Principles of Ecology

Question 1

what is Ecology?

Answer 1

• The study of how organisms interact with …
  » members of same species (population ecology)
  » members of different species (community ecology)
  » their environment

Question 2

What is the Ecological Hierarchy?

Answer 2

• Individual
  » An organism that is born, grows and eventually dies
• Population
  » A group of organisms of the same species that live in the same area
• Community
  » Different populations of species living in the same area (that may or may not interact)
• Ecosystem
  » The combination of the community of species (biotic) and the abiotic (non-living) environment

Question 3

What are the levels of biological complexity?

Answer 3

1) molecule
2) organelle
3) cell
4) tissue
5) organ
6) organ system
7) organism
8) population
9) ecosystem

Question 4

What are Abiotic factors?

Answer 4

• Abiotic factors = non-living components
  » Climate (temperature, precipitation, sunlight etc)
  » Geochemistry (soil, salinity, nutrients, pH etc)

Question 5

Why are abiotic factors important?

Answer 5

• Abiotic factors have a significant impact on the environment and determine the type of ecosstems that are possible (i.e. rain, nutrient availability etc.)

Question 6

What are biotic factors?

Answer 6

• Biotic factors = living components equally important in determining the type of ecosystem
  » Different species and their interactions
  » Resources, which are both
  • necessary for survival
  • reduced when used

Question 7

How are community interactions classified?

Answer 7

• Can be classified by whether they help, harm, or have no effect on species involved, e.g.
  » Antagonistic (+/-)
  » Mutualistic (+/+)
  » Competitive (-/-)

Question 8

What is an Antagonistic interaction?

Answer 8

» Antagonistic (+/-)
• Predation: Predator kills and eats prey
• Herbivory: Herbivore eats parts of plant or alga
• Parasitism: Parasite derives nourishment from host, which is harmed in the process (eg wasp laying eggs)

Question 9

What is a mutualistic interaction?

Answer 9

» Mutualistic (+/+)
• Mutualism: Interaction that benefits both organisms (eg nitrogen fixing bacteria and plant root, cellulose digestion in termite gut, photosynthetic algae in coral)

Question 10

What is a competitive interaction?

Answer 10

» Competitive (-/-)

• Competition: Different species compete for resources that limit their survival

Question 11

What are the non-beneficial types of species interactions?

Answer 11

• Competition (- for the initiator, - for the recipient)

- Amensalism (0 for the initiator, - for the recipient)

Question 12

What are the one sided forms of species interactions?

Answer 12

• Predation (+ for the initiator, - for the recipient)
• Herbivory (+ for the initiator, - for the recipient)
• Parasitism (+ for the initiator, - for the recipient)

Question 13

What are the beneficial types of species interactions?

Answer 13

• Commensalism (+ for the initiator, 0 for the recipient)

- Mutualism (+ for the initiator, + for the recipient)

Question 14

What is generally the first trophic level of the food chain for land animals?

Answer 14

• primary producers

- aka plants

Question 15

What is generally the 2nd trophic level of the food chain for land animals?

Answer 15

• Primary consumers

- e.g. insects/herbivore

Question 16

What is generally the 3rd trophic level of the food chain for land animals?

Answer 16

• Secondary consumers

- e.g. mouse/small carnivore

Question 17

What is generally the 4th trophic level of the food chain for land animals?

Answer 17

• Tertiary consumers

- e.g. snake/larger carnivore

Question 18

What is generally the 5th trophic level of the food chain for land animals?

Answer 18

• Quaternary consumers

- e.g. hawk/ large carnivore

Question 19

What are decomposers and how do they fit into food chains?

Answer 19

• Decomposers are small organisms which feed on the remains of organisms from all trophic levelsand break down what is left of them after they die

Question 20

How are food webs different to food chains

Answer 20

Food chains are more simple and only focus specific species whereas a food web is more complex and demonstrates all species that fit into the energy cycle of various animals