Competition

Question 1

Fill in the table: Types of interactions
             A-B+      A-B0     A-B-
B-A+.       1.            2.          3
B-A0.      2.            4.          5
B-A-        3.            5           6

Answer 1

Square 1: Mutualism
Square 2: Commensalism 
Square 3: exploitation
Square 4: No interaction
Square 5: Amensalism
Square 6: Competition

Question 2

What is considered to be exploitation?

Answer 2

Predation, herbivory, parasitism, parasitoids

Question 3

How does competition have a negative effect on both individuals involved?

Answer 3

It lowers their fitness. Energy spent competing could’ve instead been used for survival and reproduction

Question 4

What makes species more likely to compete?

Answer 4

Share similar niches or traits, if they’re the same species or closely related species

Question 5

What is Gause’s competitive exclusion principle?

Answer 5

Two species with the same niche can’t coexist, one will eventually outcompete the other

Question 6

What is competition and why do organisms compete?

Answer 6

A reciprocally negative relationship between two organisms. Compete for limited food, reproductive resources, habitat

Question 7

What are the 6 types of competition?

Answer 7

Consumption/scramble
Pre-emptive 
Overgrowth
Chemical interaction 
Territoriality 
Direct encounter

Question 8

What is consumption competition?

Answer 8

Indirect competition that involves eating all the food before the competitors get to it

Question 9

What is pre-emptive competition?

Answer 9

Indirect competition where the winner is the first one to occupy a habitat

Question 10

What is overgrowth competition?

Answer 10

One plant species outgrows another (strangler fig)

Question 11

What is chemical interaction competition?

Answer 11

Allelopathy, plants produce chemicals that prevent growth or germination of other plants

Question 12

What is territoriality competition?

Answer 12

An individual defending an area. Can be posturing, but will eventually lead to confrontation

Question 13

What is direct encounter competition?

Answer 13

Direct fighting for resources

Question 14

What are the 4 possible outcomes of competition in the Lotka-Volterra models?

Answer 14

1. Species 1 drives species 2 to extinction
2. Species 2 drives species 1 to extinction
3. Either species may win, depends on initial population size
4. Neither wins and they coexist

Question 15

What is the α term in the Lotka-Volterra equations? What does it mean when α is >1, <1, and 0?

Answer 15

The conversion factor between species. If α > 1, adding an individual of the other species has a greater effect than adding an individual of the same species. If α < 1, self-limitation is stronger than interspecific competition. If α = 0, there is no competition