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Health and Disease Control - Life Cycle of a Mosquito

Grade 5CBSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

A mosquito undergoes a process called complete metamorphosis, which consists of 44 distinct stages: Egg, Larva, Pupa, and Adult.

Mosquitoes are known as 'vectors' because they carry disease-causing microorganisms (pathogens) from an infected person to a healthy person. For example, the female Anopheles mosquito carries the parasite PlasmodiumPlasmodium which causes Malaria.

The first three stages of the mosquito life cycle—Egg, Larva, and Pupa—take place in stagnant H2OH_2O (water). This is why preventing water stagnation is the most effective way to control mosquito populations.

The Larva stage is also called a 'wriggler'. It feeds on organic matter in the water and breathes through a tube at the water's surface, requiring a constant supply of O2O_2.

The Pupa stage is a non-feeding stage, often called a 'tumbler'. This is where the mosquito transforms into an adult.

Disease control methods include using mosquito nets, wearing long-sleeved clothes, and using biological controls like GambusiaGambusia fish that eat mosquito larvae.

📐Formulae

Life Cycle: EggLarvaPupaAdult\text{Life Cycle: } Egg \rightarrow Larva \rightarrow Pupa \rightarrow Adult

Stagnant H2O+Warmth=Breeding Ground\text{Stagnant } H_2O + \text{Warmth} = \text{Breeding Ground}

Prevention=Source Reduction+Protection from Bites\text{Prevention} = \text{Source Reduction} + \text{Protection from Bites}

💡Examples

Problem 1:

Why is it recommended to pour a layer of kerosene or oil over stagnant pools of H2OH_2O to prevent the spread of diseases like Malaria?

Solution:

Pouring oil creates a thin film on the surface of the H2OH_2O, which cuts off the supply of atmospheric O2O_2 to the mosquito larvae and pupae.

Explanation:

Since mosquito larvae breathe oxygen from the air through respiratory tubes, the oil layer acts as a barrier. Without O2O_2, the larvae cannot survive and die before reaching the adult stage.

Problem 2:

Identify the vector and the causative agent for the disease Malaria.

Solution:

Vector: Female Anopheles Mosquito; Causative Agent: PlasmodiumPlasmodium (a protozoan parasite).

Explanation:

The mosquito itself does not cause the disease; it acts as a carrier (vector) that transfers the PlasmodiumPlasmodium parasite into the human bloodstream during a bite.