3.5 Criteria Flashcards
Define symbiosis:
An intimate relationship between two members of different species
Symbiosis is the result of a partnership over time resulting in what?
Co-evolution
A parasite benefits in terms of what?
Energy or nutrients given by the host
A host is harmed in terms of what?
The loss of energy or nutrients taken by the parasite
What do parasites occupy?
A limited metabolism
Most parasites cannot survive out of contact with the host. Give an example of this.
Tapeworm has no gut, so without the human digestive system it cannot get nutrients
Parasites may be transmitted to new hosts using what? (3)
- Direct contact
- Resistant stages
- Vectors
What is meant by direct contact?
Parasite is directly transmitted to the host
Example of direct contact of parasites:
Head lice
What is meant by resistant stages?
When parasites use resistant larvae and pupae, which can survive adverse environmental conditions until a new host comes in contact with them.
Example of a parasite which uses resistant stages:
Fleas
What is meant by vector?
A carrier of a disease-causing agent from an infected individual to a non-infected individual or its food or environment
Example of a vector of a parasite:
Culex mosquitoes are used by the plasmodium parasite
Some parasitic lifecycles involve intermediate (secondary) hosts to allow them to complete their lifecycle. Give an example
Humans are the intermediate hosts for Plasmodium where gamete release occurs, but fertilisation happens in the mosquito.
Define mutualism
A form of symbiosis where each mutualistic partner benefits in the interdependent relationship
Give an example of mutualism:
COral polyps and zooxanthellae algae
