Unit 3 Key area 5

Question 1

Define the term symbiosis?

Answer 1

Symbiosis is the term used to describe the “coevolved” “intimate” relationship between two “different” species.

Question 2

state the two types of symbiotic relationship?

Answer 2

• parasitism
• mutualism

Question 3

Describe a parasitic relationship?

Answer 3

A parasitic relationship is one where the parasite benefits in terms of nutrients and energy where the host is harmed by the loss of these things

Parasites often have limited metabolism and cannot survive outside of contact with a host

Question 4

State three methods of transmission of parasites between hosts?

Answer 4

• vectors
• direct contact
• resistant stages

Question 5

Why do some parasites use secondary hosts?

Answer 5

As secondary hosts allow parasites to complete their life cycle as they allow the parasite to vary the conditions such as temperature and pH in which they grow.

Question 6

Define the term mutualism?

Answer 6

Mutualism is defined as a relationship where both organisms benefit in an independant relationship.