4.3 - Classification and Evolution Flashcards
Why do we classify organisms?
- For convenience for more manageable study of organisms
- To make it easier to identify organisms
- To help see relationships between organisms
List the 8 taxonomic groups:
Domain Kingdom Phylum Class Order Family Genus Species
Variation shown by organisms in each taxonomical group
Variation decreases going down taxonomic groups.
Down from Domain to Species
How closely are species related in taxonomic groups?
Relation increases down the taxonomic groups
Increases down form domain to species
Why do classification systems change over time?
- scientific knowledge changes as new discoveries are made
- technological developments lead to new discoveries;
- named technological development; e.g. microscopes, new DNA technology
- differences of opinion amongst biologists/scientists
In which classification level is the most variation seen?
Domain
In which classification level is the least variation seen?
Species
State the 8 levels of classification
Domain Kingdom Phylum Class Order Family Genus Species
Why do common names for organisms have limitations in classification?
- Same species have different common names in different places
- Different languages would give different common names
- Same common name could be used for different species in different places
What language is the binomial naming system in?
Latin
How is the binomial name formed?
First word: Genus - capital letter
Second word: Species - lower case letter
Written in italics or underlined
Classification def
Process of sorting lining things into groups of similar organisms.
It reflects how closely related they are and evolutionary relationships
Taxonomy def
The study of the principles behind classification
- the study of the differences between species(physical and genetic)
Phylogeny def
The study of the evolutionary relationships between organisms
- the study of how closely related they are
List the five different kingdoms
- Prokaryotae
- Protoctista
- Fungi
- Plantae
- Animalia
Description of prokaryotae kingdom
- have no nucleus
- have a loop of DNA that is not arranged in linear chromosomes
- have named DNA(DNA that is not associated with histone proteins
- Have no membrane-bound organelles
- Have smaller ribosome than in other groups(70S)
- Have cells smaller than those of eukaryotes
- May be free-living or parasitic(some may cause diseases
Description of protoctista
- Are eukaryotic
- are mostly single-celled(but many algae are multicellular
- show a wide variety of forms(the only thing protoctists have in common is that they do not qualify to belong to any of the other four kingdoms!)
- show various plant#like or animal-like features
- are mostly free-living
- have autotrophic or heterotrophic nutrition - some photosynthesise, some ingest prey, some feed using extra cellular enzymes(like fungi), and some are parasites
Fungi Description
- are eukaryotic
- can exist as singe cells(called yeasts) or have a mycelium that consists of hyphae
- have cell walls made of chitin
- have a cytoplasm that is multinucleate
- are mostly free-living and saprophytic- meaning they can cause a decay of organic matter
Plantae description
H
Animalia description
H
Heterotrophic feeder meaning
Eat and digest other organisms
Autotrophic feeder meaning
Use photosynthesis to produce their own food
Saprotrophic feeder meaning
Digest other organisms outside the body using extra cellular enzymes
Hierarchy def
Groups within groups with no overlap
Species def
-A group of organisms similar in appearance, physiology and genetics whose members are able to interbreed to produce fertile offspring
5 forms of vertebrates
- Mammals
- Birds
- Fish
- Reptiles
- Amphibians
It has been found that 98.4% of chimpanzee DNA is identical to that of a human.
(i) Suggest how the information obtained by DNA analysis can be useful to taxonomists.
(2 Marks)
- Information can be used to decide which species an organism fits into; easier to classify organisms
- compare DNA base sequences between organisms - the more similar the base sequences, the more closely related the two organisms are.
State two types of evidence, other than biochemical evidence, that are used by taxonomists when classifying organisms.
(2 Marks)
- Fossil records
- Physiology/anatomy/behavioural characteristics
- embryology
