Genetics
Populations
Evolutions
\
Ecosystems
,Key Terms
ECOSYSTEM: Group of interrelated organisms and their physical environment in a particular area
E.g: Sahara dessert
POPULATION: All the organisms of one species living in a particular habitat at the same time
E.g: all oak trees in wood
COMMUNITY: all the populations of all species that live together in a particular ecosystem/habitat
at the same time
E.g: org living in rock pool
·
ABIOTIC FACTORS: non-living condition that affects
E.g: salt conc of rock pool, pH , temp, 02 conc, CO2 conc
BIOTIC FACTORS: Effects of the activities of living organisms on other organisms
E.g: effect of snails grazing on pondweed
AUTOTROPHS: An organism that makes its own food
• photosynthesising org
• Start of food chain
• Plants , algae
HETEROTROPHS: Organisms that obtain food by consuming other organisms
,HERBIVORES: Organisms that eat only plants
OMNIVORES: Organisms that eat both plants and other organisms
CARNIVORES: Organisms that only eat meat
PRIMARY CONSUMERS: Organisms that consume producers
SECONDARY CONSUMERS: organisms that consume primary consumers
TERTIARY ORGANISMS: organisms that consume secondary consumers
DECOMPOSERS: Organisms that break down the dead matter
Biomes
• largest subunits of biosphere
• in each biome diff ecosystems
• Contain dynamic , self-sustaining, stable community of org
• Interact w each other + non-living surroundings
• contain several habitats
• environment = organism's total surroundings, including living dead and non-living components
Population Size
• Ecosystems carrying capacity = size of pop of a species it can support
Pop size can vary bc of:
1. Effect of abiotic factors
2. Interactions betw organisms (comp + predation)
* Abiotic factors aff survival + reproductive success
, Effe of Abiotic Faors
Temperature
• affect enzyme controlled reactions
• Denature key enzymes + proteins
• E.g: ATP synthase - ATP not produced
Lights
• less light - dec rate of photosynthesis
• Producer pop dec
• Aff size of all consumers (pop)
pH
• aquatic organisms
• Enxyme activity - in producers
Water + Humidity
• metabolite
• Solvent
• Reactions limited - photosynthesis , condensation , hydrolysis
Competition
• living in same area need to survive from res in that area
• If res limited - comp betw these species
1. INTRASPECIFIC COMPETITION
• comp betw members of same species
• limits growth of population
• Led to special forms of beh : ritualised fighting + territorial behaviour
2. INTERSPECIFIC COMPETITION
• comp betw 2 dif species for limited resource
• Expl changes in pop size, extinction + evol of species ·
* compete over food sources + habitats
Populations
Evolutions
\
Ecosystems
,Key Terms
ECOSYSTEM: Group of interrelated organisms and their physical environment in a particular area
E.g: Sahara dessert
POPULATION: All the organisms of one species living in a particular habitat at the same time
E.g: all oak trees in wood
COMMUNITY: all the populations of all species that live together in a particular ecosystem/habitat
at the same time
E.g: org living in rock pool
·
ABIOTIC FACTORS: non-living condition that affects
E.g: salt conc of rock pool, pH , temp, 02 conc, CO2 conc
BIOTIC FACTORS: Effects of the activities of living organisms on other organisms
E.g: effect of snails grazing on pondweed
AUTOTROPHS: An organism that makes its own food
• photosynthesising org
• Start of food chain
• Plants , algae
HETEROTROPHS: Organisms that obtain food by consuming other organisms
,HERBIVORES: Organisms that eat only plants
OMNIVORES: Organisms that eat both plants and other organisms
CARNIVORES: Organisms that only eat meat
PRIMARY CONSUMERS: Organisms that consume producers
SECONDARY CONSUMERS: organisms that consume primary consumers
TERTIARY ORGANISMS: organisms that consume secondary consumers
DECOMPOSERS: Organisms that break down the dead matter
Biomes
• largest subunits of biosphere
• in each biome diff ecosystems
• Contain dynamic , self-sustaining, stable community of org
• Interact w each other + non-living surroundings
• contain several habitats
• environment = organism's total surroundings, including living dead and non-living components
Population Size
• Ecosystems carrying capacity = size of pop of a species it can support
Pop size can vary bc of:
1. Effect of abiotic factors
2. Interactions betw organisms (comp + predation)
* Abiotic factors aff survival + reproductive success
, Effe of Abiotic Faors
Temperature
• affect enzyme controlled reactions
• Denature key enzymes + proteins
• E.g: ATP synthase - ATP not produced
Lights
• less light - dec rate of photosynthesis
• Producer pop dec
• Aff size of all consumers (pop)
pH
• aquatic organisms
• Enxyme activity - in producers
Water + Humidity
• metabolite
• Solvent
• Reactions limited - photosynthesis , condensation , hydrolysis
Competition
• living in same area need to survive from res in that area
• If res limited - comp betw these species
1. INTRASPECIFIC COMPETITION
• comp betw members of same species
• limits growth of population
• Led to special forms of beh : ritualised fighting + territorial behaviour
2. INTERSPECIFIC COMPETITION
• comp betw 2 dif species for limited resource
• Expl changes in pop size, extinction + evol of species ·
* compete over food sources + habitats
