Chapter 10 - Classification And Evolution Flashcards
What is classification
And why is it useful
The act of arranging animals and plants in taxonomic groups according to their observed similarities
Provides information about organisms
Provides information about relationships between organisms
Easier for scientists to share information
What is taxonomy
The study of classification
What are taxonomic groups
The hierarchical groups of classification
Why do scientists classify organisms
To identify species
- species an organism belongs to is easily identified
To predict characteristics
- species in the same group likely to share characteristics
To find evolutionary links
- similar species likely to share a common ancestor
Easier to share research worldwide
- links between different organisms around the world can be seen
3 domains
Archaea
Bacteria
Eukarya
Taxonomic hierarchy named
Domain Kingdom Phylum Class Order Family Genus Species
Name all 5 kingdoms
Animalia Prokaryotae Plantae Protoctista Fungi
Features used to classify organisms into
Prokaryotae
Bacteria = ecoli
Unicellular Prokaryotic No nucleus No membrane bound organelles Less than 5um
No visible feeding mechanism
Features used to classify organisms into
Protoctista
Algae, protozoa, amoeba
Eukaryotic
Unicellular mainly
Usually live in water
Some have chloroplasts
Features used to classify organisms into
Fungi
Mushrooms , moulds, yeast
Eukaryotic Unicellular or multicellular Have nucleus and membrane bound organelles Chitin cell wall No chloroplasts or chlorophyll Food stored as glycogen
Saprophytic feeders
Features used to classify organisms into
Plantae
Flowers, mosses, ferns
Multicellular Cellulose cell wall Has nucleus and membrane bound organelles Has chloroplasts and chlorophyll Food stored as starch
Autotrophic feeders
Features used to classify organisms into
Animalia
Molluscs, reptiles, nematodes
Multicellular No cell wall Nucleus and membrane bound organelles No chloroplasts Food stored as glycogen
Heterotrophic
What is a saprotrophic feeder
Absorb substance from dead or decaying matter
What is an autotrophic feeder
Produces their own food
What is a heterotrophic feeder
Consumes plants and animals
How to use nomenclature
Called the binomial system
Genus + species
Underlined
Advantages of the binomial system
- organism can be easily classified
- helps avoid confusion, each name is unique
- universal recognition
- useful in identifying relationships between organisms
What is phylogeny
The study of the evolutionary history of groups of organisms
Reveals which organism is related to and how closely related
What is the relationship between classification and phylogency
Phylogeny is used to confirm that the classification groups are correct, and if not, causes them to change
Advantages of phylogeny
Takes into account evolutionary relationships
Forms a continuous tree so organisms don’t have to be forced into a group
Is not hierarchical therefore can be compared
Easy to observe relationships
6 kingdoms vs 3 domains
Prokaryotae split into
Archeabacteria eubacteria
Single celles prokaryotes
What evidence did woese base his new system on
The sequences in nucleotides in the cells ribosomal RNA
The cell membranes lipid structure and their sensitivity to anitbiotics
Eukarya 80s ribosome
Archea 70s ribosome
Bacteria 70s ribosome
Why was the prokaryotae been reclassified into 2 domains
Because there is a large difference between archaea and bacteria
They have evolved separately
Archaea head is more closed related to eukarya
What are the differences between archaea and bacteria
MOLECULAR EVIDENCE
Have different ribosomal RNA
Different enzyme RNA polymerase
Archaea, not bacteria, has similar histones to eukarya
CELL MEMBRANE EVIDENCE
Different bonds of the lipids in the cell membranes
Different development and composition of flagellae
