10.1 - NOTES = classification
Classification Systems - Process of living organisms are sorted into groups.
- Taxonomic group – KPCOFGS
- Kingdom is biggest and broadest, and species is the smallest and most specific.
- Hierarchical - Linnaean
reasons - Identification = species an organism belong can be easily identified
- Predict characteristics = if several members in group have specific characteristic, likely
that another species group will do too.
- Evolutionary links – species in same group share characteristics as they have evolved
from common ancestor.
- Share research and links can be seen in different habitats.
- Only for observed organisms.
How they're classified - 3 domains = Archaea, Bacteria and Eukarya (broadest)
- End with species and are smallest units (group of organisms that can reproduce to
produce fertile offspring.
naming - Common names aren't same in all languages, and do not provide information about
relationships with other organisms.
- Binomial nomenclature.
- First word is organism's genus (generic name) with capital.
- Second is species (unspecific name) and underlined.
- Could have same specific name but genus is different.
10.2 - NOTES = 5 kingdoms + changes to classification systems
prokaryote - Bacteria
- Unicellular
- No nucleus or membrane bound organelles.
- Plasmids or free-floating DNA/ small ribosomes
- No visible feeding mechanisms – nutrients are absorbed through cell wall or photosynthesis.
Protoctista - Unicellular eukaryotes
- A nucleus and membrane bound organelles.
- May have chloroplast.
- Can be sessile (immobile) or move via cilia or flagella.
- Can be autotrophic – via photosynthesis so they are self-feeding.
- Can be heterotrophic – feed off other organisms.
- Can be both or parasitic.
fungi - Yeasts, moulds and mushrooms
- Multi/Unicellular
- A nucleus and other membrane bound organelles and cell wall (chitin)
- No chloroplast or chlorophyll
- No mechanism for movement
- Most have a body of mycelium of threads and hyphae.
- Nutrients absorbed from decaying material (saprophytic) and can be parasitic.
- Most store their food as glycogen.
plantae - The plants
- Second largest kingdom
- Multicellular
- With nucleus and membrane bound organelles with chloroplast + cell wall with chitin
- All have chlorophyll.
- Most do not move; gametes move with cilia or flagella.
- Nutrients via photosynthesis (autotrophic)
- Store food as starch
animalia - The animals
- Multicellular
- A nucleus and other membrane bound organelles (no cell walls)
- No chloroplast
- Move with cilia, flagella or contractile proteins (can be in form of muscular organs)
- Heterotrophic (depend on organisms)
- Food stored as glycogen.
, Changes to system - Before just on observation but now with genetics and biological molecules – links between
other organisms can be seen.
- As organisms evolve – internal and external features change + DNA.
- DNA determines proteins which determines organism's characteristics.
- So, for change in characteristic their DNA must be changed too.
- Comparing similarities in DNA and proteins of species – you can find relationships between
them.
domain - Woese's system organises groups using differences in sequence of nucleotides in rRNA +
membrane lipid structure and sensitivity to antibiotics.
- 3 domain system – 3 domains + 6 kingdoms (different domains have unique form of rRNA
and different ribosomes)
- Eukarya – 80s ribosomes = RNA polymerase contains 12 proteins
- Archaea – 70s ribosomes = RNA polymerase have 8-10 proteins (similar to eukaryotic
ribosomes)
- Bacteria – 70s ribosomes = RNA polymerase has 5 proteins
Common ancestor -> [bacteria or [[archaea + eukarya]]]
Bacteria -> eubacteria
Archaea -> archaebacteria
Eukarya -> [Protoctista [plantae [fungi [animalia]]]]
archaebacteria - Single celled prokaryotes
- Ancient bacteria
- Can live in extreme environments.
eubacteria - Single celled prokaryotes
- Chemical makeup is different from archaebacteria.
- True bacteria
- In all environments
- Most bacteria are out of eubacteria kingdom.
10.3 - NOTES = phylogeny
phylogeny - Evolutionary relationships between organisms
- Study of evolutionary history of groups of organisms – phylogenetics
- Reveals which group an organism is related to and how closely.
- Classification can occur without knowledge of phylogeny.
Phylogenetic - Diagram to represent evolutionary relationships between organisms.
trees - Branched diagrams to show evolved species with common ancestors.
- Earliest species is found at base and most recent at top.
- Produced by looking at similarities and differences in species physical characteristics and genetic
makeup.
- Evidence gathered from DNA, proteins and fossil records.
Advantages to - Can be done without reference to Linnaean classification.
phylogenetic - Classification uses knowledge of phylogeny for confirmation of classification groups (correct or can
classification be changed)
- Phylogeny produced continuous tree, but classification requires discrete taxonomical groups – if
they do not fit then they are not put there.
- Linnean can be misleading – implied different groups within same rank are equivalent.
10.4 - NOTES = evidence for evolution
evolution - Theory that describes the way in which organisms evolve, change over many years because of
natural selection.
- Darwin realised that organisms best suited to their environment = more likely to survive and
reproduce which passes characteristics to offspring.
- Gradually species change to have more advantageous phenotype for environment it lives in which
is passed onto the following generations (genes in DNA)
Evidence for - Palaeontology – study of fossils and fossil record
evolution - Comparative anatomy – study of similarities and differences between organisms’ anatomy
- Comparative biochemistry – similarities and differences between chemical makeup of organisms
palaeontology - Fossils are formed when animal and plant remain are preserved in rocks, sediment forms and
forms layers of rock (overtime)
- Different layers correspond to different geological eras (more recent layer is found on top)
- Fossil record – fossils found are difference which shows organisms have changed overtime.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller saimabegum. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.49. You're not tied to anything after your purchase.
