2.1 Species & Populations Flashcards
Define a species
A group of organisms that share common characteristics and are able to reproduce with each other to produce fertile offspring
Define population
Group of organisms of same species living in the same area at the same time reproducing with each other
Define a habitat
Ecological/environmental area where an organism lives due to biotic and abiotic factosr
Abiotic factors affecting habitat choice
Precipitation, temperature, soil pH, sunlight, humidity
Biotic factors affecting habitat choice
Competition
Symbiosis
Predation
Types of competition
Interspecific and intraspecific
Types of symbiosis and what they are
Parasitism - only one party is benefitted
Mutualism - all parties benefitted
Define niche
Area within a habitat where organisms live
Types of niches & what they are
Fundamental niche - where an organism COULD live based on abiotic factors
Realised niche - where an organism actually lives based on biotic factors
Types of factors affecting populations
Density-dependent factors: affecting or caused by population density
Density-independent factors
Mnemonic for density-dependent factors on populations
Predators
Availability of resources
Nutrient supply
Disease
Accumulation of waste
mnemonic for density-independent factors
Phenomena (volcanos)
Abiotic/environmental factors
Weather
Phases in an S—shaped curve
Plateau phase
Exponential growth phase
Transitional phase
Stationary phase
What populations have J shaped curves?
Smaller organisms - insects (short lives)
