4.2.2 - Evolution and classification Flashcards
What is classification ?
Classification is the name given to the process by which living organisms are sorted into groups
What are the 7 taxonomic groups ?
- Kingdom
- Phylum
- Class
- Order
- Family
- Genus
- Species
What is an easy way to remember the taxonomic groups ?
King Phillip Came Over For Good Spaghetti
Why do scientists classify organisms ?
- To identify species, by a clearly defined system of classification
- To predict characteristics
- To find evolutionary links, species in the same group probably have a common ancestor
What are the benefits of using a single classification system ?
By using a single classification system, scientists worldwide can share their research as links between different organisms can be seen
What are the three domains ?
- Archaea
- Bacteria
- Eukarya
Define species
Defined as a group of organisms that are able to produce fertile offspring
How do scientists name organisms ?
Binomial nomenclature
What is binomial nomenclature ?
The two name system of naming organisms using genus and species
Why is binomial nomenclature used ?
To ensure that scientists are discovering/discussing the same organisms, which could otherwise be a problem because of language barriers
What are the five kingdoms ?
- Prokaryotae (Prokaryotes)
- Protoctista (Eukaryotes)
- Fungi (Eukaryotes)
- Plantae (Eukaryotes)
- Animalia (Eukaryotes)
What are heterotrophs ?
A heterotroph is an organism that eats other plants or animals for energy and nutrients
What are autotrophs ?
Organisms that use an external energy source to assimilate inorganic resources from the environment and synthesize the biological molecules needed to sustain life
What are saprotrophs ?
Organisms that eat decayed organic matter
What are the characteristics of the kingdom Animalia ?
- Eukaryotic
- Multicellular
- Membrane bound organelles
- Heterotrophic feeders
- No cell walls
- Store food as glycogen
What are the characteristics of the kingdom Plantae ?
- Eukaryotic
- Multicellular
- Chloroplasts
- Membrane bound organelles
- Autotrophic feeders
- Cellulose cell walls
- Food stored as starch
What are the characteristics of the kingdom Fungi ?
- Eukaryotic
- Multicellular or unicellular
- Membrane bound organelles
- Chitin cell walls
- Most saprotrophic feeders
- Store food as glycogen
What are the characteristics of the kingdom Prokaryotae ?
- Prokaryotic
- Unicellular
- No membrane bound organelles
- Peptidoglycan cell walls
- DNA not associated with histones
- DNA circular
What are the characteristics of the kingdom Protoctista ?
- Mainly unicellular
- Nucleus and membrane bound organelles
- Some have chloroplasts
- Some are sessile, but others move by cilia or flagella
- Nutrients are acquired by photosynthesis - Autotrophic, ingestion of other organisms - Heterotrophic, or both - Parasitic
What are the 3 domains ?
- Bacteria
- Archae
- Eukarya
Describe Bacteria
- Have 70s ribosomes
- RNA polymerase contains 5 proteins
Describe Archaea
- Have 70s ribosomes
- RNA polymerase contains between 8-10 proteins
Describe Eukarya
- Have 80s ribosomes
- RNA polymerase contains 12 proteins
Under the 3 domain system, how many kingdoms are there ?
6
Under the 3 domain system, what are the 6 kingdoms ?
- Eubacteria
- Archaebacteria
- Protoctista
- Plantae
- Fungi
- Animalia
Describe Archaeabacteria
- Ancient bacteria
- Can live in extreme environments, thermal vents, anaerobic conditions and highly acidic environments
Describe Eubacteria
- True bacteria
- Found in all environments
- Most bacteria are of the eubacteria kingdom
Give 3 similarities between the domains of Bacteria and Archae
- Circular chromosomes
- No nucleus
- 70s ribosomes
Give a similarity between the domains of Bacteria and Eukarya
Normal phospholipids in membranes
Give 3 similarities between the domains of Eukarya and Archae
- Similar DNA replication
- Histones bound to DNA
- No peptidoglycan cell walls
- Not susceptible to antibiotics
- Similar RNA polymerase
