Chapter 4-Ecology Flashcards
Species
A group of organisms with a common ancestor that can breed and produce fertile offspring
Population
A group of organisms of the same species who live in the same area at the same time
What are the 2 types of method to obtain nutrients, and the explanations?
1) Autotrophic = organisms that make their own C compounds
2) Heterotrophic = organisms that obtain C compounds from other organisms
Detritrivores
Heterotrophs that obtain organic nutrients from detritus by internal digestion
Saprotrophs
Heterotrophs that obtain organic nutrients from dead organic matter by external digestion
→ secretes enzymes into the environment to digest the dead organic matter
Communities
All the populations of different specie living together and interacting with e.o
(All the populations in an ecosystem)
Ecosystem
A community forms an ecosystem by its interactions with the abiotic environment
3 requirements of a sustainable ecosystem
1) Nutrient availability
2) Detoxification of waste products
3) Energy availability
Mesocosm
Self contained ecosystem
→ Allows a small part of the natural environment to be observed under controlled conditions
3 groups of autotrophs that can carry out photosynthesis
1) plants
2) eukaryotic algae
3) cyanobacteria
Food chain
A sequence of organisms, each of which feeds on the previous one
3 activities that living organisms need energy for?
1) Synthesising large molecules like DNA, RNA and proteins
2) Pumping molecules or ions across membranes by active transport
3) Moving things around inside the cell, s.a chromosomes or vesicles, or in muscle cells the protein fibres that cause muscle contraction
The energy conversions performed by living organisms (4)
Light energy → chemical energy in photosynthesis
Chemical energy → kinetic energy in muscle contraction
Chemical energy → electrical energy in muscle cells
Chemical energy → heat energy in heat generating adipose tissue
Laws of thermodynamics
Heat passes from hotter place to a cooler place
→ heat produced in living organisms is eventually lost to the abiotic environment
Biomass
The total mass of a group of organims
→ has energy
Most of the energy in the food that is digested and absorbed by organisms in a tropic level = released by respiration in cell activity
SO what is left for other organisms in higher trophic levels?
Chemical energy in carbs and other C compounds that haven’t been used up in cell respiration
Another 2 reasons why not all energy is transferred in successive trophic levels
1) The organisms in a trophic level are not entirely consumes by organisms in the next
2) Not all parts of foods ingested by organisms in a trophic level are digested and absorbed
Units for pyramid of energy
kJm^-2yr^-1
energy/unit area (m^2)/yr
Carbon fixation
When autotrophs convert carbon dioxide into carbohydrates and other carbon compounds
Methanogenesis
Methane is produced fro organic matter in anaerobic respiration by METHANOGENIC ARCHAEANS and some diffuses into the atmosphere
3 different groups of anaerobic prokaryotes
1) Bacteria that convert organic matter into a mixture of organic acids, alcohol, hydrogen and carbon dioxide
2) Bacteria that uses the organic acids and alcohol to produce acetate, carbon dioxide and hydrogen
3) Archaeans that produce methane from carbon dioxide, hydrogen and acetate
4 different environments that methanogenesis can happen
1) Mud along shores and bed of lakes
2) Swamps, mangrove forests, wetlands where the soil or peat deposits are waterlogged
3) Guts of termites and of ruminant mammals (cattle, sheep)
4) Landfill sites where organic matter is in wastes that have been buried
