Unit 2.1

Question 1

Mutualism

Answer 1

A symbiotic relationship where both parties benefit from each other.

Question 2

Example of mutualism

Answer 2

An example is the relationship between mycorrhizal fungi and plant roots. The fungus grows around and into roots providing roots with otherwise unavailable nitrogen from the soil. Roots provide fungi with food produced by photosynthesis.

Question 3

Parasitism

Answer 3

A symbiotic relationship in which one species benefits and the other is unfavorably affected

Question 4

An example of parasitism

Answer 4

An example is the relationship between varroa mites and honeybees. Parasites rarely kill their hosts as this is evolutionarily counter-productive. The mites live in the breathing tubes of the bees, sucking their blood and weakening them.

Question 5

Competition

Answer 5

An example is an interaction of wolves in a wolf pack trying to feed on a moose. It is an intraspecific competition where the wolves are of the same species.

Question 6

Pioneer species

Answer 6

The first species to colonize an ecosystem which might be following a disturbance

Question 7

An example of pioneer species

Answer 7

planktons, fungi, bacteria, lichens