Ecology Flashcards
What is an ecosystem?
interaction between biotic and abiotic communities
What is a biome?
- ecosystem within a specific geographical region
Where does evolutionary origin of plants and animals trace to?
the seas
- they must colonize land and adapt to
- – lack of water, food, varying temperatures, varying composition of soils
What are the 8 terrestrial biomes? (in order from equator to poles)
- desert
- grassland
- rainforest
- temperate deciduous
- temperate coniferous
- taiga
- tundra
- polar
Desert Biome
- very little rain
Grassland biome
- low rainfall
- no shelter for herbivores
- long legged and hooved animals
- prairies
Rainforest biome
- jungles, torrential rainforests (lots of rain)
- temperate vs tropical (tropical high temp)
- dense vegetation
- epiphytes (plants grow on each other) and saprophytes (live off dead matter)
Temperate deciduous forest
- cold winters, warm summers, moderate rain
Temperate coniferous forest
- cold, dry
- beavers, bears, conifers
Taiga
- long, cold winters
- thin soil
- coniferous trees
- extreme northern Canada and Russia
Tundra
- treeless
- frozen plain
- permafrost (covered ground with snow and ice)
Polar region
- polar ice caps
- no vegetation
Marine Biomes
- nutrient materials and dissolved salts
- ocean conditions are more uniform than land
Marine Biome Zones
- intertidal zone: low tides that undergoes variations in temperature and dryness
Necritic Zone
- part of continental shelf that contains ocean with 600 ft deep
Pelagic Zone
- open ocean
Photic and Aphotic Zone
Photic: sun lit
Aphotic: no sunlight, no photosynthesis (nekton and benthos)
Freshwater biomes
- rivers, lakes, ponds, marshes etc
- currents exist! therefore need muscle/holdfasts
- variations in climate and water (freeze/dry up)
What is usable nitrogen in the form of?
nitrAtes
- converted from elemental nitrogen (which is inert) to nitrAte via
nitrogen fixing bacteria and lightning
Usable nitrAtes travel through the nitrogen cycle … describe the pathway.
- Nitrates are absorbed by plants
- proteins produced
- animals eat the proteins
What is nitrate converted to in the nitrogen cycle?
Ammonia (NH3) is released by bacteria of decay.
Nitrogen (as nitrate) locked up in dead plants/animal proteins converted to ammonia
What are the fates of ammonia?
- nitrified to nitrItes
- denitrified / broken down to free nitrogen
What are nitrites used for?
- chemosynthetic bacteria: breaks down ammonia to nitrite and further broken down to nitrAte and absorbed by green plants (cycle happens again)
Explain the process of the carbon cycle:
- plants use gaseous CO2 to produce glucose
- animals eat plants and use the digested nutrients to form carbs, fats, proteins etc
- CO2 is metabolically produced CO2 and released back to the air
Symbiosis:
- live together in association and may or may not be beneficial to participants
Cooperation:
species and embers of same species must cooperate; protect each other and acquire resources
What is external fertilization and is it sexual or asexual reproduction?
asexual reproduction
- fusion of female and male gametes when female deposits her eggs and male gametes fertilize somewhere in the environment
What is double fertilization and where does it occur in?
- union of two sperm cells with two cells of the embryo sac
- occurs in MOSTLY angiosperms and some gymnosperms
