Unit 2.2c

Question 1

What is co-evolution?

Answer 1

It’s the process by which two or more species, evolve in response to selection pressures imposed by each other

Question 2

Can a change in one species act as a selection pressure on another?

Answer 2

Yes, a change in traits can act as a selection pressure on another species

Question 3

Where is co-evolution usually seen?

Answer 3

In pairs of species that have symbiotic interactions

Question 4

What is symbiosis?

Answer 4

It’s where members of two different species have co-evolved intimate relationships

Question 5

Symbiotic relationships can be 1, 2 or 3 for individuals involved

Answer 5

1. Positive
2. Negative
3. Neutral

Question 6

What are the three types of symbiotic relationships/interactions?

Answer 6

1. Mutualism
2. Commensalism
3. Parasitism

Question 7

What is mutualism?

Answer 7

This is when both organisms are interdependent on each other for resources and other services

Question 8

Is mutualism positive negative or neutral for species involved?

Answer 8

As both organisms gain from the relationship, the interaction is positive for both

Question 9

What is commensalism?

Answer 9

It is the only one organism benefits from the relationship, the other is unaffected

Question 10

Is commensalism positive negative or neutral for the species involved?

Answer 10

It is positive for one and neutral for the other

Question 11

What is parasitism?

Answer 11

This is when a parasite benefits from its host by using up its energy and nutrients

Question 12

Is parasitism positive negative or neutral for the species involved?

Answer 12

It is negative for the host and positive for the parasite

Question 13

What does the red queen hypothesis state?

Answer 13

In a co-evolutionary relationship, changing the traits of one species can act as a selection pressure on the other species.

This means that species in these relationships must adapt to avoid extinction.