Classification Flashcards
What is classification?
Organising every living thing into groups
Why is classification seen as tentative?
New evidence from biochemistry may mean that groups change
What does phylogenetic mean?
Organisms in the same group are more closely related
What is each level in the taxonomic hierarchy called?
A taxon
What are the seven different taxonomic levels?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is a binomial name?
A Latin name for the animals
Why are binomial names used?
So it is the same in all languages
What is a species?
A group of organisms that can interbreed and produce fertile offspring
What is the first part of the binomial name?
The genus of the organism
What is the second part of the binomial name?
The species of the organism
What are the three domains?
Eubacteria
Archaea
Eukarya
What are eubacteria?
‘True’ bacteria - prokaryotes
What are archaea?
Extremophile prokaryotes
What are eukarya?
All eukaryotic organisms (true membrane bound nucleus)
What are extremophiles?
Organisms that live in a harsh environment
What are the four different types of extremophiles?
Thermophiles
Halophiles
Psychrophiles
Methanophiles
What are thermophiles?
Organisms that live in hot places
What are halophiles?
Organisms that live in salty environments
What are psychrophiles?
Organisms that live in cold places
What are methanophiles?
Organisms that produce methane
What are the five different kingdoms?
Animalia
Plantae
Protoctista
Fungi
Prokaryotae
What are the features of prokaryotae?
No membrane bound nucleus/organelles
70s ribosomes
Peptidoglycogen wall
Unicellular
Heterotrophic or autotrophic
What are the features of animalia?
Multicellular, eukaryotes
No cell wall
Heterotrophic - holozoic nutrition
Nervous coordination
What are the features of plantae?
Multicellular, eukaryotic
Cellulose cell wall
Autotrophic
What are the features of fungi?
Multi or unicellular, all eukaryotic
Chitin cell wall
Heterotrophic - saprotrophic nutrition
Reproduce by spores
Hyphae
What are the features of protoctista?
Unicellular, prokaryotic
Heterotrophic, autotrophic or both
Diverse grouping
What is a phylogenetic tree?
A diagram that represents the evolutionary pathways leading to different species
What is a clade?
A group of branches from one common ancestor
How can evidence for relatedness be shown?
Using DNA, RNA and proteins - compare the sequences and count the differences
Would having more differences in their RNA/DNA mean the organisms are more or less closely related?
Less due to more mutations
What happens in gel electrophoresis?
Gel allows small molecules to move further
Electrical charges cause movement of negatively charged DNA fragments to + electrode
Produces a DNA fingerprint which can be used for comparison
What is morphology?
Looking at the shape and form of an organism
What are homologous structures?
Similar structures with different functions e.g. pentadactyl limb - same structure in mammals, birds and reptiles but different functions
Shows relatedness
Divergent evolution
What are analogous strutures?
Function is the same but origin is different e.g. bird and insect wings
Convergent evolution
What is divergent evolution?
The process where two or more species, sharing a common ancestor, evolve in different directions, resulting in increasingly dissimilar traits
What is convergent evolution?
The process where unrelated species develop similar traits or adaptations due to inhabiting similar environments and facing similar selective pressures
What is biodiversity?
Number of species and number of individuals of each species in a given area
How is biodiversity arranged on the planet?
Spatially, increases from poles to the equator
Why does biodiversity increase the closer to the equator you are?
More UV causes more mutations and more rapid evolution
More species = more habitats and niches
More stable environment = increased chance of survival
How can biodiversity be measured?
Gridding - compare two areas
Transects - gradual environment change
Kick sampling in a stream - place net downstream of kicking area
What are the hazards in field work?
Biting and stinging insects/plants
Slippery surfaces
Sunburn
What is Simpsons diversity index?
(0-1) - if closer to 1 then more biodiversity
Diversity Index (D) = N(N-1) / Σn(n-1)
