Chapter 54: Community Ecology

Question 1

What is biodiversity?

Answer 1

The variety of life across all levels of biological organization

• genetic diversity
• species diversity
• ecosystem diversity

Question 2

What is genetic diversity?

Answer 2

Varying genes that make up the characteristics of a species

Question 3

What is species diversity?

Answer 3

Number of different species in a particular region

Two parts:
Species richness
Species evenness

Question 4

What is ecosystem diversity?

Answer 4

Variety of habitats and communities in the world

Question 5

What is species richness?

Answer 5

The number of species

Question 6

What is species evenness?

Answer 6

The relative abundance of the species in that environment

How many there are for that environment

Question 7

Answer the following for each location:

a) What is the species richness?
b) What is the species evenness?

Location 1:

• One tree
• Nine of the same shrub

Location 2:

• Five of the same tree
• Five of the same shrub

Answer 7

Location 1:

a) Species richness = 2
b) Species evenness = low

Location 2:

a) Species richness = 2
b) Species evenness = high

Question 8

What does the Berger-Parker Index say about diversity?

Answer 8

The sample with greater evenness is more diverse than the sample with greater richness

Question 9

How are community interactions classified?

Answer 9

By whether they help, harm, or have no effect on the species involved.

Question 10

What are the 4 community interactions?

Answer 10

1. Competition
2. Predation
3. Herbivory
4. Symbiosis
   
   • parasitism
   • mutualism
   • commensalism

Question 11

What is competition?

Answer 11

When two or more species try to obtain the same limited resources

Question 12

What is predation?

Answer 12

An interaction between species where the predator kills the prey

Question 13

What is herbivory?

Answer 13

When plants are consumed by animals

Question 14

What is symbiosis?

Answer 14

When individuals of 2 or more species live in direct and intimate contact with one another

Question 15

What is parasitism?

Answer 15

When one organism feeds on the other (host)

- host receives no benefit

Question 16

What is mutualism?

Answer 16

When both individuals benefit from the relationship

E.g., ants feed off of acacia plants for nutrients, and the acacia plants are protected by the ants.

Question 17

What is commensalism?

Answer 17

An interaction in which one species benefits and the other is neither benefited or harmed

E.g., birds nest in trees, tree is not benefited or harmed.

Question 18

What are hitchhiking species?

Answer 18

Species that partake in commensalism on the go.

E.g., algae on turtle shells, barnacles on whales etc.

Question 19

Does competition have a positive or negative effect on both species?

Answer 19

Negative on both

Question 20

Does predation have a positive or negative effect on both species?

Answer 20

Positive for the predator

Negative for the prey

Question 21

Does parasitism have a positive or negative effect on both species?

Answer 21

Positive for the parasite

Negative for the host

Question 22

Does mutualism have a positive or negative effect on both species?

Answer 22

Positive on both

Question 23

Does commensalism have a positive or negative effect on both species?

Answer 23

Positive for one species

Neither +/- for other

Question 24

What is the competitive exclusion principle?

Answer 24

Principle which states that the species that acquires more of the resources will win and the other species will die out

Question 25

How are species able to coexist?

Answer 25

Both species will confine themselves to a particular niche in the same environment

E.g., there are two types of barnacles. Barnacle type 1 lives on the part of the rock that receives high tide. Barnacle type 2 lives on the part of the rock gang receives low tide. If barnacle type 2 was absent, barnacle type 1 would cover the entire rock, however, they are coexisting together.

Question 26

What is resource partitioning?

Answer 26

When similar species focus on different resources/niches in order to coexist in a community

E.g., multiple bird species can live in the same tree. Some with live at the top of the tree while another lives in the middle.

Question 27

What is character displacement?

Answer 27

When a species in a habitat will diverge because competing for a specific niche has restricted them to specific resources

Question 28

What are 4 characteristics that prey can do in order to prevent themselves from being eaten?

Answer 28

Camouflage
Warning coloration
Chemical defenses
Mimicry

Question 29

What is cryptic coloration?

Answer 29

Camouflage, where the organisms appearance can blend in with a background.

Question 30

What is warning coloration?

Answer 30

Aposematic coloration

When an organism will physically change its color in order to show or pretend it is venomous to frighten the predator away

Question 31

What is mimicry?

Answer 31

When an organism pretends to be another in order to deter predators

Question 32

What is Batesian mimicry?

Answer 32

When a species evolves to resemble a species that has superior, protective capability.

Question 33

In Batesian mimicry there are 3 players: the model, the mimic, and the dupe. How does each one play?

Answer 33

The model is the species with the superior, protective capability.

The mimic is the species pretending to be the model.

The dupe in the predator fooled into believing that the mimic is the model.

Question 34

What is a habitat?

Answer 34

The physical surroundings in which a species can normally be found

Question 35

What is a niche?

Answer 35

All of the resources required for the survival, growth, and reproduction of a species.

• light, temperature and chemicals are also part of the niche

Question 36

What is a keystone species?

Answer 36

A species who’s a sense from a community would bring about significant change.

• not every community has a keystone species