Lab Week 2: Microscopy & Prokaryotes

which domains contain prokaryotes?

bacteria and archaea

Which kingdom is contained in the domain bacteria?

eubacteria

which kingdom is contained in the domain archaea?

archaebacteria

which kingdoms are contained in the domain eukarya?

protista, plantae, anamalia, fungi

characteristics of archaea

aka extremophiles, prokaryotes that are found in environments that are “extreme”; salt flats, deep sea vents, hot springs, etc.

characteristics of bacteria

domain: bacteria, kingdom: eubacteria

prokaryotic and unicellular

defining feature is peptidoglycan in the cell wall, mostly heterotrophic (some autotrophs: cyanobacteria)

what are the possible morphologies for bacteria cells?

bacilli (rod-shaped), cocci (spherical), spirilli (spiral-shaped)

what are the possible arrangements of bacteria?

coccus, diplococci, staphylococci, streptococci, sarcina, tetrad

Gram positive stain

stains purple

Gram negative stain

stains red/pink

what determines if bacteria is Gram positive or Gram negative?

the position of peptidoglycan in the cell wall

characteristics of cyanobacteria

aka blue-green algae

gram negative bacteria, autotrophs (photosynthetic)

phycobilin: the pigment that gives the blue-green color

three types of cyanobacteria

anabaena, oscillatoria, merismopedia

what is the biological importance of cyanobacteria?

responsible for an oxygen-rich atmosphere, nitrogen fixation, rapid reproduction (noxious bloom forming), produce toxins, high levels of proteins (nutritious)

characteristics of anabaena

colony shape: filamentous

cell types: vegetative (barrel-shaped cells), heterocyst (for N fixation, clear, large, round), akinete (densely packed with spore-like reproductive cells; larger and oval)

what is a symbiotic relationship of anabaena?

azolla (water/mosquito fern) and anabaena (cyanobacteria)

the cyanobacteria lives in the water near the roots of the mosquito fern

characteristics of oscillatoria

“oscillate”, colony shape (filamentous, protected by mucilaginous sheaths)

cell types: trichomes (vegetative), hormogonia formed by necrotic discs (asexual reproduction via fragmentation)

characteristics of merismopedia

colony shape: mat-forming encased in gelatinous matrix

symbiotic relationship of cyanobacteria with plants

nitrogen is essential for plants, plants cannot use nitrogen from the air (N2), rely on nitrogen fixation by bacteria (turn N2 into NH3)