When using a quadrat to estimate population size, we use a random number generator to avoid what?
Bias
A method of estimating population size of motile organisms by marking a number of them, releasing them & then counting the number of marked organisms in a second sample
Mark, release & recapture
Give two assumptions made when using the mark, release, recapture technique to estimate population size
No immigration / migration (Ignore ref to emigration);
No reproduction (Ignore ref to death);
Idea of mixing;
Marking does not influence behaviour
Two examples of biotic factors that affect the population size of an organism
disease,
predation,
competition
A self contained area including the biotic (living) community and abiotic (non-living) components interacting with one another
Ecosystem
The differences between organisms of different species.
Interspecific variation
The place where an organism lives
Habitat
a sampling area used for measuring the frequency or percentage cover of organisms (plants or slow moving organisms)
Quadrat
the category of living factors in the environment of an organism that affect population size
Biotic factors
Competition between organisms of the SAME species e.g. for food or mates
Intraspecific competition
Conditions in the environment that limit population size - these can be biotic or abiotic factors.
Limiting factors
The range and variety of genes, species and habitats within a particular ecosystem
Biodiversity
All organisms of all populations in an ecosystem
Community
A line along which organisms can be sampled in ecological studies. Particularly useful in ecosystems such as sea shores and sand dunes where abiotic conditions and species vary across the area being studied.
Belt transect
This describes how an organism fits into the environment. It describes what a species is like, where it occurs, how it behaves, its interactions with other species and how it responds to its environment.
Niche
all of the organisms of one species in an ecosystem
Population
When using a quadrat to estimate population size, we take many samples to ensure that our data is what?
Representative of the population
Differences between organisms of the same species
Intraspecific variation
The study of inter-relationships between organisms & their environment
This environment includes living (biotic) factors (e.g. competition & predation) & non-living (abiotic) factors (e.g. temperature & rainfall).
Ecology
Give two examples of abiotic factors
temperature,
oxygen concentration,
pH,
light,
carbon dioxide concentration
competition between organisms of DIFFERENT species e.g. for food
Interspecific competition
Where one organism is consumed by another
Predation
A group of similar organisms that can reproduce to produce FERTILE offspring
Species
the non-living / physical part of an ecosystem that can affect population size
Abiotic factors
The population size of a species that can be supported by the ecosystem
Carrying capacity