4.1 - 4.4 Ecology Flashcards
Define:
Species
Population
Community
Group of organisms that can interbreed and produce fertile offspring
Group of organisms of same species, live in same area, same habitat at the same time
A group of populations living and interacting with each other in an area
Define:
Ecosystem
Ecology
Niche
Habitat
Community’s interactions with abiotic environment
Study of relationships between organisms, and organisms with the environment
Organism’s role in community
Environment which a species normally lives
Autotroph?
Organism that synthesizes its own food and organic molecules via photosynthesis or chemosynthesis
Heterotroph
Organism that obtains organic molecules from other organisms
Consumer
Detritivore
Saprotroph
Organisms ingest other organic matter that is living, or has been dead for a short period
Multicellular heterotroph, obtain nutrients from detritus, internal digestion, break down detritus into smaller fragments, facilitate further decomposition by saprotrophs
Multi/unicellular heterotroph, obtain nutrients from detritus, break down organic matter through external digestion into inorganic products by secretion of enzymes
Food chain and food web definition
Trophic level
Feeding relationships in an ecosystem forming a network of complex interactions - food web
Position of an organism in food w based on its feeding relationship with other organisms in foodweb.
3 factors required for ecosystems to be sustainable
- Nutrient availability
- decomposers break down organic matter, release inorganic nutrients - Detoxification of waste
- Waste products of one species exploited as resource by another species e.g. ammonia - Energy availability
- Energy cannot be recycled, require continued energy supply to ecosystem, e.g. by sun
Mesocosm Definition
Enclosed experimental area
Set up to explore ecological relationships
Reasons for respiration
- Synthesizing large molecules
- Pumping ions by actrnsp
- Moving things, either inside the cell/muscle contractions
Why food chain is short,
- Energy lost in form of heat
- Organism not entirely consumed
- Not all parts of food eaten is digested and absorbed, some undigested parts egested in feces
- Loss of CO2, water vapour, waste materials results in diminishing biomass
- 10% of energy is passed to next trophic level
- Not enough energy for higher trophic levels, food chain is short
explain shape of pyramid of energy and units
- Stepped shape, largest bottom step being producers
- Light energy from sun converted to C compounds by photosynthesis
- Energy released from respiration used, but also converted to heat
- Heat energy loss from ecosystem
energy loss as undigested material, uneaten material, feces in excretion
-10% passed to next trophic level - Steps higher up on the pyramid of energy become successively smaller
kJ m (-2) yr (-1)
Explain flow of energy in ecosystems
Light from sun
Photosynthesis in autotrophs convert light energy to chemical energy in C compounds
Cellular respiration to release energy, also energy loss as heat
Energy passed from lower trophic level to higher trophic level when organisms ingest other organisms. Detritivores and saprotrophs obtain energy from detritus.
Energy loss due to undigested material, uneaten material, feces, waste products, CO2
Only 10% passed on to next trophic level.
Energy is not recycled
Recall how to draw Carbon cycle
CO2 in air and water
organic compounds in producers
organic compounds in consumers
organic compounds in saprotrophic bacteria/fungi
fossil fuels
combustion
cell respiration
death
death and egestion
feeding
photosynthesis
incomplete decomposition, mineralization
Key processes of C cycle - essay (6)
Respiration: carbon compounds broken down, carbon dioxide released into env
Photosynthesis: autotrophs remove co2 from environment, fix as organic compounds
Feeding: carbon in organic molecules move from one organism in food chain to another
Combustion: burning of fossil fuels release CO2
Fossilization: incomplete decomposition and mineralization of dead organisms, carbon in organic molecules become trapped in sediment
Decomposition: Carbon in organic molecules of detritus broken down by decomposers into simpler organic and inorganic products, CO2 released as byproduct of respiration
Sources of CO2 - essay
Respiration
Production and oxidation of methane
- methanogenesis
: anaerobic conditions, by methanogens
: organic molecules to organic acids and alcohol, CO2
: Organic acids, alcohol to acetate, CO2, H2
: Methanogens > acetate, Co2, H2 to methane
- oxidation of methane
: methane oxidized in O2 in air to form Co2 and water
Combustion of biomass - forest fires
Combustion of fossilized materials
- Peat: partially decomposed organic matter by saprotrophs due to acidic anaerobic conditions, waterlogged soil. Carbon sink and source of raw material in horticulture
- Peat buried under other sediments, compressed and heated - coal
- Incomplete decomposition due to anaerobic condition > matter compressed and heated, chemical change, form liquid C compounds and gas (oil and gas) *happens at oceans normally
Volcanic eruptions
