C10 - Classification and evolution Flashcards
What is classification?
Name given to the process by which living organisms are sorted into groups
What is the most widely used system of classification?
Linnaean classification - hierarchal classification
What are the groups called in hierarchal classification?
Taxonomic groups
What are the seven taxonomic groups in order?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What further level of classification can be added to the hierarchal system?
Domain
Why do scientist classify an organism?
To identify species
To predict characteristics
To find evolutionary links
How are organisms classified?
First separates organisms into 3 domains
Archaea, bacteria, eukarya
Broadest groups
What is a species?
Group of organisms that can reproduce to create fertile offspring
What is significant about number of chromosomes in infertile animals?
They are odd
Meiosis cannot occur correctly as all chromosomes must pair up
How are species named?
Binomial nomenclature
First word is genus
Second word is species
Genus first letter in uppercase
Italics / underlined
What are the 5 kingdoms?
Prokaryotae (bacteria)
Protoctista (unicellular eukaryotes)
Fungi (yeasts, mould, mushroom)
Plantae (plants)
Animalia (animals)
General features of prokaryotae?
-Unicellular
-No nucleus or membrane bound organelles
-No visible feeding mechanism
General features of protoctista?
-(mainly) unicellular
-Nucleus and membrane bound organelles
-Some have chloroplasts
-Nutrients acquired by photosynthesis or ingestion
What is autotrophic?
Organisms that synthesise complex molecules from inorganic molecules via photosynthesis
What is heterotrophic?
Organisms that acquire nutrients by the ingestion of other organisms
General features of fungi
-Unicellular or multicellular
-Nucleus and membrane bound organelles
-Cell wall composed of chitin
-No chloroplasts
-No mechanisms for locomotion
-Most made of thread or hyphae
-Nutrients acquired by absorption
-Store food as glycogen
What is saprophytic
Organisms that acquire nutrients by absorption - mainly decaying material
General features of plantae
-Multicellular
-Nucleus and other membrane bound organelle
-Chlorophyll and chloroplasts
-Do not move
-Nutrients acquired through photosynthesis
-Store food as starch
General features of animalia
-Multicellular
-Nucleus and other membrane bound organelles
-No cell wall
-No chloroplasts
-Move with aid of cilia, flagella,
-Nutrients acquired by ingestion
-Food stored as glycogen
Changes to classification systems
Used to be based on observable features
Now based on evolutionary relationships
What is the three domain system
3 domains are archaea, bacteria, eukarya which have different ribosome and different RNA
then classified into 6 kingdoms
Describe ribosomes and RNA eukarya has
80s
RNA polymerase has 12 proteins
Describe ribosomes and RNA archaea has
70s
RNA polymerase contains between 9-10 proteins
Describe ribosomes and RNA bacteria has
70s
RNA polymerase contains 5 proteins
What are the 6 kingdoms in the 3 domain system
Protoctista
Plantae
Fungi
Animalia
Eubacteria
Archae-bacteria
What is archae bacteria
Ancient bacteria
Can live in extreme environments
What is eubacteria
True bacteria
Found in all environment, maj
Do scientists use 5 or 6 kingdoms
6
What is phylogeny
Evolutionary relationships between organisms
What is a phylogenetic tree
Diagram used to represent evolutionary relationships between organisms