genetics (ecosystems) Flashcards
what is a habitat?
the place where an organism lives
what is a population?
all of the organisms of one species in a habitat
what is a community?
populations of different species in a habitat
what is an ecosystem?
a community plus the abiotic conditions
what are biotic conditions?
living features of the ecosystem, eg the presence of predators or food
what are the abiotic conditions?
non living features of an ecosystem
eg) temperature and water availability
what is a niche?
the role of a species within its habitat, can only be occupied by one species
what is an adaptation?
features that increase an organism’s chance of survival and reproduction
what are the three types of adaptation?
physiological
behavioural
anatomical
what is a physiological adaptation?
processes inside their body
what is a behavioural adaptation?
the way an organism acts
what is an anatomical adaptation?
structural features of an organisms body
what is population size?
the total number of organisms of one species in a habitat
what is the carrying capacity?
maximum stable population size
why does carrying capacity vary?
due to biotic and abiotic factors
what are the three biotic factors that cause variation in population size?
interspecific competition
intraspecific competition
predation
what is interspecific competition?
competition between different species for the same resources
what is intraspecific competition?
competition within a species for the same resources
what is predation?
where a predator kills and eats its prey
how does temperature affect population size?
further away from optimum temperature means they are less likely to survive
how does light affect population size?
increased light increases the rate of photosynthesis which increases population size as the carrying capacity is increased
how does pH affect population size?
optimum pH has the largest population size
how does water affect population size?
where water is scarce there is a smaller population size, only those who are adapted survive
how does humidity affect population size?
affects transpiration rate in plants and evaporation of water in animals/humans, those who are best adapted survive
what is succession?
the process by which an ecosystem changes over time
what is primary succession?
succession on land that has been newly formed/exposed, no soil or organic matter to begin with
what is secondary succession?
succession on land that has been cleared of plants but where soil remains
what is the first species to colonise an area called?
the pioneer species
what are the stages of primary succession?
abiotic conditions are harsh so only the pioneer species can grow
pioneer species changes the abiotic conditions, as they die a basic soil is formed
makes the conditions less hostile, which means that organisms with different adaptations can grow
these die/are decomposed so the soil is deeper and richer in minerals
larger plants can grow so the soil can maintain more water
new species compete, and change the environment
what is the final stage of succession called?
the climax community
what are the features of a temperate climate?
plenty of water
mild temperatures
little change between seasons
large trees
what are the features of a polar climate?
little water available
low temperatures
big changes between the seasons
only has shrubs/herbs
what is an artificial climax community called?
plagioclimax
what is conservation?
the protection and management of a species/habitat in a sustainable way
