topic 1 - classification Flashcards
what are the basic units of life, energy and heredity
cells = life
ATP = energy
DNA = heredity
how did aristotle order organisms, earth, and soul
minerals –> plants –> animals –> humans –> angels –> god
what is the 5 kingdom taxonomic heirarchy based on
similarities and differences in morphology and nutrition
what is the order of the kingdom taxonmoic heirarchy
kingdom - most inclusive
phylum
class
order
family
genus
species - only one organism
what is binomial nomenclature
Genus species (italics)
what are the 5 kingdoms and what are the differences between them
monera - unicellular, no nucleus
protista - mostly unicelluar, nucleus
fungi - multi or unicellular, nucleus (different from plants due to nutrition
plantae - nucleus, photosynthetic, non mobile
animalia - nucleus, mobile, heterotrophic (eats other organisms)
what is the use of rRNA
translate genetic info into proteins
how can rRNA be used to tell relation
more similar nucleic acid sequence = more closely related
- big difference = diverged long ago in evolution
why did we switch to the 3 domain classification system
rely more on genetics (nucleic acid sequence)
- based on similarities and differences in molecular info
what are the 3 domains
bacteria
archaea
eukarya
what is the potential development in the 3 domain system
found that eukarya evolved from archaea (turn into 2 domain system with eukarya as a branch off of archaea)
what are the characteristics of bacteria
prokaryotic - no nucleus
unicellular
cell walls = peptidoglycan (mesh of carbs and proteins)
small - 1-5 um in radius/length
what are the characteristics of archaea
prokaryotic - no nucleus
unicellular
live in high salinity / high temp environments
many dont have a cell wall
soem have cell wall of pseudopeptidoglycan (same function as bacteria but chemmically very different)
what are the characteristics of eukarya
eukaryotic
nucleus
uni/multicellular
soem have cell wall (plants = cellulose, fungi = chitin)
large (10-100x larger than bacteria/archaea)
what are the similarities between eu and prokaryotes
cytoplasm
DNA
cell membrane
ribosomes
what are the differences between eu and prokaryotes
prokaryote
- DNA in cytoplasm
- single circular pieve of DNA condensed in the nucleoid
- lacks membrane bound organelles
- small
eukaryotes
- multiple linear pieces of DNA in nucleus
- endomembrane system
- organelles
- big
what are the 2 reasons prokaryotic cells are small
geometry
diffusion
how does geometry affect prokaryotic cells
every time a cell doubles in size - SA to volume ratio decreases by half
small cells have lots of SA relative to volume
how does diffusion affect prokaryotic cells
smaller SA = nutrients can diffuse right into the middle of the cell - rate of diffusion can support the internal volume
larger SA = nutrients don’t reach the centre in the same amount of time it takes in a small cell
how can eukaryotes be large
- membrane bound organelles
- have endomembrane system (additional membranes = increased SA)
- compartmentalisation of cytosol and transport of nutrients and waste
not solely relying on simple diffusion for molecule transport
what is a vertical gene transfer
gene from parent passed to offspring
what is a horizontal gene transfer
gene from one species becomes part of the genome of another species
bacteria gave rise to chloroplasts and mito from these events
what are symbiotic relationships
occur between 2+ organisms
not always detrimental
common in nature
what are the 3 types of symbiosis
parasitic - benefit one, detrimental to other
commensal - one benefits and the other is neutral
mutual - benefit both
what is the endosymbiotic theory
some eukaryotic organelles were originally independent prokaryotic cells
what is endosymbiosis (long)
- host cell = archaea like prokaryote (energy starved)
- endosymbiont = bacteria like prokaryote (efficient at aerobic resp)
host received - energy (ATP from bacteria)
endosymbiont received - protection and nutrients
host and endo became so dependent on each other that they could no longer be separated
endosymbiont evolved into mito
photosynthetic bacteria evolved into chloroplasts
host cell used excess energy to evolve more complex cell structures and grow
what is the evidence for the endosymbiotic theory
mito and chloroplasts are:
- same size as modern prokaryotes
- have circular DNA
- divide by binary fission (how prokaryotic cells divide)
- have ribosomes more similar to modern bacterial ribosomes
prokaryotic and mito rRNA are more similar than eukaryotic rRNA
phototroph vs chemotroph
phototroph = light eater
chemotroph = chemical (food) eater
autotroph vs heterotroph
autotroph = self eeater (gets carbon from CO2)
heterotroph = other eater (gets carbon from plants/animals/organic molecules)
what is an organism called that gets its carbon from organic sources and energy from organic sources
chemoorganoheterotroph (animals)
what is an organism called that gets its carbon from inorganic sources and energy from organic sources
chemoorganoautotroph
what is an organism called that gets its carbon from inorganic sources and energy from inorganic sources
chemolithoautotroph
what is an organism called that gets its carbon from organic sources and energy from inorganic sources
chemolithoheterotroph
what is an organism called that gets its carbon from organic sources and energy from light sources
photoheterotroph
what is an organism called that gets its carbon from inorganic sources and energy from light sources
photoautotroph (plants)
