classificaiton Flashcards
what is a classification system
The name given to the process by which living organisms are sorted into groups
the organisms
Natural classification
Natural classification systems use EVOLUTIONARY relationships - ancestors and structural features
Order of classification = organisms have more characteristics in common as you descend
Artificial classification
Grouped on observable features e.g. flying
Order of classification
Kingdom Phylum Class Order Family Genus Species
King Phillip can only find green socks
What are heirarchical systems called ?
Linneaus classification after 18 centuary Swedish botanist Carl linneaus proposed the system
What happens to the number of groups / organisms at each level ??
As you descend, there are more groups at each level but fewer organisms in each group. The organisms in each group become more similar and share more characteristics
What are domains ?
Further classification
BROADEST GROUPS
Archae , bacteria and eukaryae
Species ?
Smallest unit of classification
Each group can only contain one type of organism
Group of organisms that can reproduce to produce fertile offspring - e.g. horse and donkey can breed but offspring is in fertile - they are in a different species and the offspring is not a species
Why do we need classification ?
Identify species - easily identify , clearly defined system
Evolutionary links - species in the same group probably have a common ancestor ( they have evolved from this and therefore share characteristics)
Predict characteristics - if several members have specific characteristics , its likely another specifies in the group will have similar
Share research easily - links between different organisms can be seen - even if they live on different continents
Binomial nomenclature for animal
Genus = capital Species = lower case after
Italics or underlined
What are the 5 kingdoms
Prokaryotes Protoctista Fungi Animalia Plantae
Prokaryotae
Unicellular
No nucleus of other membrane bound organelles
Ring of naked DNA
Small ribosomes
No visible feeding mechanisms - nutrients are absorbed through fbe cell wall or produced internally by photosynthesis
Protoctista
Mainly unicellular
Nucleus and other membrane bound organelles
Some have chloroplasts
Dustin kingdom
Some are sessile but others move by cilia , flagella or by aoneboid mechanisms
Photosynthesis or indigestion of other organisms or btoh or parasitic
Fungi
Uni or multicellular
A nucleus and other membrane bound organelles and cell
Wall ( chitin £
No chloroplasts or chlorophyll
No mechanism for locomotion
body or mycelium made of threads of hyphae
Nutrients squired by absorption - mainly from decaying matter and some are parasitic
Store food as glycogen
What does sessile mean
Immobile
Plantae
Second largest kingdom - over 250,000 species
Multicelllular
Nucleus and other membrane bound organelles eg chloroplast and a cell wall - mostly composed of cellulose
CHLOROPHYLL
Most do not move although gametes of some plants move using cilia and flagella
Nutrients acquired by photosynthesis
Store food as starch
Animalia
Largest kingdom - over 1 mlionspecies
Multicellular
Nucleus and other membrane bound organelle
No chloroplasts
Move with th aid of cilia flagella it contractile proteins , sometimes in the form of muscular organs
Nutrients squired by injection and stored as glycogen
Types f feeders
Autotrophic
Saprophytic
Heterotrophic
Autotrophic
Made their own food
Saprophytic
Absorption of nutrients
Heterotrophic
Nutrients aquired by injesting other organisms t
Dna - evolution
DNA must change in order for charactersfics fo change - DNA determines proteins made which in turn determines that
Comparing similarities and differences in dna and proteins of different species , scientists can discover evolutionary relafimshsip between then
6 kingdoms and 3 domains idea
The current classification system is known as the 3 domain system
Proposed by Carl woese
Groups organised using differences in the sequences of nucleotides in the cells rRNA as well as he cells membrane lipid structure
What are the 3 domains and are they different within the domains
Archae bacteria eukaryotee
Within each domain- UNIQUE set of RNA and different ribosomes
What is the kingdom for bacteria and archae
Bacteria - eubacteria
Archae - archae bacteria
Eukarya kingdoms
Fungi , animalia plantae and protoctista
Compare archaebacteria and eubacteria
Both prokaryotes
Chemical makeup different
EU have peotidoglycan cell wall
Eukarya domain
80s ribosomes
RNA polymerase contains 12 proteins
Archae domain
70s ribosomes
RNA polymerase 8-10 proteins c similar to eukaryotic ribosome
Bacteria domain
70s ribosomes
RNA polymerase - 5 proteins
What is phylogeny
The study of evolutionary relationships between organisms ( phylogenetics)
Which group of an organism is related and how closely related they are
What are phylogenetic trees
Diagram used to present evolutionary relationships between organisms
BRANCHED - show the species have a common ancestor
Advantages of phylogenetic trees
- Can be done without reference to classification and classification can be confirmed
- Produces a continuous trees whereas classification requires discrete taxonomical groups - not forced to our organisms into a specific group
- Classification can be misleading as it’s heirarchical - 2 organisms in different families implies they are equivalent fbecause they ad 2 groups in the same rank eg cats and orchids are both families
