Poikilothermic host in Plasmodium life cycle

Plasmodium is a protozoan parasite that causes malaria in humans. The life cycle of Plasmodium involves both a vertebrate host (human) and an invertebrate host (mosquito). The mosquito, specifically the Anopheles species, acts as the vector that transmits the parasite from one host to another. In the Plasmodium life cycle, the poikilothermic host refers to a host whose body temperature varies with the ambient temperature. The correct answer to the question is option 'B', Anopheles mosquito, as it is a poikilothermic host in the Plasmodium life cycle.

Explanation:
The Plasmodium life cycle consists of two main phases: the sporogonic phase in the mosquito vector and the schizogonic phase in the human host. Let's take a closer look at the role of the Anopheles mosquito as a poikilothermic host in the Plasmodium life cycle.

Anopheles mosquito as the vector:
- The female Anopheles mosquito is responsible for transmitting the Plasmodium parasite to humans.
- When an infected mosquito bites a human, it injects sporozoites, the infective stage of Plasmodium, into the bloodstream.

Poikilothermic nature of Anopheles mosquito:
- Anopheles mosquitoes are considered poikilothermic organisms because their body temperature varies with the ambient temperature.
- Unlike humans and other mammals, Anopheles mosquitoes do not have the ability to regulate their body temperature internally.
- Instead, they rely on external factors such as sunlight and environmental temperature to regulate their body temperature.

Impact on Plasmodium life cycle:
- The poikilothermic nature of Anopheles mosquitoes plays a crucial role in the development and transmission of Plasmodium.
- The sporozoites injected by the mosquito into the human host require a specific temperature range to develop and multiply.
- The optimal temperature for sporozoite development is usually around 25-30°C, which coincides with the body temperature of the Anopheles mosquito.

Conclusion:
In conclusion, the poikilothermic nature of the Anopheles mosquito makes it an ideal host for the development and transmission of Plasmodium. The temperature variations in the mosquito's body allow the sporozoites to undergo their required developmental stages before being transmitted to a human host. Understanding the role of different hosts in the Plasmodium life cycle is crucial for the prevention and control of malaria.