Parasitism

Parasitism

Definition

• Parasitism is a biological relationship between two organisms: a parasite and its host.
• In this relationship, the parasite benefits while the host is harmed.

Benefits for the Parasite

• Parasites gain nutrients and/or energy from their host.
• Many parasites have limited metabolism and cannot survive outside their host's environment.

Harm to the Host

• The host is harmed as it loses energy and nutrients to the parasite.
• The severity of harm can vary depending on the parasite-host interaction.

Effective Parasites

• The most effective parasites are those that do not kill their host completely. This allows them to continue to receive nutrients or energy from the host.
• It ensures a sustained supply for the parasite's survival.

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Biology

Parasitism

Transmission of Parasites

• Parasites need to spread from host to host to survive and reproduce.
• They can be transmitted in various ways:
  • a. Direct Contact: Some parasites are transmitted through physical contact between individuals, like head and body lice.
  • b. Release of Resistant Stages: Certain parasites have resistant larvae or pupae that can survive adverse environmental conditions until they encounter a new host.
  • c. Use of a Vector: Some parasites use another species as a vector to transfer them from one host to another. For example, the Plasmodium parasite (causing malaria) is carried by mosquitoes.

Secondary Hosts

• Some parasites require the use of a secondary host as part of their life cycle.
• For example, tapeworms have larvae that form cysts in the organs of secondary hosts, such as fish or pigs, depending on the tapeworm species.

Summary

• Parasitism is a biological relationship in which a parasite benefits at the expense of its host.
• Parasites gain nutrients and/or energy from the host while causing harm to it.
• Effective parasites do not kill their host completely to ensure a continuous supply of nutrients.
• Parasites can be transmitted through direct contact, release of resistant stages, or with the help of a vector.
• Some parasites require a secondary host within their life cycle for reproduction.