Quiz #1 General Knowledge

Question 1

the oceans - percentages

Answer 1

• 71% of Earth’s surface
• 90% of biosphere
• 50% of primary production

Question 2

size classes

Answer 2

femto (0.01-0.2 microns)
pico (0.2-2 microns)
nano (2-20 microns)
micro (20-200 microns)
(all prefixes go before "plankton")

Question 3

coriolis effect

Answer 3

• currents are deflected to the right in the northern hemisphere and the left in the southern
• helps shape gyres

Question 4

importance of circulation

Answer 4

-creates distinct ecological environments (niches) of different temperatures, nutrients, etc.

Question 5

light

Answer 5

• energy for phototrophs and heat

- angle of incidence varies with latitude and season

Question 6

Major elements of marine life

Answer 6

• nitrogen (proteins, DNA/RNA)
• phosphorous (DNA/RNA)
• carbon (lipids, proteins, carbs)
• silicon (SiO2: silica frustules)

Question 7

iron

Answer 7

• insoluble in seawater
• essential but occurs in trace amounts
• introduced by weathering/dust
• HNLC zones are limited by iron

Question 8

IronEx

Answer 8

• experimental addition of iron to HNLC zones to see if it would cause great phytoplankton growth
• it did

Question 9

net tows

Answer 9

• Used to collect cells using a fine mesh net dragged through the water (bigger microbes)
• sample the water column

Question 10

grab sampler

Answer 10

• sample the sediment
• doesn’t preserve the layers
• like a claw machine

Question 11

corer

Answer 11

• sample the sediments
• layers represent depth below sea floor
• preserves layers

Question 12

manned submersibles

Answer 12

• sample deep sea

- EX: Alvin

Question 13

autonomous undersea vehicle (AUV)

Answer 13

-sample deep sea

Question 14

the environmental sample processor

Answer 14

• designed for autonomous, remote sample collection and processing
• designed for shipboard and subsurface in situ applications

Question 15

enrichment

Answer 15

• culture dependent
• duplicate as closely as possible a particular environment (light, temperature, salinity, pressure, etc.)
• design growth medium to enrich for a particular type of organism and exclude others
• EX: grow on media with and without NH4+ to see if the organism can fix nitrogen (will still grow as well as w/ nitrogen if it can)

Question 16

counting/isolation techniques

Answer 16

• agar or silica gel plates or tubes (spread, streak, pour)
• fluorescence activated cell sorter (FACS)
• dilution methods

Question 17

spread plate

Answer 17

-leads to surface colonies only

Question 18

pour plate

Answer 18

• surface and subsurface colonies

- better for culturing some strains because being fully surrounded by media can be a better representation of seawater

Question 19

dilution series

Answer 19

-plate different amounts of the sample on several plates to find the optimal dilution for counting

Question 20

limitations

Answer 20

• Most fit organism for a particular set of chosen conditions becomes dominant although it may have been a minor component of the original community (Remedy: dilute inoculum, then enrich)
• Difficulty of duplicating natural environment in the laboratory

Question 21

direct counts

Answer 21

• microscope
• cells made fluorescent with dye
• cells are naturally autofluorescent

Question 22

major parameters for fluorescent cells

Answer 22

• excitation wavelength
• emission wavelength

-determined by light source and microscope filters

Question 23

16s rRNA

Answer 23

• Universally distributed (all prokaryotes)
• Some regions are highly conserved (allow isolation of this molecule from others)
• Some regions have more variability (distinguish ones organism from another)
• Large database

Question 24

signature sequences

Answer 24

• short stretches of oligonucleotides unique to certain groups of organisms
• Because of their exclusivity they can be used to design phylogenetic probes
• Universal primers

Question 25

archaea

Answer 25

• low prevalence at surface, so assumed to be unimportant in marine microbio
• there is a depth where they are as prevalent as bacteria
• ~1/2 of cells in ocean

Question 26

Environmental DNA Clone Bank

Answer 26

• 1 16S gene/plasmid
• 1 unique plasmid/colony
• using plasmids to clone DNA
• Sequence each plasmid

Question 27

secondary antibodies

Answer 27

• for detecting protein markers of an enzyme’s activity
• label with fluorescent dye, will attach to the antibodies defending against an antigen
• can be highly specific but need to purify antigens and create antibodies

Question 28

isotopes

Answer 28

-forms of an element that differ in atomic weight (differ in the number of neutrons)

Question 29

MAR

Answer 29

• microautoradiography
• can help identify cells that are missed with other techniques
• tracks metabolic activity

Question 30

how are genomes from a single organism sequenced

Answer 30

-assembled from many fragments by aligning sections that are the same

Question 31

ecogenomics

Answer 31

-more difficult to piece together fragments of DNA in real world because many different species present

Question 32

annotation

Answer 32

• converting DNA sequences into potential genes
• assigning function (compare to other proteins/ databases about proteins)
• mostly done by machine, humans still need to check and resolve errors