Classification Flashcards
What is the importance of classification?
Keeps things organised
Can manage large amounts of information
Makes organisms easier to identify
Can identify relationships between organisms
What are the 8 groups/subgroups used to classify things?
Domains Kingdoms Phylum/Phyla Class Order Family Genus/Genera Species
How many domains are there?
3
How many kingdoms are there?
5
What is the taxonomic hierarchy?
All of the groups and sub groups
What is taxonomy?
The science of classifying things
What are the 5 kingdoms?
Animalia Plantae Fungi Prokaryota Protoctista
What does heterotroph mean?
Feed off other things to survive
What does autotroph mean?
Feed by photosynthesis
What are the 4 eukaryote kingdoms?
Animalia
Plantae
Fungi
Protoctista
What is the only prokaryote kingdom?
Prokaryota (bacteria)
What are the features for the animalia kingdom?
Multicellular, mobile, heterotrophs
What are the features for the plantae kingdom?
Multicellular, immobile, roots, stem, leaves, cellulose cell wall
What are the features for the fungi kingdom?
Single or multicellular, can’t photosynthesise, heterotrophs, very branched chitin cell wall.
What are the features for the prokaryota kingdom?
Bacteria, single celled, most common, no nucleus, no membrane bound organelles, 70s ribosomes, peptidoglycan cell wall, microscopic unless in large colonies.
What are the features for the protoctista kingdom?
Normally single celled, have a nucleus, all organisms that don’t fit in the other kingdoms.
What naming system is used for species?
Binomial nomenclature
What is a species?
A group of similar organisms that are able to reproduce to produce fertile offspring.
What are some things to remember when naming species?
Always 2 words Italics if typed/underlined if written Capital first word, lowercase second word First name=genus Second name=species within genus Called a binomial name
When can you abbreviate a species name?
Eg Canis lupus-> C. lupus
The second time you write it.
What type of key is used to identify a species?
Dichotomous key
2 choices each step
Why has classification changed?
Originally only observable features were used as there wasn’t microscopes, biochemistry or DNA evidence
What are the 3 domains?
Bacteria, archaea, eukaryota
What are the features are only in the bacteria domain?
Different cell membrane Flagella Small RNA polymerase Different DNA replication mechanisms Peptidoglycan cell wall
What are the features are only in the archaea domain?
Medium sized RNA polymerase
Extremophiles
What are the features are only in the eukaryota domain?
Nucleus 80s ribosomes Large RNA polymerase Eukaryotic cells Membrane-bound organelles
What are the similarities between the bacteria and archaea domains?
70s ribosomes
No nucleus
What are the similarities between the archaea and eukaryota domains?
DNA binding proteins
DNA replication mechanisms
How do we now classify things?
Anatomy (observable features) Cellular features (using microscopes) Biochemistry (proteins/DNA/RNA)
How do you use proteins to classify organisms?
Work out amino acid sequence of protein
Repeat for different organisms
Look for similarities and differences
Construct an evolutionary relationship
Which 2 proteins are often used to classify organisms?
Cytochrome C
Haemoglobin
What is the problem with using haemoglobin to classify things?
Can’t compare all organisms that don’t have haemoglobin
How do you construct an evolutionary relationship?
Similar sequence = same group
Different sequence = separate groups
Why is cytochrome C usually used to classify organisms?
It is used in respiration so everything has it
What is the problem with using cytochrome C?
Some organisms, like humans and chimps, have the same cytochrome C so that can’t be used to classify them, another protein would be used to classify them.
How do you use DNA to classify organisms?
Look at DNA sequence of a particular gene that ALL things you are comparing have.
More similar=more closely related=same group
More different=less closely related=different group
What are the advantages of using the binomial names instead of the traditional names of organisms?
Every species only has one name (doesn’t change with language/region).
Prevents translation errors (always latin).
A traditional name can apply to several different species.
Which group from the kingdom classification system is split up by the domain system? Why?
Prokaryotae - split into archaea and bacteria as archaea are now thought to be more closely related to eukaryotes than they are to bacteria
How has modern DNA technology contributed to deducing the evolutionary relationships between organisms?
Rapid/accurate sequencing allows us to look at relationships between species.
See how they have evolved/mutated
Closely related=similar genomes
Highlights close relationships between species that look/act differently.
What is a taxon?
Non-overlapping group within a classification
What are certain toxic substances and radioactivity collectively known as?
Mutagens
Cause mutations by ionising radiation
