quiz dec 3

Question 1

What are keystone species?

Answer 1

organisms that play a significant ecological role in the structure and function of an ecosystem

Question 2

what is the biosphere?

Answer 2

enormous system at planetary scale in which all ecosystems are interconnected

Question 3

What is the difference between niche and habitat?

Answer 3

• Habitat: an organism’s physical location. Exactly that area that a species prefers, where it lives
• Niche: an organism’s relationship to food and enemies. The unique position occupied by a species, both in terms of its physical use of its habitat and its function within an ecological community

Question 4

What are the different zones that we define for the study of the marine environment? Which of these are pelagic zones and which benthic zones?

Answer 4

Pelagic zone = open water. Can be: NO
• Neritic zone: near shore over the continental shelf
• Oceanic zone: beyond the continental shelf

Benthic zone = bottom LSBAH
• Littoral zone: intertidal
• Sublittoral zone: beyond the littoral zone 
• Bathyal zone: slopes to great depths
• Abyssal zone: below bathyal zone
• Hadal zone: deepest

Question 5

What is the cycle of matter and energy in an ecosystem?

Answer 5

Dead producers and consumers and their waste products provide matter and energy to decomposers. Decomposers transform matter back into inorganic forms that can be recycled within the ecosystem. So, the energy that enters an ecosystem as sunlight eventually flows out of the ecosystem in the form of heat.

Question 6

what is a landscape?

Answer 6

several ecosystems interacting together

Question 7

What is a microbial loop?

Answer 7

trophic pathway in the marine microbial food web where dissolved organic carbon is returned to higher trophic levels via its incorporation into bacterial biomass, and then coupled with the classic food chain formed by phytoplankton-zooplankton-nekton

Question 8

what do gills do?

Answer 8

extract oxygen

Question 9

red tides?

Answer 9

When dinoflagellates become so numerous that the water becomes red from the accessory pigments.

Question 10

harmful algal blooms?

Answer 10

(HABs): Red tides caused by some dinoflagellate species that synthesize potent toxins as by-products of metabolism

Question 11

What is a major difference between plankton and nekton?

Answer 11

Plankton: drift
Nekton: swim

Question 12

bioaccumulation?

Answer 12

Increase in concentration of a pollutant in an organism

Question 13

zooplankton?

Answer 13

planktonic organisms that eat other plankton (large cyanobacteria, diatoms, dinoflagellates, etc.) composed mainly of small microflagellates and microcilliates (tiny protistans). Most numerous primary consumers of the ocean. Their mass is about 10 % of that of the phytoplankton. Copepods (tiny crustaceans): 70% of the zooplankton, Giant jellyfish, Krill, etc. Holoplankton: members of the plankton that spend their whole life cycle in the plankton community. Meroplankton: members of the plankton that spend only a part of their life cycle in the plankton, and will later adopt benthic or nektonic lifestyle

Question 14

diatoms?

Answer 14

single-celled algae, extremely efficient at photosynthesis, protected by a frustule (rigid cell wall composed of 2 valves) made with silica (SiO2). Almost the most productive photosynthetic organisms.

Question 15

How big are picoplanktonic organisms?

Answer 15

very small (0.2-2 micrometers) producers in the phytoplankton, mainly forms of cyanobacteria (photosynthetic bacteria). May account for up to 80 % photosynthesis in some parts of the ocean

Question 16

Why is zooplankton’s mass 10% of that of the phytoplankton?

Answer 16

The biomass of zooplanktons is higher than that of phytoplankton because zooplanktons have a low weight and are smaller in size. They furthermore live in the depths of water bodies away from sunlight and swim to the surface to feed on phytoplankton during the night time.

Question 17

Where are nutrient levels the highest? and why

Answer 17

Near by the continents because of the upwellings

Question 18

Phytoplankton?

Answer 18

autotrophic plankton composed of single-celled (mostly) plantlike organisms lacking a common ancestor that are unable to laterally move through the ocean. They generate large amounts of O2.

Question 19

nektonic animals?

Answer 19

Most are vertebrates: Fishes, reptiles, and marine birds and mammals. Some are invertebrates: Squid, nautiluses and octopuses. More species of fishes (about 32000 species), and more individuals, than species and individuals of all other vertebrates combined

Question 20

dinoflagellates?

Answer 20

Single-celled autotrophs with a protective cellulose cover and 2 flagella they use to move. Majority have free life. Some species (zooxanthellae) live inside the tissues of corals

Question 21

pelagic organisms?

Answer 21

organisms that live suspended in the column of water. They have a great variation in their forms and have problems to keep their vertical position, producing or obtaining food and for surviving and reproduce

Question 22

plankton?

Answer 22

pelagic organisms drift with ocean currents.

Question 23

nekton?

Answer 23

organisms that actively swim

Question 24

biome

Answer 24

an area of similar climate where a cluster of species is distributed throughout (terrestrial)

Question 25

competition

Answer 25

Interactions where both species are harmed. Occurs over resources. Can be intraspecific (same species) or interspecific (diff species)