L3 Marine Microbes

Question 1

What has recorded microbial composition for dacades?

Answer 1

Continuos plankton recorder, Plymouth.

Filters dragged behind boats, with different mesh sizes. Good resource to find out changes over time.

Question 2

What is the most common biological agent in the ocean?

Answer 2

Viruses

Question 3

eg marine virus

Answer 3

CroV - most complex and largest.

Attacks heteroflagellates

Question 4

What is the largest PK?

Answer 4

Thiomargarita 0.75mm

Question 5

Why are PK important in ocean?

Answer 5

Major role as decomposers, recycle DOM
degrade oil spills
Labile sea foam broken down by PK

Question 6

draw the microbial loop

Answer 6

.

Question 7

define:
Endophytes
Epipyhtes
Endolithic

Answer 7

Endophytes- live inside plants
Epipyhtes - Live on plants
Endolithic - Burrrow into rocks

Question 8

What pigment do cyanobacteria use?

Where does ph occur?

Answer 8

Phycocyanin, over Chl a

folded membranes, not chloroplasts

Question 9

What is Trichodesmium?

Answer 9

Most abundant group of cyanobacteria

Question 10

Trichodesmium hotspots..

Answer 10

can be seen from space

N low regions

Question 11

A special cell type in Trichodesmium

Answer 11

Diazocyte - N fixing

inhibited in presence of O2.

Question 12

What is the most abundant photosynthesiser?

Answer 12

Prochloroccus
type of cyanobacteria
very small, <1/2 micrometer

Question 13

What is an issue with N fixing bacteria?

Answer 13

When they die, N sinks with them to lower levels so N at surface must be replenished.

Question 14

What other nutrients does Trichodesmium utilise?

Answer 14

Phosphonates

Phosphates

Question 15

What are Crenarcheota?

Answer 15

Extremophile archaea capable of transforming ammonia

Question 16

What is marine snow?

Answer 16

stream of particles sinking to depth

Bacteria and archaea embedded in marine snow

Question 17

What is another pigment some bacteria use to capture light energy?

Answer 17

Proteorhodopsin

Question 18

3 EK phytoplanktom

Answer 18

Diatoms
Dinoflagellates
Coccolithiphores

Question 19

Which EK phytoplankton migrate to depth daily?

Answer 19

Dinoflagellates, when nutrients depleted in upper layers go down.

Question 20

How do diatoms stay afloat?

Answer 20

Huge extensions of cell aid flotation

Question 21

3 heterotrophic protists

Answer 21

Foraminifera - planktonic and benthic
Radiolaria - siliceous sediment formed from shells when dead
Ciliates - can inhabit guts of sea urchins, fish skin or are planktonic.

Question 22

What is a Tintinnid?

Answer 22

Heterotrophic protist, ciliate

Question 23

What is the claw hypothesis?

Answer 23

There is a homeostatic feedback which balances oceanic phytoplankton and climatic production of DMS

Question 24

What is DMS?

Answer 24

Dimethyl sulphide

Flux from sea to air is important in the biogeochamical sulphur cycle

Question 25

How do algae produce DMS?

Answer 25

algal metabolite DMSP is considered a major precursor to DMS

Question 26

How may symbiosis have evolved?

Answer 26

coevolution of bacteria and hosts. maybe began association by living alongside host and increasing host chances of survival. Over time became so intimate that host couldn't survive without it.

Question 27

example of symbiosis` 3

Answer 27

1. Bacteria in Shipworms digest wood as shipworms lack cellulase. 2. Bioluminescent bacteria are enclosed in photophores . eg Flashlight fish have bioluminescence beneath each eye with shutter mechanism to control emmission of light. 3. Chemosynthetic bacteria are symbiotic with mussels and clams from hydrothermal vents.

Question 28

Why might protozoans be more impressive than animals?

Answer 28

As they are single celled organisms, each cell carries out every function that all the cells in a multicellular animal would carry out.

Question 29

What is a protozoan?

Answer 29

AKA protist Single celled, eukaryotic Not true animals or plants, different kingdom

Question 30

What are 3 protists?

Answer 30

Radiolarians Ciliates Foraminiferans

Question 31

Describe Radiolarians

Answer 31

Elaborate silica skeletons which form radiolarian ooze due to pressure in deep water. Spherical with radiating spines

Question 32

Describe Ciliates

Answer 32

Use cilia for feeding and movement some live on gills of clams, fish skin, sea urchin intestines, or attached to substrate eg Tintinnids, Paramecium.

Question 33

Describe foraminiferans

Answer 33

CaCO3 test with several chambers Retractable pseudopodia (extensions of cytoplasm) protrude through pores in test and trap diatoms. Many benthic, attached to substrate (<5cm) Tests form foraminiferan ooze after death.

Question 34

How can foraminiferans be used to detect changes in temperature?

Answer 34

identify species in glaciers to determine temperatures back in time.

Question 35

How many species of marine fungi are there?

Answer 35

1500, mostly microscopic

Question 36

What ecosystem roles do fungi have?

Answer 36

Important decomposers of cellulose eg mangrove leaves, driftwood, detritus that accumulates in blooms. Nutrient recycling in estuaries. Parasites of seagrass

Question 37

How do fungi affect economy and human life?

Answer 37

Possible source of antibiotics | Cause economically damaging diseases.