concepts relating to environmental indicators

Question 1

what is a niche?

Answer 1

a niche is the role that a given species plays in the community.

Question 2

what is a specialist organism?

Answer 2

occupy specific ecological niches

Question 3

what are generalist organisms?

Answer 3

occupy broad ecological niches

Question 4

what are the advantages of generalists over specialists?

Answer 4

generalists are able to adapt to changes much better than specialists because of their broad tolerance ranges.

Question 5

what are autotrophs and an example?

Answer 5

autotrophs produce their own food from a principle inorganic carbon source such as CO2, an example is a plant.

Question 6

what are hetrotrophs and an example?

Answer 6

rely on other organisms for food, meaning that the principle carbon source is organic. Eg: fish

Question 7

what does a food web do?

Answer 7

hows the connections between animals and producers within an ecosystem, a food chain is a more general version of a food web.

Question 8

what are satrotrophs?

Answer 8

are decomposers meaning they derive from dietary needs by absorbing the products or remains of other organisms. Eg: fungi

Question 9

what is involved in a predator/prey relationship and an example?

Answer 9

predators eat other animals (usually either omnivores/carnivores).
eg: foxes and hoping mouse.

Question 10

what are pests and an example?

Answer 10

pests are animals which destroy the ecosystem it encompasses without any real benefits to the ecosystem and are not apart of a natural cycle.
eg: rabbits

Question 11

what is a range of tolerance?

Answer 11

the range at which abiotic factors allow an organism to survive in

Question 12

what is a tolerance limit?

Answer 12

the point at which chemical or physical conditions become harmful to an organism

Question 13

what is a threshold?

Answer 13

the point at which a certain level of concentration is reached and an effect is observed

Question 14

what is a threshold pollutant and an example?

Answer 14

a substance that is harmful to a particular organism once it reaches a particular concentration, or threshold level
eg: an oil spill

Question 15

what is a limiting factor/condition and an example?

Answer 15

conditions that approach or exceed an organisms limits of tolerance
eg: when the temperature of the water is too high.

Question 16

what is a standard and an example?

Answer 16

environmental indicators which identify healthy levels of the environment
eg: a safe PH level is 7.

Question 17

what is a bio marker species?

Answer 17

bio marker species have low thresholds for particular contaminants and therefore, their genetic structure can easily be changed, the frequency of changes is what can be measured through these species.

Question 18

what is an introduced species?

Answer 18

out compete native animals, are animals which were not originally found in a particular area.

Question 19

what are some factors which may effect the threshold of an organism?

Answer 19

the type of organism, the stage at its life cycle, the pollutants in the ecosystem and the type of ecosystem.

Question 20

how can specialist organism such as the dragonfly nymph be a good biological indicator?

Answer 20

specialist species have small tolerance ranges, so when the smallest of changes occurs, they are absent, indicating a poor environment.

Question 21

think of a situation which shows the connection between tolerance limit and limiting factors.

Answer 21

when a limiting factor such as an oil spill occurs many marine organisms, such as fish, will have reached their tolerance limits.