Classification and biodiversity Flashcards
Phylogenetic
refelcting evolutionary relatedness
Phylogenetic tree
Diagram showing evolutionary descet wiht living orgaisms at the tip of the branches ancestral species in the branches and trunk and branch points representing common ancestors
What is the phylogenetic method
- Bilogists use a method that reflects an organism’s revolutionary history
- grouping closely related organisms togehter
What do organisms in the same group in the phylogenetic method have in common
- organisms in same group have more recent common ancestor with each other than with organisms not in their group
- if there closely related they may show physical similarities
Taxonomy
The identification and naming of organisms
Classification
Putting items into groups
Hierarchy
A system of ranking in which small group are nested componenets of larger groups
What is a taxon
Any group within a system of classification
what can you see with small groups that are contained within bigger groups
- members of each group are more similar to each other than to members of other groups.
What is a hierarchical system
- syste in which smaller groups are componenets of larger groups
- has been devised for living organisms
- each grouping in the system is a taxon (plural = taxa)
- Bigger taxa contain smaller taxa
- Within each taxon organisms are more similar to each other and more closely related than to organisms outside the taxon
Wha is the hierarchy of biological classification
- domain
- kingdon
- phylum
- class
- order
- family
- genus
- species
What happens as you move down the hierarchy
- from domain to species organisms in a taxon are more closely related
- moving up hierarchy from specides to domain members of a taxon are less closely related
What are taxa
- taxa are discrete at any level of classification and organism belongs in one taxon and in no other
- discrete is individually seperate and distinct
Why do we need a classification system
- a phylogenetic classification system allows us to infer evolutionary relationships. If two organisms are so similar that we put them in the same taxon, we infer that they are closely related
- if a new animal is discovered with a beak and feathers we predict ome of its other characterisistics based on our general understanding of birds
- when we communicate it is wuicker to same bird than to say the full name
- when describing the helathy of an ecoystem or the rate of extinction in the geological record, conservation soften find it more useful to count families than species
What is a problem with the classification systen
- it is tentative
- clasification depends on our current knowledge
What is the three domain system
- it’s the largest taxon and all living things belong in one of three domains
- domain were originally defined on the basis of rRNA base sequences
- more modern methods of analysis also conider similariies in the DNA sequence
What are the three different domains
- eubascteria: these are the familiar bacteria such as e coli and salmonella they’re prokaryotes
- archar: thee are bacteria and often have unusual metabolism for example some generate methane and live in marginal habitat and are also prokaryotes
- eukaryota: plantae, animalia, fungi and protoctista
Wha is the five kindom system
classifies organisms on the basis of their physical appearance
What are the five different kingdoms
- all bacterua eubacteria and archae are in one kindom the prokaryota and the other four kindoms conain eukaryote organisms
What is a phylum
- Is a sub group kindom
- member of each phylum have a distinct body plan
- eg members of the phylim annelida are soft bodiesd and segmented members of the arthropoad jave chitinious exosskeleton and jointed limbs the phylum chordata contains vertebrates
What is a class
- is a subgroup of a phylum eg mammalia form a class within the phylum chordata insecta are a class within the phylum rthropoda
What is a species
- is a group of organisms sharing a large number of physical features and able to interbreed to make fertile offspring
What are prokaryota (prokaryotes)
- prokaryote are microscopic
- this kingsom contains all the bacteria and cyanobacteria
What are protoctista (protoctists)
- some have only one cell and these are major component of planktom others are colonia
- some have many similarcells like seaweeds and algae
What are fungi
- yeasts are single celled
- moulds such as penicllium and mushrooms uch as amanita musscaria have hyphae which weave together to form the body of the fungus a mycelium
- in some cross cell wall called septa sub divide the hyphae
What are plantae (plants)
- mosses, horsetails,and ferns reproduce with spores
- conifers and flowering plants which reproduce with seeds
Describe prokaryota
- organisation - prokaryotic and single celled
- no nucleus
- have a mesosome
- they are photosynthetic and have llamalae in some
- 70s ribsomoes
- no ER
- no vacuole
- peptidoglycan cell wall
- nutrition - saprotrophic, parasitic and autotrophic
- no nervous coordination
Describe protoctista
- Eukaryotic
- single celled or multicellular
- have a nucleus
- have mitochondria
- some contain chloroplast
- 80s ribsomes in cytoplasm
- have endoplasmic reticulum
- some contain a vacuole
- some contain a cellulose cell wall
- some contain no cells walls
- some autotrophic
- some are hetrotrophic
- no nervous coordination
Describe planta
- Eukaryotic
- multicellular
- contain a nucleus
- contain mitochondria
- contain chloroplasts
- contain 80 s ribosomes in cytoplasm
- have an endoplamsic reticiculum
- large central permanent vacuole
- celluloe cell wall
- autotrophic
- no nervous co ordination
Describe fungi
- Eukaryotic
- single celled or hyphal
- contain a nucleus
- contain mitochondria
- contain no chloroplasts
- contain 80s ribosomes in cytoplasm
- contain endoplasmic reticulum
- contain large central permanent vacuole
- chitin cell wall
- saprotrophic or parasititc
- no nervous co ordination