4.3 - classification & evolution Flashcards
What is classification?
The arrangement of organisms into groups of various sizes on the basis of shared features.
What is the binomial system?
A system that uses the genus name and the species name to avoid confusion when naming organisms.
Why do we classify living things?
- convenience
- make the study of living things more manageable
- easier to indentify organisms
- to help us see the relationships between species
What are the eight parts to the modern classification hierarchy?
- Domain
- Kingdom
- Phyllum
- Class
- Order
- Family
- Genus
- Species
What are the 3 domains?
- archaea
- eubacteria
- eukaryotae
Which of the four kingdoms have a nucleus?
- plantae
- animalia
- fungi
- protoctista
What is the kingdom that doesn’t have a nucleus?
prokaryotae
What is the binomial naming system?
A universal naming system that uses the genus and the species.
What are the features of the binomial naming system?
The genus has a capital letter, and the species is written in all lower case.
Italics are used in printed text whereas the name is underlined when handwritten.
What is the biological definition of species?
The group of organisms that can freely interbreed to produce fertile offspring.
What is the phylogenetic definition of a species?
A group of individual organisms that are very similar in appearance, anatomy, physiology, biochemistry and genetics.
What is the description of the kingdom animalia?
- Eukaryotic
- multi cellular
- usually able to move around
- heterotrophic
What does heterotrophic mean?
When you digest large organic molecules into smaller ones that can then be absorbed.
What does autotrophic mean?
When you absorb simple molecules with larger organic ones.
Was a description of the kingdom fungi?
- eukaryotic
- chitin cell walls
- single-celled or have mycelium
- multinucleate cytoplasm
Was a description of the kingdom plantae?
- eukaryotic
- multi cellular
- cellulose cell walls
- contain chlorophyll
- autotrophic
What is the description of the kingdom protoctista?
- eukaryotic
- mostly single celled
- mostly free-living
- plant-like or animal-like features
What is the description of the kingdom prokaryotae?
- no nucleus
- naked DNA (no histones)
- smaller ribosomes
- no membrane-bound organelles
- smaller cells
- DNA loop with non-linear chromosomes
What is taxonomy?
A form of classification that focuses on physical similarities between different species for ease of naming and identification.
What is phylogeny?
The classification of organisms by their evolutionary relationships so that every group shares a common ancestor.
What is the problem with artificial classification?
Sometimes different animals aren’t related, but look very similar due to convergent evolution, which leads to species being put into the same genus of family when they shouldn’t be.
What is artificial classification based on?
- observable characteristics
- diet
- habitat
What is natural classification based on?
- genetics
- reproductive relationships
What evidence is used in classification?
- cytochrome C
- DNA
- the 3 domains
What is cytochrome c?
a protein used in respiration by all organisms, however it is not identical in all species
how can cytochrome C be used?
We can compare the sequence of amino acids in samples of cytochrome C from 2 different species.
What can what two conclusions can be made when comparing cytochrome C from 2 different species?
- if the sequences are the same, the 2 species must be closely related.
- If the sequence is different, the two species aren’t closely related.
How can DNA be used as evidence in classification?
DNA is a universal code for all organisms. You can compare the DNA sequences to help classify the species.
Bacteria is different to archaea and eukaryotae because bacteria have….
- a different cell membrane
- a different internal flagella structure
- different enzymes for synthesising RNA
- no proteins bound to their genetic material
- different mechanisms for DNA replication and RNA synthesis.
What features do archae share with eukaryotes?
- Similar enzymes for synthesising RNA
- Similar mechanisms for DNA replication and RNA synthesis
- Production of same proteins that for bind for DNA.
What is natural selection?
where features of the environment apply selective force on the reproduction of individuals in a population.
Who published papers on evolution by natural selection?
Charles Darwin and Alfred Russell Wallace.
What four observations did Darwin make?
- offspring generally appear similar to their parents
- no two individuals are identical
- organisms have the ability to produce large numbers of offspring
- populations in nature tend to remain fairly stable in size.