Classification Flashcards
What is classification?
The process of sorting living things into groups and naming them and organisms are grouped according to how physically similar they are
What is the classification hierarchy?
Domain, kingdom, phylum, class, order, family, genus and species
What is taxonomy?
Science of finding, describing, classifying and naming organisms including tidying the relationships between taxa and the principles underlying classification
What is phylogeny?
Study of how closely different species are related, reflecting evolutionary relationships between organisms and using DNA/RNA analysis to find out how closely related both extinct and extant species are
What is the effect of evolution?
A wide variety of organism with a common ancestry so they can be classified
What is the intention of classification?
Imposing a hierarchy on variety
What is the purpose of classification?
Identify species, predict characteristics and find evolutionary links
What is the purpose of using the same classification system worldwide?
Scientists can globally share their findings
What are the 3 domains?
Bacteria, archaea and eukaryotae
What are characteristics of bacteria?
Eubacteria, with 70s ribosomes and RNA polymerase contains 8-10 proteins
What are the characteristics of archaea?
Archaebacteria, with 70s ribosomes and RNA polymerase with 5 proteins
What are characteristics of eurkayrotae?
Eukaryotes, with 80s ribosomes and RNA polymerase as 10 proteins
What is the impact of the 3 domains?
Gives clarity as the technology today allows scientists to look at molecular differences and was devised by Woese
How did Woese group organism?
Sequence of nucleotides in the cell’s ribosomal RNA, differences in ribosome small subunit, lipid structure and presence of peptidoglycan in the cell wall
What are the 5 kingdoms?
Prokaryotae, protoctista, fungi, plantar and animal is
What are prokaryote?
2 types of bacteria
What are characteristics of prokaryotes?
Prokaryotic cells, no nucleus, loop of naked DNA cell wall made of peptidoglycan, no membrane bound organelles, respiration on mesosomes, smaller ribosomes, cells are smaller than eukaryotes and may be free living or parasitic
What are protoctista?
Eukaryotic cells
What are characteristics of protoctista?
Mostly single celled, wide variety of forms, various plant-like features, mostly free-living, autotrophic of heterotrophic and dont qualifying for 4 other kingdoms
What are fungi?
Eukaryotic cells
What are characteristics of fungi?
Mycelium made of hyphae, chitin cell walls, cytoplasm not usually divided into cells, mostly free-living and saprophytic
What are plantae?
Eukaryotic cells
What are characteristics of plantae?
Multicellular, cellulose cell walls, produce multicellular embryos from fertilised eggs and autotrophs
What are animalia?
Eukaryotes
What are characteristics of animalia?
No cell walls, heterotrophic nutrition, fertilised eggs develop into a ball of cells called a blastula and usually able to move around
How do you group organisms?
- Study characteristics to look for common features
- Refine groupings until reach species level
- Groups are called taxa
How were species originally identified?
Long descriptions or common names
What were issues with past species identification?
Descriptions vary so must be long too accurately distinguish and common names are different n different countries so translation may lead to mistakes
How do you name an organism?
Need capital letter for genus and low case for species, and species is either written in italics or underlined
What are autotrophs?
Organism that make their own food, such as plants
How do autotrophs feed?
Synthesise complex organic molecules from simple organic molecules using an external energy source
What are heterotrophs?
Organism that eat other organism and cannot make their own food
What are saprophytes?
Heterotrophs that feed on dead and decaying matter by breaking it down and absorbing the nutrients
