits over generations, driven by natural selection

fossils

preserved remains of a dead organism

how are fossils evidence for evolution

Fossils of the simplest organisms are found in the oldest rocks. More complex organisms are found in the newest rocks.

Pentadactyl limb

vertabrates have a similar 5 part bone structure in their limbs (legs, arms, wings, fins) this is evidence that all organisms evolved from a common ancestor

classification

the grouping of living organisms according to their similarities and differences

plants

multicellular, cells have nuclei, cell walls, chloroplasts for photosynthesis

animals

multicellular, cells have nuclei, no cell walls

Protists

mostly unicellular, can have chloroplasts

prokaryotes

unicellular, flagella, loop of DNA

fungi

multicellular, nuclei, chitin cell walls

Classification system ( dogs keeps calm on fluffy green socks)

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

archea (domain)

cells with no nucleus, genes contain unused section of DNA (prokaryotes)

bacteria (domain)

cells with no nucleus, genes contain no unused sections (prokaryotes)

Eukarya (domain)

cells with nucleus (other 4 kingdoms)

Genus and Species

Binomial Name (homo sapiens)

What was Darwin's theory

theory of evolution by natural selection

Micropropagation

a way of cloning (genetically identical) plants with tissue culture