Chapters 24 And 25 Flashcards
1
Q
The levels of organization
A
Atom Molecular level
Molecular level
Organelle level
Cellular level
Tissue level
Organ level
Systemic level
Organism level
2
Q
Levels of organization for ecology
A
Species
Population
Community
Ecosystem
Biosphere
3
Q
Biosphere
A
- all the ecosystems on Earth
- “portion of the Earth that contains living organisms”
4
Q
Ecosystem
A
- a community or organisms and the physical environment in which they live
- “specific areas of the biosphere where organisms interact”
5
Q
Biomes
A
- major types of terrestrial ecosystems
- Defined by climate conditions
6
Q
Biotic components of an ecosystem
A
- ecosystem includes both living and non living components
- Biomass: total living component of an ecosystem
- nonliving components include: chemical elements; an essential constant supply of energy
- biotic components are categorized by how they obtain their energy
7
Q
Energy low through ecosystems obeys the laws of thermodynamics
A
- first law of thermodynamics: energy is neither created nor destroyed; energy can change form
- second law of thermodynamics: some energy is wasted when it changes form or is transferred; energy is usually converted to heat
8
Q
Producers
A
- capture and convert energy
- make their won organic molecules
- i.e., they produce food
9
Q
Consumers
A
- acquire organic molecules and energy by consuming other organisms
I.e., they consume food
10
Q
Energy flow
A
- sun -> producers -> consumers
11
Q
Producers -> autotrophs
A
- “self-nutritive” or “self-growing”
- most producers are capable of photosynthesis
- terrestrial ecosystems: plants
- aquatic ecosystems: algae - equation for photosynthesis:
CO2 + H2O -> C6H12O6 + O2 = Glucose - some autotrophs are capable of chemosynthesis
12
Q
Consumers -> heterotrophs
A
- most consume foods that already contain stored forms of energy
- Herbivores: primary consumers; use green plants as an energy source
- Carnivores: secondary or tertiary consumers; use other animals as energy source
- Omnivores: use either plants or animals as energy source
- Decomposers: use dead organisms as energy source
13
Q
Niche
A
- the role of an organism in an ecosystem
(producer vs. Omnivore) - How an organism: gets food, interacts with other populations, physical habitat
- well-balanced ecosystem supports a wider variety of species, each with a different niche
- niches may overlap, resulting in competition between species for limited resources
14
Q
How is energy flow depicting
A
- energy flow is often depicted as a chain of events
I.e., food chain; however, this (much like the scientific process) is a “watered down” example
- similar to the scientific method vs. the scientific process
15
Q
Food web
A
- a diagram describing trophic, or feeding relationship
- grazing food web
- detrital food web
16
Q
Habitat
A
- location where a species lives
- has certain chemical and physical characteristics favorable to the organism’s comfort and survival
17
Q
Geographic range
A
- the area over which a species is found
- limitations: competition for resources, intolerable conditions, physical obstacles
18
Q
The lower levels of an ecological pyramid support consumers populations
A
- depict total biomass or total energy stored at each level of an ecosystem
- producers capture approximately 2% of the energy in sunlight
- only about 10% of the energy from a lower level is available to the next higher level
- lower level of ecological pyramid support consumer populations
- consumers at any level depend critically on the populations of consumers directly below it
- small amounts of energy available to tertiary consumers depends on energy transfers at all levels below them
19
Q
Human activities that disrupt ecological pyramids
A
- humans as primary consumers (eating plants)
- humans as secondary consumers (eating meat; utilizing only 10% of energy that would be available from plants)
- modern farming practices exclude other species or heir place in the food web and their ecological pyramid
20
Q
Biogeochemical cycles
A
- includes living organisms, geologic events, weather events: water cycle, carbon cycle, nitrogen cycle, phosphorus cycle
- molecules and element cycle between three different pools:
- biomass: (living organisms)
- exchange pool: (water, soil, atmosphere)
- reserve: large, but hard-to-access pool of nutrients
21
Q
The water cycle
A
Evaporation
Condensation
Precipitation
Runoff/aquifers
22
Q
Human activities that effect the water cycle
A
- withdraw from aquifers
- deforestation/clearing vegetation = increase runoff
- interfere with the natural processes that purify water
- add pollutant to water sources
23
Q
The nitrogen cycle
A
- occurs when nitrogen gas is converted to ammonium, a form that plants can use
- Nitrogen: essential component of proteins and amino acids - atmosphere: largest reservoir of nitrogen
- Nitrogen fixation: converts atmospheric nitrogen to ammonium
- Legumes: (peas, alfalfa, soybeans) - nitrification: converts ammonium to nitrate
- denitrification: converts nitrates back to nitrogen gas (N2)
24
Q
Human activities that effect the nitrogen cycle
A
- double the fixation rate by fertilizing crops
- air pollution cause tissue damage in lungs
- acid deposition
- soil acidification
- ozone depletion
