Chaper 10- Classification Flashcards
(24 cards)
What is the hierarchy order in the classification system?
Kingdom
Phylum
Class
Order
Family
Genus
Species
What is a node on a phylogram?
Where two lines meet?
What three reasons for classification?
- To identify species
- To predict the characteristics of new unidentified species
- To discover evolutionary links and common ancestors
What is the definition of a species?
A group of organisms that are able to reproduce to produce fertile offspring
What comes first genus or species?
Genus then species
Why can closely related species breed and what’s the problem with this?
They can produce offspring but they are not fertile therefore they don’t meet the biological definition of a species
Why can’t two species produce fertile offspring?
The two species that are closely related won’t have the same number of chromosomes which means that the offspring have an odd number of chromosomes and so can’t produce gametes by meiosis
What are the five kingdoms?
Prokaryotae (bacteria)
Protoctista (eukaryotic single or multicellular)
Fungi (yeasts, moulds and mushrooms)
Plantae
Animalia
What is prokaryotae?
Unicellular
Lacks a membrane enclosed nucleus
No membrane bound organelles
Nutrients are absorbed through cells surface membranes
Asexual and reproduce by binary fission
What is protista?
Any eukaryotic organism that isn’t an animal, plant or fungus
Unicellular
Nucleus and other membrane bound organelles
Some are sessile (no movement)
Food from other sources
What is fungi?
Yeasts,moulds and mushrooms
Membrane bound organelles and nucleus
Contain chitin in the cell wall
No chloroplasts
Sessile
Glycogen stores
Saprophytic (absorbs nutrients)
A body (mycelium) made from threads of hyphae
What are plantae?
Nucleus and membrane bound organelles
Contains chloroplast
Cell wall of cellulose
Mainly sessile but some move by flagella or cilia
Nutrients required via photosynthesis making them autotrophic
Starch reserves
What are animalia?
No cell walls or chloroplasts/chlorophyll
Motile
Nutrients required via ingestion so they’re heterotrophic
Glycogen reserves
How does modern classification work?
Combines observable features with evolutionary history of evolutionary relationships of organisms.
What is the modern classification system based on?
1)Genetics - both DNA and RNA sequences
2)Comparative biochemistry- the study of differences between proteins
What type of ribosomes does bacteria have?
70s
What RNA polymerase does bacteria have?
5 subunits
What ribosomes do archaea have?
70s but closer to eukaryotic ribosomes in base sequence
What RNA polymerase does archaea have?
varies between 8 and 10 subunits
What ribosomes do eukarya have?
80s ribosomes
What RNA polymerase does eukarya have?
12 subunits
What is Phylogeny?
The study of evolutionary relationships and history between organisms
Where does evidence for phylogeny come from?
RNA and DNA base sequences
Amino acid sequences in proteins
The fossil record
What is a phylogenetic tree?
A diagram that shows the evolutionary relationships between organisms and their common ancestor
