Water Flashcards Preview

Microbiology Final > Water > Flashcards

Flashcards in Water Deck (150)
Loading flashcards...
1

The biological activity of an aquatic ecosystem depends on the activity of what?

Primary producers

2

What are 4 examples of primary producers?

oxygenic photoautotrophs, phytoplankton. Algae, Cyanobacteria

3

What is one function of cyanobacteria?

fix nitrogen

4

What organisms serve as a food source for chemoheterotrophs?

bacteria, protozoa, fish, other aquatic organisms.

5

zoo =
phtyo =

- animal
- plant

6

What factors are the activity and net number of phytoplankton dependent on?

Temperature, light received, limiting nutrient availability

7

What limiting nutrients are phytoplankton sensitive to?

Nitrogen, Phosphorus

8

What is the photic zone?

The depth (m) that light will penetrate to in clear water

9

How deep will light penetrate in clear water?

300 m

10

How are microorganisms able to harvest the little amount of light that reaches them?

Via accessory pigments

11

Halotolerant organisms can reach salt levels up to what %?

3%

12

__% of the ocean is deeper than ___ m.

75%, 1000 m.

13

What is the deepest depth of the ocean? What is the pressure here?

11 km below the surface. 1100 atmospheres (~1 atm/ 10 m)

14

At what depth does the temperature of the ocean stay constant? What is the constant temp?

Below 100 m, 2-3 Celcius

15

Synonym for open ocean

Pelagic zone

16

What is very low in the Pelagic Zone? Why?

Primary productivity. Lack of inorganic nutrients (nitrogen, phosphorus, iron) that are required by phytoplankton.

17

The open ocean is __________.

Oligotrophic

18

Oligotrophic

relatively low in plant nutrients and containing abundant oxygen in the deeper parts

19

What is the temperature like in the open ocean compared to shore?

Cooler and more constant

20

How are nutrients brought up to the surface in some regions of the open ocean?

wind and ocean currents cause an upwelling of water from the ocean floor --> promotes productivity

21

What does the majority of primary productivity come from in the open ocean?

prochlorophytes

22

What are prochlorophytes?

Tiny phototrophs phylogenically related to cyanobacteria: Prochlorococcus

23

Two common adaptations observed in pelagic microorganisms?

-Size reduction (high surface/volume ratio)
-High affinity transport systems

24

3 characteristics of Trichodesmium

-Filamentous cyanobacteria
-Contains phycobilins
-Nitrogen fixation

25

What are the two primary producers of coastal waters?

- Algae
- Cyanobacteria

26

Why is productivity usually higher in coastal waters?

Influx of nutrients from rivers and polluted water sources

27

What is an example of a source of influx of nutrients in coastal waters? What nutrients does this provide?

Agricultural runoff. Nitrogen, Phosphorus

28

What is a eutrophic body of water?

Has high biological activity due to excessive nutrients (phosphorus + nitrogen). Becomes dominated by aquatic plants or algae.

29

What might happen at coastal waters (eutrophic body of water)?

Red tides

30

What are 3 characteristics of red tides? Which nutrient is limiting?

Algal bloom, dinoflagellates, neurotoxins. Nitrogen