quiz dec 3 Flashcards
What are keystone species?
organisms that play a significant ecological role in the structure and function of an ecosystem
what is the biosphere?
enormous system at planetary scale in which all ecosystems are interconnected
What is the difference between niche and habitat?
- 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
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?
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
What is the cycle of matter and energy in an ecosystem?
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.
what is a landscape?
several ecosystems interacting together
What is a microbial loop?
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
what do gills do?
extract oxygen
red tides?
When dinoflagellates become so numerous that the water becomes red from the accessory pigments.
harmful algal blooms?
(HABs): Red tides caused by some dinoflagellate species that synthesize potent toxins as by-products of metabolism
What is a major difference between plankton and nekton?
Plankton: drift
Nekton: swim
bioaccumulation?
Increase in concentration of a pollutant in an organism
zooplankton?
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
diatoms?
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.
How big are picoplanktonic organisms?
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
Why is zooplankton’s mass 10% of that of the phytoplankton?
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.
Where are nutrient levels the highest? and why
Near by the continents because of the upwellings
Phytoplankton?
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.
nektonic animals?
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
dinoflagellates?
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
pelagic organisms?
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
plankton?
pelagic organisms drift with ocean currents.
nekton?
organisms that actively swim
biome
an area of similar climate where a cluster of species is distributed throughout (terrestrial)
competition
Interactions where both species are harmed. Occurs over resources. Can be intraspecific (same species) or interspecific (diff species)
