2.2 communities and ecosystems Flashcards
1
Q
community
A
- a group of populations living and interacting with each other in a common habitat
- only biotic factors
2
Q
primary producers
A
- convert inorganic compounds into food
- obtain their food by making it themselves, autotroph
- base of the food chain
- majority are green plants
- provide food for all other life on earth
- regulate the hydrological cycle through transpiration
- maintain the balance of gases in the atmosphere by absorbing co2 and releasing oxygen
- provides habitats for many animals
- roots bind soil to reduce erosion
3
Q
consumers
A
- can’t make their own food, heterotrophs
- obtain food by consuming other organisms
4
Q
detritivores and decomposers
A
- obtain their energy and nutrients from dead plant animal material and waste
- detritivores
consume detritus to gain nutrients, pass them through their bodies for decomposers
millipedes, woodlice, worms - decomposers
absorb and metabolize waste, release it as inorganic chemicals
bacteria and fungi
5
Q
purpose of detritivores and decomposers
A
- clear ecosystems of dead bodies
- prevent spread of disease from dead bodies
- released nutrients that were locked in organic matter
6
Q
photosynthesis
A
- energy from sunlight is trapped by chlorophyll in green leaves
- co2 is taken in by plant leaves
- h20 is taken up by the plant roots
- glucose is stored as starch
- 02 released
carbon dioxide + water –light– > glucose + oxygen
7
Q
respiration
A
- reversal of photosynthesis
- oxidation of glucose to release energy
- chemical energy into kinetic
glucose + oxygen –oxidation–> carbon dioxide + water + energy
8
Q
trophic level
A
- position an organism/group of organisms occupies in a food chain
9
Q
energy in the food chain
first law
A
- light energy enters the food chain from the sun
- primary producers transform light into chemical energy
- chemical energy transfers along the food chain in biomass
- some energy lost as heat, dissipates into the surrounding environment
10
Q
energy in the food chain
second law
A
- light energy, low entropy
- light energy into chemical increases entropy
- further along the food chain more entropy as energy less efficient
11
Q
ecological pyramid
A
- trophic levels in the same order
- flow of energy up through the pyramid
12
Q
pyramid of numbers
A
- number of organisms at each trophic level in the food chain
- non destructive method of data collection
- can compare changes over time
- all organisms regardless of size
- hard to be accurate
- doesn’t allow for juveniles, can look different
13
Q
pyramid of biomass
A
- what mass is there at that time
- measured as dry weight, no variation in water content
- overcome problems of counting
- measuring body parts not contributing energy such as skeletons/beaks
- samples extrapolated, inaccuracy
- destructive, unethical
- seasonal variation of ecosystems
- some animals store energy as fat, higher energy than those that store as carbs
14
Q
pyramid of productivity
A
- rate of flow of biomass/energy
- most accurate
- ecosystems can be compared
- solar input can be added
- data collection is not easy
- hard to assign specific species to a trophic level
15
Q
biomagnification
A
- increase in the concentration of a pollutant in an organism as it absorbs or ingests from it’s environment
