Read the following passage and answer the questions that follow:
“Mosquitoes are drastically affecting the human health in almost all the developing tropical countries. Different species of mosquitoes cause very fatal diseases so much so that many humans lose their life and if they survive, are unable to put in productive hours to sustain their life. With the result, the health index of the country goes down.”
Why do the symptoms of malaria not appear in a person immediately after being bitten by an infected female {Anopheles}? Give one reason. Explain when and how the symptoms of the disease would appear.