MICROBIOLOGY EXAM 1 QUESTIONS
WITH COMPLETE ANSWERS|LATEST
UPDATE { GRADED A+}
What would happen if you suddenly removed all microorganisms from earth? - ✔✔- diseases
would be gone
- fermented foods would disappear
- digestion of many foods would be difficult
- vitamins and cofactors would not be produced
- nitrogen fixation would cease
- all photosynthesis would cease within a year
- atmospheric oxygen stores might last decades, but CO2 levels would rise
- biomass would accumulate
ultimately most species would go extinct
What are microorganisms/microbes? - ✔✔a living organism that requires a microscope to see
,- very diverse (morphologically)
- size ranges from 0.2 micrometer to 1 millimeter
- exceptions because larger microbes have been discovered
ex: cyano bacteria, E. coli, stentor (protist), halophilic archea, lichen, zika virus
What factors could determine the maximum or minimum size of a single celled organism? Could
even bigger or smaller ones be discovered? - ✔✔- more may be discovered with exploration of
new environments (many unexplored)
- size needs to be large enough to function
- if cells to large their SA may become too small to transport
Where do microrganisms live? - ✔✔- water, soil, air
- deep in earth
- high in the atmosphere
- in and on all animals and plants
- ex: hydrothermal vent (extremely hot)
What do microorganisms do? - ✔✔- fix the most carbon and all the nitrogen, produce the most
oxygen
- diversity in where they can live, eat, and chemicals they can produce
- some eat toxins, breathe uranium, thrive in hot springs, freezing oceans, or acid mine drains
, - build communities, communicate, cooperate, and prey on each other
- many cause disease, but many more play positive roles in the health of humans and the planet
-paved the way for the evolution of life on earth
Nitrogen fixation - ✔✔- process where bacteria and archea convert N2 (atmospheric nitrogen)
to NH3 (ammonia) or related compounds, which are then taken up by plants
- needed by plants to grow properly
Carbon fixation - ✔✔- process where photosynthetic organisms turn inorganic carbon into
organic carbon
The Great Oxygenation Event - ✔✔- evolution of microbes led to this event
- before photosynthesis the earths atmosphere had no free oxygen
- when microbes evolved they used photosynthesis to produce oxygen
- rapid oxygenation changed evolution; organisms that didnt rely on O2 died
- in stage 2 the O2 did not stay in the environment and was abosorbed by ocean and seabed rock
- stage 3 O2 abosrbed by land
- stage 4 the O2 filled atmosphere
How do bacteria form symbioses? - ✔✔- intimate association between microorganisms of
different species
- bacteria and animal
WITH COMPLETE ANSWERS|LATEST
UPDATE { GRADED A+}
What would happen if you suddenly removed all microorganisms from earth? - ✔✔- diseases
would be gone
- fermented foods would disappear
- digestion of many foods would be difficult
- vitamins and cofactors would not be produced
- nitrogen fixation would cease
- all photosynthesis would cease within a year
- atmospheric oxygen stores might last decades, but CO2 levels would rise
- biomass would accumulate
ultimately most species would go extinct
What are microorganisms/microbes? - ✔✔a living organism that requires a microscope to see
,- very diverse (morphologically)
- size ranges from 0.2 micrometer to 1 millimeter
- exceptions because larger microbes have been discovered
ex: cyano bacteria, E. coli, stentor (protist), halophilic archea, lichen, zika virus
What factors could determine the maximum or minimum size of a single celled organism? Could
even bigger or smaller ones be discovered? - ✔✔- more may be discovered with exploration of
new environments (many unexplored)
- size needs to be large enough to function
- if cells to large their SA may become too small to transport
Where do microrganisms live? - ✔✔- water, soil, air
- deep in earth
- high in the atmosphere
- in and on all animals and plants
- ex: hydrothermal vent (extremely hot)
What do microorganisms do? - ✔✔- fix the most carbon and all the nitrogen, produce the most
oxygen
- diversity in where they can live, eat, and chemicals they can produce
- some eat toxins, breathe uranium, thrive in hot springs, freezing oceans, or acid mine drains
, - build communities, communicate, cooperate, and prey on each other
- many cause disease, but many more play positive roles in the health of humans and the planet
-paved the way for the evolution of life on earth
Nitrogen fixation - ✔✔- process where bacteria and archea convert N2 (atmospheric nitrogen)
to NH3 (ammonia) or related compounds, which are then taken up by plants
- needed by plants to grow properly
Carbon fixation - ✔✔- process where photosynthetic organisms turn inorganic carbon into
organic carbon
The Great Oxygenation Event - ✔✔- evolution of microbes led to this event
- before photosynthesis the earths atmosphere had no free oxygen
- when microbes evolved they used photosynthesis to produce oxygen
- rapid oxygenation changed evolution; organisms that didnt rely on O2 died
- in stage 2 the O2 did not stay in the environment and was abosorbed by ocean and seabed rock
- stage 3 O2 abosrbed by land
- stage 4 the O2 filled atmosphere
How do bacteria form symbioses? - ✔✔- intimate association between microorganisms of
different species
- bacteria and animal
