Block A 1

Question 1

3 things that microorganisms are involved in

Answer 1

-production of food and drinks
-decomposition of organic matter
-maintenance of earth’s ecosystems

Question 2

oldest known microorganism and age

Answer 2

fossilised stromatolites
3.5 billion years old

Question 3

estimated mass of bacteria on earth

Answer 3

5x10^30 grams

Question 4

where are most of the estimated biomass found

Answer 4

soil and oceans

Question 5

what is the carbon cycle

Answer 5

decomposition of organic matter releases CO2 through respiration
also plays role in formation of fossil fuels by converting dead plant and animal material into hydrocarbons

Question 6

what is the nitrogen cycle

Answer 6

convert N2 into forms plants and animals can use, eg ammonia (NH3), nitrite (NO2-), and nitrate (NO3-)

Question 7

what is the name given to the process used in the nitrogen cycle

Answer 7

nitrogen fixation
essential for growth of plants and survival of many organisms

Question 8

what is the sulfur cycle

Answer 8

oxidisation of sulfur compounds (eg hydrogen sulphide (H2S)) and conversion into sulfuric acid (H2SO4)

Question 9

what does the sulfur cycle play a role in

Answer 9

geochemical cycling of sulfur and formation of sulfur minerals

Question 10

what is the phosphorus cycle

Answer 10

release of phosphate from minerals, an essential nutrient for plants and animals

Question 11

what does the phosphorus cycle play a role in

Answer 11

formation of bone and teeth
by converting phosphates into hydroxyapatite

Question 12

what is the iron cycle

Answer 12

oxidisation of iron compounds (ferrous iron) and conversion into ferric iron

Question 13

what does the iron cycle play a role in

Answer 13

geochemical cycling of iron and the formation of iron minerals

Question 14

what organism survives at high temps

Answer 14

thermophiles and hyperthermophiles
176°F (80°C) and higher
volcanic hot springs, geysers, and deep sea hydrothermal vents

Question 15

what organism survives at low temps

Answer 15

psychrophiles
-112°F (-80°C) polar ice, permafrost

Question 16

what organism survives at high pressures

Answer 16

piezophiles
1800x atmospheric pressure
deep sea hydrothermal vents and subsurface oil reservoirs

Question 17

what organism survives at high salinities

Answer 17

halophiles
salt flats and salt mines

Question 18

what organism survives at high radiation

Answer 18

deinococcus radiodurans
nuclear waste sites, space

Question 19

what organism survives at high acidity

Answer 19

acidophiles
acid mine drainage, acid hot springs, acid soils

Question 20

why do plants require microbes to survive

Answer 20

microbial symbionts (rhizobia) which live in their roots convert atmospheric N2 into a form that plants can use and is essential for growth of plants (nitrogen fixation)

Question 21

why do animals require microbes to survive

Answer 21

microorganisms digest their food
eg ruminant microbes break down plant materiak and termite microbes digest wood

Question 22

why do animals require microbes to survive

Answer 22

microorganisms digest their food
eg ruminant microbes break down plant materiak and termite microbes digest wood

Question 23

why do humans require microbes to survive

Answer 23

gut microbiome is important for digestion, metabolism, immunity, and production of vitamins and other essential compounds

Question 24

why does marine life require microbes to survive

Answer 24

responsible for primary production
the process of converting dissolved inorganic compounds into organic compounds, which forms the base of the ocean food web

Question 25

why does soil require microbes to survive

Answer 25

break down dead plants and animals, releasing nutrients back into soil help maintain soil structure by forming microbial aggregates that help to retain water and air

Question 26

structure of prokaryotes

Answer 26

no membrane enclosed organelles no nucleus generally smaller than eukaryotic cells

Question 27

structure of eukaryotes

Answer 27

DNA enclosed in a membrane bound nucleus cells are generally larger and more complex contain organelles

Question 28

eukaryotic DNA

Answer 28

linear and found within nucleus usually more than one chr typically 2 copies of each chr

Question 29

prokaryotic DNA

Answer 29

single circular DNA mol called chromosome also may have small amounts of extrachromosomal DNA called plasmids (may confer special properties, antibiotic resistance)

Question 30

what is a genome

Answer 30

a cell's full complement of genes

Question 31

E.coli genome compared with the human cell

Answer 31

-e coli 4.64 mil base pairs 4300 genes -human cell 1000X more DNA per cell than E coli 7X more genes than E.coli

Question 32

what is metabolism

Answer 32

chemical transformation of nutrients

Question 33

what is reproduction

Answer 33

generation of two cells from one

Question 34

what is differentiation

Answer 34

synthesis of new substances or structures that modify the cell (only in some microbes)

Question 35

what is communication

Answer 35

generation of, and response to, chemical signals (only in some microbes)

Question 36

what is movement

Answer 36

via self propulsion, many forms in microbes

Question 37

what is evolution

Answer 37

the process of change over time that results in new varieties and species of organisms

Question 38

what is phylogeny

Answer 38

evolutionary relationships between organisms relationships can be deduced by comparing genetic info in the different specimens relationships visualized on a phylogenetic tree

Question 39

what type of RNA is excellent for determining phylogeny

Answer 39

rRNA

Question 40

comparative rRNA sequencing has defined 3 distinct lineages of cells called domains, what are they

Answer 40

bacteria (prokaryotic) archaea (prokaryotic) eukarya (eukaryotic)

Question 41

what 2 are more closely related (bacteria, archaea, or eukarya)

Answer 41

archaea are more closely related to eukarya than bacteria

Question 42

what are microbial communities

Answer 42

microorganisms exist in nature in populations of interacting assemblages

Question 43

what does habitat mean

Answer 43

environment in which a microbial population lives in

Question 44

what is an ecosystem

Answer 44

refers to all living organisms plus physical and chemical constituents of their environment

Question 45

what is the study of microbial ecology

Answer 45

study of microbes in their natural environment

Question 46

what is the diversity and abundances of microbes controlled by

Answer 46

resources (nutrients) and environmental conditions (temp, pH, O2)

Question 47

what can the activities of microbial communities affect

Answer 47

the chemical and physical properties of their habitiats

Question 48

what are extremophiles and what environments do they grow in

Answer 48

bacteria and archaea -very hot or very cold -very acidic or very caustic -very salty or osmotically stressing -very high pressure

Question 49

where are most microbial cells found

Answer 49

oceanic and terrestrial subsurfaces

Question 50

cells are key reservoirs of what essential nutrients

Answer 50

C, P, N

Question 51

positive impacts of microorganisms and agriculture

Answer 51

N-fixing bacteria cellulose degrading microbes in the rumen regeneration of nutrients in soil and water

Question 52

negative impacts of microoganisms and agriculture

Answer 52

disease in plants and animals

Question 53

negative impacts of microorganisms and food

Answer 53

cause food spoilage, methods of preservation are needed

Question 54

positive impacts of microorganisms and food

Answer 54

fermentation cheeses, yogurt, buttermilk beer, leavened breads etc

Question 55

microorganisms, energy, and the environment

Answer 55

role of microbes in production of biofuels eg methane, ethanol, hydrogen role of microbes in cleaning up pollutants (bioremediation)

Question 56

what did pastuer discover

Answer 56

-living organisms discriminate between optical isomers -alcoholic fermentation was a biologically mediated process -theory of spontaneous generation leading to development of methods for controlling growth of microorganisms

Question 57

what did koch discover