Ecology

Question 1

What is Ecology?

Answer 1

Ecology is the study of the relationships among organisms and their environemnt.

Question 2

What is an Organism?

Answer 2

An organism is an individual living thing. Eg. Alligator

Question 3

What is a population?

Answer 3

A population is a group of the same species that lives in one area.

Question 4

What is a community?

Answer 4

A community is a group of different species that live together in one area.

Question 5

What is an ecosystem?

Answer 5

An ecosystem includes all of the organisms and the abiotic factors in a given area.

Question 6

What is a Biome?

Answer 6

A biome is a major regional or global community of organisms characterised by the climatic conditions and plant communities that thrive there.

Question 7

What is the biosphere?

Answer 7

Life supporting portions of Earth composed of air, land, fresh water and salt water.

Question 8

Habitat vs. Niche

Answer 8

Habitat - the place in which an organism lives (address)

Niche - is the role a species plays in a community (job)

Question 9

Habitat vs. Niche

Answer 9

Habitat - the place in which an organism lives (address)

Niche - is the role a species plays in a community (job)

Question 10

What is a Limiting Factor?

Answer 10

Any biotic or abiotic factor that restricts the existence of organisms in a specific environment.

Question 11

What is a food chain?

Answer 11

a model that shows a linear sequence of

feeding relationships.

Question 12

What is a food web?

Answer 12

It shows a complex network of feeding relationships within an ecosystem.

Question 13

What are decomposers?

Answer 13

Decomposers are microbes which feed on dead or decaying remains and waste. They use enzymes to break down the remains into soluble substances. They absorb these substances and by excretion and respiration, return all chemicals to the soil or to the air.

Question 14

What are trophic levels?

Answer 14

They represent a feeding step in the transfer of energy and matter in an ecosystem.

Question 15

What is Biomass?

Answer 15

the amount of organic matter comprising a group of organisms in a habitat.

Question 16

Why does biomass usually decrease going up the pyramid

Answer 16

1. One organism (oak tree) can feed an entire population.
2. The energy passes on to the next trophic level diminishes at each stage, leaving less energy to support a large number of organisms.

Find drymass and multiply by # of organisms.

Question 17

Why is energy lost ?

Answer 17

Energy is lost at a rate of 90%, because organisms use the energy gained through eating for their metabolic processes ( warm-blooded). They use it for movement, reproduction and can’t digest every part of their meal. They lose it through respiration, faeces and urine.

Question 18

Why are food webs sometimes unbalaced?

Answer 18

1. Over predation
2. Disease
3. Pollution
4. Use of pesticides
5. Lack of food or other resource
6. Emigration (invasive species).