Classification and Evolution Flashcards
What are the taxonomic groups? (in order)
Kingdom
Phylum
Class
Order
Family
Genus
Species
Who invented the Linnaean system?
Carl Linnaeaus
What is the first level of classification?
The three Domains
What are the three domains?
Archaea
Bacteria
Eukarya
Why do scientists classify organisms?
- to identify species
- to predict characteristics
- to find evolutionary links
- by using a single classification system, organisms can be identified worldwide
Define a species?
a group of organisms that are able to produce fertile offspring
What does binomial nomenclature mean?
Genus then species
What are the five kingdoms?
- Prokaryotae
- Protoctista
- Fungi
- Plantae
- Animalia
What are the general features of Prokaryotae?
- unicellular
- no nucleus or other membrane bound organelles
- small ribosomes
- no visible feeding mechanism
What are the general features of Protoctista?
- mainly unicellular
- a nucleus and membrane bound organelles
- some have chloroplast
- nutrients acquired by photosynthesis and digestion
What are the general features of Fungi?
- uni and multicellular
- nucleus and cell wall containing chitin
- no chloroplasts
- most store food as glycogen
- nutrients are acquired by absorption
What are the general features of Plantae?
- multicellular
- nucleus with membrane bound organelles
- all contain chlorophyll
- food stored as starch
- nutrients acquired by phtotsynthesis
What are the general features of Animalia
- multicellular
- nucleus with membrane bound organelles, no cell wall
- no chloroplast
-food stored as glycogen - nutrients acquired by ingestion
What are the key features of Eukarya?
- have 80s ribosomes
- RNA polymerase, responsible for most mRNA transcription
What are the key features of Archaea?
- have 70s ribosomes
- RNA polymerase of 8 to 10 proteins
What are the key features of Bacteria?
- have 70s ribosomes
- RNA polymerase contains 5 proteins
What are Archaebacteria?
can live in extreme environments
What are Eubacteria?
‘true’ more common bacteria
What is phylogeny?
name given to evolutionary relationships
What are the advantages phylogenetics?
can be used to compared to classification systems
- scientists are forced not force classifications
- classification systems imply organisms are similar even though they may not be
What did Charles Darwin invent?
Theory of Evolution by Natural Selection
What is the evidence of evolution?
- Palaeontology - study of fossil records
- Comparative anatomy - similarities and diffs between organism’s anatomy
- looking at biochemistry of diff organisms
What is a homologous structure?
Structure that appears different (performs a different function), but has the same underlying structure
What is interspecific variation?
between members of different species
What is intraspecific variation?
differences between organisms within a species
What are the causes of variation?
- genetic mutations
- change in environment
What are the genetic causes of variation?
- Alleles (genes have different alleles
- Mutations (change in DNA sequence - genes - proteins that are produced)
- Meiosis (two parents genetic material mixed)
- random fertilisation
What is discontinuous variation?
no in between values, variation determined purely by genetic factors fall into this category
What is continuous variation?
a characteristic that can take any value from one extreme e.g. height
What are normal distribution curves?
when continuous variation data is plotted onto a graph, result in bell shaped curve
What are the three types of adaptations?
- anatomical - physical features
- behavioural - the way an organism acts
- physiological - the processes that take place inside on organism
What are 3 examples of anatomical adaptations?
- body covering
- camouflage
- teeth
- mimicry
What are three examples of behavioural adaptations?
- survival behaviours e.g. playing dead
- courtship
- migration
What are 3 examples of physiological adaptations?
- poison production
- antibiotic production
- water holding
What are analogous structures?
when they perform the same role, but the structure is very different
Why does natural selection occur?
due to selection pressures, or change in the environment
What is the process of natural selection?
- organisms within a species begin to show variation, which means there are different alleles present within the population
- the organisms that are best adapted to the selection pressure (have the advantageous allele) have increased chance of survival
- This means that they are more likely to outcompete, survive and reproduce
- They pass on the advantageous allele to their offspring making it more widespread in the population
