Ecology Flashcards
1
Q
Define ecology
A
- study of interactions of organisms
- with one another
- with environment
2
Q
Abiotic environment
A
- physical factors
- light intensity, water availability, soil pH
3
Q
Biotic environment
A
- living things that organisms interact with
- populations in community live interdependently
- a change in one population would affect other populations
- includes decomposers e.g fungi, bacteria,
4
Q
Define habitat
A
- plc where organism live
- e.g. freshwater stream, forest, grassland, mangrove
5
Q
Define population
A
- grp of organisms of same species
- living tgt in particular habitat
6
Q
Define community
A
- populations of organisms living and interacting with each other
- particular habitat
7
Q
Define ecosystem
A
- community of organisms interacting with one another
- and abiotic environment
8
Q
Physical features of abiotic environment
A
- Light intensity
- Temperature
- Water availability
- Oxygen content
- Salinity of soil, water
- pH of soil, water
9
Q
How do physical features affect surrounding organisms
A
- growth of certain plants affects distribution of animals in location
- organisms found in region usually adapted to physical features of their environment
10
Q
Light intensity
A
- affects rate of photosynthesis, distribution and growth of plants and animals
- green plants only grow in adequate amt of sunlight
- animals depend directly or indirectly on distribution of plants
11
Q
Temperature
A
- affects rate of reaction of enzymes
- that control physiological and metabolic activities of organisms
- e.g. snakes hibernates in winter, less active as enzymatic rxn in body slower due to cold temp
12
Q
Water availability
A
- amt and pattern of rainfall
- air humidity
- water is main component of protoplasm
- in environment where water is scarce, organisms adapted for survival
- desert rat have longer loops of Henle for grate re absorption
13
Q
Oxygen
A
- needed for aerobic respiration to produce energy for cell activities
- e.g mangrove plant roots have pneumatophores to ensure they get enough oxygen
- breathing roots projected above mud surface
- pores for gaseous exchange
14
Q
Salinity
A
- refers to salt conc in water
- affects wp
- affects movement of salt and water in and out of cells or aquatic organisms
15
Q
pH
A
- acidity or alkalinity of a sln
- most organisms can only survive within a range of opt pH
- pH affects rate of enzyme reactions
16
Q
Producers
A
- anything that is able to convert carbon compounds to glucose
- contain chlorophyll, convert light to chemical energy
- all food chains start with producers
- green plants, photosynthetic bacteria
17
Q
Consumers
A
- unable to make food themselves
- obtain food and nutrients by feeding on other organisms
- primary, secondary, tertiary
18
Q
Decomposers
A
- obtain energy by breaking down dead organisms
- decomposition process releases inorganic nutrients (carbon and nitrogen) for nutrient cycling
- e.g. fungi, bacteria
19
Q
Food chain
A
- series of organisms
- energy transferred thru food
- illustrates feeding relationships btwn organisms
20
Q
Trophic lvl
A
- each stage in food chain/feeding position
21
Q
Food web
A
- consists of interlinked food chains
22
Q
Non-cyclic energy/ linear flow in ecosystem
A
- Sun is main source of energy
- Light energy converted to chemical energy by producers via photosynthesis
- Energy from producers passed frm 1 trophic level to another thru feeding
- flow of energy in ecosystem is non-cyclic, energy lost to environment as heat (respiration), doesnt return to same system
- egested and excreted materials and dead organisms contain trapped energy
23
Q
Trapped energy in excreted and dead matter
A
- egested, excreted matter and dead organisms contain trapped chemical energy
- released thru decomposition
- decomposers use some of the trapped chemical energy for own needs
- rest is lost as energy
24
Q
Ecological pyramids
A
- Pyramid of numbers
- Pyramid of biomass
- Pyramid of energy
- used to compare trophic lvls of food chain
25
Q
Pyramid of numbers
A
- comparison of number of organisms present at each trophic lvl
- particular time
26
Q
Pyramid of biomass
A
- comparison of mass of organisms
- present at each trophic lvl at particular time
- dry mass
- mass of organism after all water removed
- e.g. dry organisms in an oven until a constant mass is obtained
27
Q
Inverted/oddly shaped pyramid of numbers
A
- on 1 trophic lvl are parasitic on organisms of another trophic level
- many small organisms feed on a large organism
28
Q
Inverted/oddly shaped pyramid of biomass
A
- organisms on 1 trophic lvl has high reproductive rate (e.g. phytoplankton, zoo plankton)
- based on standing mass, not taking into account reproductive rate
29
Q
Pyramid of energy
A
- total energy in each trophic lvl of food chain
- over certain period of time
- broad at base, narrow at top
- energy lost going down food chain
30
Q
How is energy lost to environment
A
- food transfer
- heat during respiration
- uneaten body parts
- undigested matter egested by consumers
- waste products excreted by consumers
31
Q
Nutrient cycling
A
- balanced ecosystem
- nutrients not lost, continually recycled
- cycling of nutrients brought abt by physical, chemical and biological processes
- e.g. carbon
32
Q
Carbon cycle
A
- carbon constantly removed frm and released into atmosphere in the form of CO2
- conc of CO2 fairly constant (in environment)
33
Q
Importance of carbon cycle
A
- Ensures continuous supply of carbon dioxide for photosynthesis
- Enables energy to flow thru the ecosystem
- carbon compounds carry trapped solar energy from one organism to another
34
Q
Carbon cycle pathway (How CO2 is removed)
A
- removed from environment via photosynthesis
- passed on via feeding (carbon compounds becomes part of consumer’s body)
- fossil fuel (carbon compounds preserved as fossil fuels)
35
Q
Carbon cycle pathway (How CO2 released)
A
- Respiration
- carbon compounds broken down into carbon dioxide - Combustion
- complete combustion fossil fuels release CO2 - Decomposition
- organisms die, dead matter broken down into simple substances like CO2 by decomposers
36
Q
Define carbon sink
A
- area that stores carbon compounds for an indefinite period
- stores more carbon than releases
- e.g. oceans, forests
37
Q
Ocean (carbon sink)
A
- one of largests on earth
- CO2 dissolves in water absorbed and used by phytoplankton and algae (photosynthesis)
- portion of carbon compounds buried in seabed (fossil fuels e.g. natural gas, oil)
- adding iron compounds (ie. iron oxide/sulphate) increases photosynthesis activity
38
Q
Forest (carbon sink)
A
- atmospheric CO2 absorbed by plants, used in photosynthesis
- large amt of carbon compounds stored in trees
- remains of dead trees form coal (fossil fuel)
