10.1 & 2 Classification Flashcards
What is classification?
Name given to the process by which living organisms are sorted into groups
7 taxonomic groups
Kingdom Phylum Class Order Family Genus Species
Who invented hierarchical classification?
Carl Linnaeus
Why do scientists classify organisms?
To identify species
To predict characteristics
To find evolutionary links
Benefits of using a single classification system
Scientists worldwide can share research
Links between different organisms can be seen, even on different continents
What are the 3 domains?
Archaea
Bacteria
Eukarya
What types of cells are in each domain?
Bacteria - prokaryotes
Archaea - prokaryotes
Eukarya - eukaryotes
Definition of species
Group of organisms that can reproduce to produce fertile offspring
What is produced when a horse is bred with a donkey?
A mule or hinny
Why are mules or hinnies infertile?
They have an odd number of chromosome - 63
Human classification
Domain - Eukarya Kingdom - Animalia Phylum - Chordata Class - Mammalia Order - Primates Family - Hominidae Genus - Homo Species - Sapiens
In binomial nomenclature what do the 2 parts show?
1st part - genus
2nd part - species
How is the binomial name written?
Italicised or underlined
Advantages of binomial nomenclature
Simple meaningful and universally accepted
Easy to understand
Shows evolutionary history of species
Distinguish species from others
Since when were animals classified into kingdoms?
From 1960s
5 kingdoms
Prokaryotae Protocista Fungi Plantae Animalia
Which kingdoms are prokaryotes?
Prokaryotae
Which kingdoms are eukaryotes?
Protocista
Fungi
Plantae
Animalia
Features of Prokaryotae
Unicellular Cell wall and cytoplasm No nucleus or membrane bound organelles Rings of naked DNA 70s ribosomes Divide by binary fission Autotrophic feeders
Eg of Prokaryotae
Escherichia coli
Staphylococcus aureus
Bacillus anthracis
Protocista features
Mostly unicellular A nucleus and other membrane bound organelles Some have chloroplasts Some move by cilia Autotrophic and heterotrophic feeders
Two types of Protocista
Protozoa - no cell wall
Algae - cellulose cell wall and chloroplast
What are autotrophic feeders?
Nutrients are obtained by photosynthesis
What are heterotrophic feeders?
Nutrients are obtained by ingestion of other organisms
Eg of Protocista
Paramecium
Amoeba
Features of fungi
Unicellular or multicellular
Nucleus and other membrane bound organelles
Cell wall of chitin
No chloroplasts or chlorophyll
No mechanisms for locomotion
Most have body or myecelium made of threads or hyphae
Nutrients acquired by absorption - saprophytic feeders
Most store food as glycogen
Eg of fungi
Mushroom
Moulds
Yeast
Features of Plantae
Multicellular
Nucleus and other membrane bound organelles including chloroplasts
Cell wall of cellulose
All contain chlorophyll
Most don’t move - gametes move using cilia or flagella
Nutrients acquired by photosynthesis- autotrophic feeders
Store food as starch
Features of Animalia
Largest kingdom
Multicellular
Nucleus and other membrane bound organelles
No chloroplasts and cell wall
Sometimes have cilia/flagella/contractile proteins
Nutrients acquired by ingestion - heterotrophic feeders
Food stored as glycogen
What were classification systems originally based on?
Observable features
How are scientists now able to study evolutionary links between organisms?
Study of genetics and biological molecules
What happens when organisms evolve?
External and internal features change, as well as DNA
DNA determines the proteins that are made, which determines characteristics
For characteristics to change, proteins have to change as well
How many polypeptide chains in haemoglobin?
4
Who came up with the 3 domain system?
Carl Woese
How does Woese’s system group organisms?
Using differences in sequences of nucleotides in the cells ribosomal RNA, cell’s membrane lipid structure and sensitivity to antibiotics
How are organisms classified under 3 domain system?
Into 3 domains and 6 kingdoms
rRNA and ribosomes in Eukarya
80s ribosomes
RNA polymerase contains 12 proteins
rRNA and ribosomes in Archaea
70s ribosomes
RNA polymerase contains 8-10 proteins
rRNA and ribosomes in Bacteria
70s ribosomes
RNA polymerase contains 5 proteins
What is different in Woese’s system?
The Prokaryotae kingdom is divided into two - Archaebacteria and Eubacteria
Why are Eubacteria classified in their own kingdom?
Their chemical makeup is different from Archaebacteria
They contain peptidoglycan in the cell wall, but Archaebacteria do not
Archaebacteria characteristics
Can live in extreme environments
Eg hot thermal vents, anaerobic conditions, highly acidic environments
Eubacteria characteristics
Found in all environments
Most bacteria are in eubacteria kingdom
