MICROBES EXAM 1 EEMB 3 UCSB
COMPLETE QUESTIONS WITH CORRECT
ANSWERS 2026
Human microbial system - CORRECT ANSWER --is 50% non-human by cell count
-microbes help with skin barrier defense
-alimentary normal flora
-helps us digest food
-help us fight pathogens
-provide vitamins
-every persons microbiome is distinctly different
Microbes - CORRECT ANSWER --90% are benign or beneficial to us
-10^31 viral particles on planet = more viruses than starts in universe
-life force of our planet: dominate energy flow of planet, govern biochemical nutrient spaces
-transform organic and inorganic nutrients
Organic compound - CORRECT ANSWER -a compound that contains carbon-carbon and carbon-
hydrogen bonds; produced by life
Dynamics of energy in ecosystem - CORRECT ANSWER -there is a one way flow of energy
through an ecosystem: light to heat; <-- one of two emergent properties of ecosystem; most
energy comes into ecosystem through light
Dynamics of chemical nutrients in ecosystem - CORRECT ANSWER -chemicals cycle within
ecosystem; demineralization of decomposing and breaking down organic matter back into
organic constituents
,Aquatic ecosystem - CORRECT ANSWER -An ecosystem that is located in bodies of water; 97.5%
salt water and 2.5% is fresh; 71% earth surface occupied by water; total volume is
1.4x10^7km^3 = lots of living space; 300x more space for life than on land or fresh water
Aquatic microbes - CORRECT ANSWER -bacteria, archaea, protists, fungi, viruses; whole lot of
bacteria in there
Photosynthetic microbes - CORRECT ANSWER -phytoplankton take light energy and fix co2 to
organic matter fueling food webs and metabolic processes; The concentration of chlorophyll is
an indicator for the amount of photosynthetic plankton in ocean
Gaia hypothesis - CORRECT ANSWER -earth is a living entity(superorganism) and its biosphere
regulates and maintains climate and atmosphere at an optimum
James Lovelock - CORRECT ANSWER -Englishman who proposed the Gaia hypothesis (the Earth
functions as a kind of superorganism)
Chemical equilibrium - CORRECT ANSWER -state at which chemical reactions and reactants and
products no longer change in time
Chemical disequilibrium - CORRECT ANSWER -the long-term coexistence of two or more
incompatible chemical species
Gaia hyp w/chemical equilibrium example - CORRECT ANSWER -the presence of ch4 and o2
should react, but are both in earth's atmosphere, indicating biogenic sources of theses gases;
could support a living planet
, Earth evolution - CORRECT ANSWER -early earth = very violent place; earth 4.5 bya; oldest rock
3.8-5 bya (cooled down where water could start to form and accumulate, leading to life); oceans
3.8 bya; microfossils 3.5-3.8 bya
Chemistry of life in h2o - CORRECT ANSWER -need water to survive and generate life functions;
polar covalent bonds result in hydrogen bonds; 4 properties of water; photosystem 2 water split
allows energy to be derived
4 properties of water: cohesion and surface tension - CORRECT ANSWER -water "sticks" to itself;
adhesive
4 properties of water: high specific heat - CORRECT ANSWER -very important for heat
regulation; takes a lot of heat to raise temperature of water; can retain + hold heat and
evaporate + cool down
4 properties of water: ice floats - CORRECT ANSWER -water molecules into rigid form; less dense
rising to top; anything beneath ice gets thermal barrier to extreme conditions above ice (think
Arctic, life below ice in ocean)
4 properties of water: versatile solvent - CORRECT ANSWER -lots of things will dissolve in water
Origin of water on earth - CORRECT ANSWER -3 hypothesis (truth is probably combo of all 3):
degassing and condensation + comet impact hypothesis (bring ice to earth) + asteroid impact
hypothesis(h2o inside asteroid brought to earth)
Deuterium to hydrogen ratio - CORRECT ANSWER -allows scientists to compare potential
sources of water; can show how atmosphere changes over time
Cell - CORRECT ANSWER -bag of water containing a bunch of interacting molecules to make
energy
COMPLETE QUESTIONS WITH CORRECT
ANSWERS 2026
Human microbial system - CORRECT ANSWER --is 50% non-human by cell count
-microbes help with skin barrier defense
-alimentary normal flora
-helps us digest food
-help us fight pathogens
-provide vitamins
-every persons microbiome is distinctly different
Microbes - CORRECT ANSWER --90% are benign or beneficial to us
-10^31 viral particles on planet = more viruses than starts in universe
-life force of our planet: dominate energy flow of planet, govern biochemical nutrient spaces
-transform organic and inorganic nutrients
Organic compound - CORRECT ANSWER -a compound that contains carbon-carbon and carbon-
hydrogen bonds; produced by life
Dynamics of energy in ecosystem - CORRECT ANSWER -there is a one way flow of energy
through an ecosystem: light to heat; <-- one of two emergent properties of ecosystem; most
energy comes into ecosystem through light
Dynamics of chemical nutrients in ecosystem - CORRECT ANSWER -chemicals cycle within
ecosystem; demineralization of decomposing and breaking down organic matter back into
organic constituents
,Aquatic ecosystem - CORRECT ANSWER -An ecosystem that is located in bodies of water; 97.5%
salt water and 2.5% is fresh; 71% earth surface occupied by water; total volume is
1.4x10^7km^3 = lots of living space; 300x more space for life than on land or fresh water
Aquatic microbes - CORRECT ANSWER -bacteria, archaea, protists, fungi, viruses; whole lot of
bacteria in there
Photosynthetic microbes - CORRECT ANSWER -phytoplankton take light energy and fix co2 to
organic matter fueling food webs and metabolic processes; The concentration of chlorophyll is
an indicator for the amount of photosynthetic plankton in ocean
Gaia hypothesis - CORRECT ANSWER -earth is a living entity(superorganism) and its biosphere
regulates and maintains climate and atmosphere at an optimum
James Lovelock - CORRECT ANSWER -Englishman who proposed the Gaia hypothesis (the Earth
functions as a kind of superorganism)
Chemical equilibrium - CORRECT ANSWER -state at which chemical reactions and reactants and
products no longer change in time
Chemical disequilibrium - CORRECT ANSWER -the long-term coexistence of two or more
incompatible chemical species
Gaia hyp w/chemical equilibrium example - CORRECT ANSWER -the presence of ch4 and o2
should react, but are both in earth's atmosphere, indicating biogenic sources of theses gases;
could support a living planet
, Earth evolution - CORRECT ANSWER -early earth = very violent place; earth 4.5 bya; oldest rock
3.8-5 bya (cooled down where water could start to form and accumulate, leading to life); oceans
3.8 bya; microfossils 3.5-3.8 bya
Chemistry of life in h2o - CORRECT ANSWER -need water to survive and generate life functions;
polar covalent bonds result in hydrogen bonds; 4 properties of water; photosystem 2 water split
allows energy to be derived
4 properties of water: cohesion and surface tension - CORRECT ANSWER -water "sticks" to itself;
adhesive
4 properties of water: high specific heat - CORRECT ANSWER -very important for heat
regulation; takes a lot of heat to raise temperature of water; can retain + hold heat and
evaporate + cool down
4 properties of water: ice floats - CORRECT ANSWER -water molecules into rigid form; less dense
rising to top; anything beneath ice gets thermal barrier to extreme conditions above ice (think
Arctic, life below ice in ocean)
4 properties of water: versatile solvent - CORRECT ANSWER -lots of things will dissolve in water
Origin of water on earth - CORRECT ANSWER -3 hypothesis (truth is probably combo of all 3):
degassing and condensation + comet impact hypothesis (bring ice to earth) + asteroid impact
hypothesis(h2o inside asteroid brought to earth)
Deuterium to hydrogen ratio - CORRECT ANSWER -allows scientists to compare potential
sources of water; can show how atmosphere changes over time
Cell - CORRECT ANSWER -bag of water containing a bunch of interacting molecules to make
energy
