1. Life cycle of a mosquito
Lesson 5
Unit: Diseases
Mrs. Kalicharan

2. What does this picture show?

3. Adult mosquitoes
Adult mosquitoes lay their eggs on the surface of stagnant water.
Aedes aegypti which carries yellow fever, dengue and chikungunya prefers clean water.

4. Eggs - Larvae
Within a few days the eggs hatch into active larvae (wrigglers). These fed on microscopic organisms in the water.
The larvae breathe using air tubes which obtain atmospheric oxygen.
Their gills extract oxygen that is dissolved in the water.

5. Larvae- Pupae
They feed and grow for about a week or two and then change into pupae.
Pupae hangs from the surface of the water and breathe in air.
Inside the pupal case larval tissue are reorganised to form adult organs.
After a few days a young adult emerges.

6. Adult female mosquito
The mature female requires a meal of blood for her eggs to mature.
When she bites a human she secretes saliva which prevents blood from clotting.
If she bites an infected person she takes in pathogen in the blood.

7. Adult mosquito
The pathogen goes through a stage of its life cycle and enters the salivary glands of the mosquito.
When an infected mosquito bites a healthy person, saliva containing pathogens is injected into the person’s blood.

8. Life cycle of a mosquito

9. The four stages of a mosquito

10. Where each stage is found

11. Life cycle of a mosquito

12. Actual pictures of mosquito lifecycle

13. Exercise Draw and label each stage in the life cycle of a mosquito.
Follow the rules of biological drawings.
Include annotations indicating the habitat of each stage of the mosquito life cycle.
Lab report (practice SBA)- 10 marks.