Taxonomy
Classification Nomenclature
- systematic way to sort organisms - naming of organisms
into groups accor to common
characteristics
- purpose
- study organisms in a systematic way
- identify an organism more easily by matching it with characteristics of one of
the groups
- understand the phylogeny 1of organisms
- make predictions
- Scientists predict effect of a chemical on a new species based on the
effect on known similar species
- Deduce body structures/functions of an ancestor from features of its
descendents
- Taxonomic hierarchy
- today’s system originated from one made by Carolus Linnaeus2 (18th cent.)
- group organisms with similar characteristics into categories arranged at diff
levels
- share same lower hierarchy level, closer phylogenetic relationship,
more recent common ancestor3
- same group: same fundamental similarities; same subgroup: more
similarities
- kingdom > phylum > class > order > family > genus > species
- species = organisms can interbreed to produce fertile offspring4
- similar structural features + genetic materials
- Nomenclature
- universal scientific name w/ 2 Latin words
- printed: italics; written: underlined separately5
genus name species name
- begin with a CAPITAL LETTER - begin with a small letter
- may be abbreviated in later usage - may suggest who/where it was
T. officinale (Taraxacum officinale) discovered
1
evolutionary history
2
father of taxonomy
3
share same higher hierarchy level, less close phylogenetic relationship, common ancestor in more
4
❌
distant past
mule (horse + donkey) (infertile)
horse 64 chromosomes + donkey 62 chromosomes > mule 63 chromosomes cannot pair up properly
during meiotic cell division to produce normal gametes > infertile
5
❌
mule: Equus asinus x Equus caballas
tilt handwriting
,Modern Classification system
- Ancient Greek - 1960s: based on similarities in structural/morphological features6
- Tech advancement: microscopy
- observe cellular structure
- contain chlorophyll and can swim freely > both plant and
animal characteristics > Protista
- presence of membrane bounded organelles > separate
prokaryote and eukaryote
- diff composition of cell wall > Fungi7
- DNA base sequencing8
- determine nucleotide sequence of DNA of diff organisms
- more similar genetic material > closer phylogenetic relationship
- phylogenetic relationship > separate Archaea and Bacteria,
group 4 eukaryotic kingdoms as Eukarya (3 domains)
- Now: based on phylogenetics9
- 3 domain + 6 kingdoms
- less diff rRNA sequence, more similar genetic materials, closer
phylogenetic relationship
- closer branches in evolutionary tree
3 domains
1. Bacteria
- most are harmless
- important for human
survival
2. Archaea
- more ancient
- @extreme environment
- less understanding
- more closely related to
Eukarya than Bacteria
3. Eukarya
- Plants more closely
related to protista than
fungi
- Fungi more closely
related to animals than
plants
6
7
analogies✅ ❌
external observable
X carry out photosynthesis like plants
physiological (use…for…)
8
OR amino acid sequencing OR comparing mRNA of similar protein > #diff by accumulated mutation
9
homologies
, Kingdom Eubacteria10 (from Domain Bacteria)
- v small: 1-5um long (light microscope: high power)
- diff shapes (3 basic)
- rod-shaped bacillus: Escherichia coli
- Spherical coccus: Streptococcus suis
- Spiral spirillum: Helicobacter pylori cause bleeding of stomach
- Nutrition: heterotrophic (saprophytic11 / parasitic) / autotrophic12
- Motion: motile / non-motile
- Reproduction: by binary fission/spore
- live in a variety of habitat (air, water, soil, inside other organisms)
- important in material cycling in ecosystem
- some can cause diseases to humans, fungi, plant (eg. cholera)
Cell wall Unicellular
- X cellulose, prokaryote
peptidoglycan - X true nucleus
- Bacterial
Cell membrane chromosome
- bacterial / lie free in
eukaryotic cytoplasm
phospholipid circular DNA
bilayer - X membrane
-bounded
Plasmid13 organelles
- extra - Mitochondria,
chromosomal chloroplasts14
DNA for
survival
10
<eu>true bacteria
11
putrefying bacteria
12
some are phytoplankton (eg. cyanobacteria): have chlorophyll, producers in aquatic ecosystems
13
circular shape; developed by chance by mutation; share w friends
❌
if autotrophic:
of cell membrane)
✅
eg. antibiotic resistant gene (resist chemicals secreted by organism like fungi to kill bacteria)
14
chloroplast, chlorophyll (respiration / photosynthesis happen at specific areas
Classification Nomenclature
- systematic way to sort organisms - naming of organisms
into groups accor to common
characteristics
- purpose
- study organisms in a systematic way
- identify an organism more easily by matching it with characteristics of one of
the groups
- understand the phylogeny 1of organisms
- make predictions
- Scientists predict effect of a chemical on a new species based on the
effect on known similar species
- Deduce body structures/functions of an ancestor from features of its
descendents
- Taxonomic hierarchy
- today’s system originated from one made by Carolus Linnaeus2 (18th cent.)
- group organisms with similar characteristics into categories arranged at diff
levels
- share same lower hierarchy level, closer phylogenetic relationship,
more recent common ancestor3
- same group: same fundamental similarities; same subgroup: more
similarities
- kingdom > phylum > class > order > family > genus > species
- species = organisms can interbreed to produce fertile offspring4
- similar structural features + genetic materials
- Nomenclature
- universal scientific name w/ 2 Latin words
- printed: italics; written: underlined separately5
genus name species name
- begin with a CAPITAL LETTER - begin with a small letter
- may be abbreviated in later usage - may suggest who/where it was
T. officinale (Taraxacum officinale) discovered
1
evolutionary history
2
father of taxonomy
3
share same higher hierarchy level, less close phylogenetic relationship, common ancestor in more
4
❌
distant past
mule (horse + donkey) (infertile)
horse 64 chromosomes + donkey 62 chromosomes > mule 63 chromosomes cannot pair up properly
during meiotic cell division to produce normal gametes > infertile
5
❌
mule: Equus asinus x Equus caballas
tilt handwriting
,Modern Classification system
- Ancient Greek - 1960s: based on similarities in structural/morphological features6
- Tech advancement: microscopy
- observe cellular structure
- contain chlorophyll and can swim freely > both plant and
animal characteristics > Protista
- presence of membrane bounded organelles > separate
prokaryote and eukaryote
- diff composition of cell wall > Fungi7
- DNA base sequencing8
- determine nucleotide sequence of DNA of diff organisms
- more similar genetic material > closer phylogenetic relationship
- phylogenetic relationship > separate Archaea and Bacteria,
group 4 eukaryotic kingdoms as Eukarya (3 domains)
- Now: based on phylogenetics9
- 3 domain + 6 kingdoms
- less diff rRNA sequence, more similar genetic materials, closer
phylogenetic relationship
- closer branches in evolutionary tree
3 domains
1. Bacteria
- most are harmless
- important for human
survival
2. Archaea
- more ancient
- @extreme environment
- less understanding
- more closely related to
Eukarya than Bacteria
3. Eukarya
- Plants more closely
related to protista than
fungi
- Fungi more closely
related to animals than
plants
6
7
analogies✅ ❌
external observable
X carry out photosynthesis like plants
physiological (use…for…)
8
OR amino acid sequencing OR comparing mRNA of similar protein > #diff by accumulated mutation
9
homologies
, Kingdom Eubacteria10 (from Domain Bacteria)
- v small: 1-5um long (light microscope: high power)
- diff shapes (3 basic)
- rod-shaped bacillus: Escherichia coli
- Spherical coccus: Streptococcus suis
- Spiral spirillum: Helicobacter pylori cause bleeding of stomach
- Nutrition: heterotrophic (saprophytic11 / parasitic) / autotrophic12
- Motion: motile / non-motile
- Reproduction: by binary fission/spore
- live in a variety of habitat (air, water, soil, inside other organisms)
- important in material cycling in ecosystem
- some can cause diseases to humans, fungi, plant (eg. cholera)
Cell wall Unicellular
- X cellulose, prokaryote
peptidoglycan - X true nucleus
- Bacterial
Cell membrane chromosome
- bacterial / lie free in
eukaryotic cytoplasm
phospholipid circular DNA
bilayer - X membrane
-bounded
Plasmid13 organelles
- extra - Mitochondria,
chromosomal chloroplasts14
DNA for
survival
10
<eu>true bacteria
11
putrefying bacteria
12
some are phytoplankton (eg. cyanobacteria): have chlorophyll, producers in aquatic ecosystems
13
circular shape; developed by chance by mutation; share w friends
❌
if autotrophic:
of cell membrane)
✅
eg. antibiotic resistant gene (resist chemicals secreted by organism like fungi to kill bacteria)
14
chloroplast, chlorophyll (respiration / photosynthesis happen at specific areas
