A Treat for Mosquitoes
- A mosquito is a vector that carries infectious agents from an infected person to a healthy person.
- The diseases caused by mosquitoes are contagious and can be life-threatening.
- Mostly female mosquitoes are bloodsuckers. They lay eggs in stagnant water and spread deadly diseases.
- Dengue, malaria and chikungunya are some diseases spread by mosquitoes.
- Female mosquitoes have slender, elongated sucking mouth parts that help suck blood.
- The life cycle of mosquitoescomprises four stages: egg, larva, pupa and adult.
- The content given below is based on the chapter A treat for mosquitoes for NCERT class 5.
Diseases Caused by Mosquitoes and their Prevention
Question 1:
What Is a Pathogen?
Answer:
- Disease-causing organisms are called pathogens.
- It can be a fungus, a bacterium, a parasite etc.
- Pathogens can be treated with medicines.
Question 2:
What Is Epidemiology?
Answer:
- Epidemiology is the scientific study of the patterns and distribution of contagious diseases among a group of people.
- Epidemiology is important as it is related to public health.
- This type of study helps us to analyse the basic health needs of a population.
- It also helps us to determine the efficacy of certain medicines given to a particular population exposed to a specific disease.
Question 3:
Write Five Basic Characteristics of Insects.
Answer:
Five characteristic features of insects are:
- An insect's body is divided into three parts: head, thorax and abdomen.
- Insects have wings to fly.
- Insects have jointed body segments, and the legs of an insect are made up of several jointed parts.
- They have three pairs of legs and a pair of compound eyes.
- All insects have a pair of antennae at the top of their head.
Question 4:
Name a Few Vectors and Diseases Caused by Them, and Also Mention the Pathogens Responsible for Those Diseases.
Answer:
| Vector name | Disease name | Pathogens |
|---|---|---|
| Lice | Typhus | Bacteria |
| Sandflies | Sandfly fever or Leishmaniasis | Parasite |
| Tsetse flies | Sleeping sickness | Parasite |
| Ticks | Spotted fever | Bacteria |
Question 5:
State the Differences Between Anopheles, Aedes and Culex Mosquitoes.
Answer:
The differences between Anopheles sp, Aedes sp and Culex sp mosquitoes are as follows:
| Anopheles sp | Anopheles sp | Anopheles sp |
|---|---|---|
| They are active at night. | They are active during the daytime. | They are active both at night and day. |
| They lay boat-shaped eggs in water. | They lay spindle-shaped eggs in water. | They lay cylinder-shaped eggs in water. |
| Adults rest at an angular position. | Adults have black and white stripes on their bodies. | Adults rest parallel to the surface. |
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Question 6:
What is Zika fever?
Answer:
- Zika fever is an infectious disease caused by the zika virus.
- The primary carrier of this virus is Aedes spp. mosquitoes.
- A few common symptoms of Zika fever are muscle and joint pain, high fever with a headache, rashes all over the body, and conjunctivitis.
- Zika fever lasts for 7 to 10 days.
Question 7:
Name the Pathogens That Cause Malaria.
Answer:
Some malaria-causing pathogens are:
- Plasmodium falciparum
- Plasmodium vivax
- Plasmodium malariae
- Plasmodium ovale
- Plasmodium knowlesi
Question 8:
What Is Filariasis, and Which Mosquitoes Spread This Disease?
Answer:
- Filariasis is a tropical disease caused by a variant of thread-like roundworms.
- This disease causes swelling in the lymph nodes present under the arms and groin area. It also causes the thickening of the skin.
- Culex spmosquitoes carry the infectious parasites of this disease.
Question 9:
What Is West Nile Fever?
Answer:
Some malaria-causing pathogens are:
- It is an infectious disease caused by Culex sp mosquitoes. West Nile virus pathogen causes this disease.
- This flu-like disease is characterised by high temperature, nausea, vomiting and digestive issues.
- Prolonged infection due to West Nile fever can cause severe damage to the brain.
Life Cycle of a Mosquito
Question 1:
What Is a Respiratory Siphon?
Answer:
- A respiratory siphon is a long, slender tube-like organ that helps in respiration.
- The larval stage of mosquitoes has respiratory siphons that help in underwater breathing and respiration.
Question 2:
What Is the Function of Antennae?
Answer:
- This part of the insect body performs sensory functions like smelling, hearing and touching.
- Antennae help the insect to feel the movements in the air. Antennas are also sensitive to carbon dioxide gas, enabling them to locate their hosts.
Question 3:
What Is Japanese Encephalitis?
Answer:
Some malaria-causing pathogens are:
- It is a common disease spread by mosquitoes frequently in rural areas.
- It majorly affects farmers or those people who work in the agricultural fields.
- The symptoms of Japanese encephalitis are similar to cold and flu.
- It may cause severe brain swelling and disorientation with a high fever.
Question 4:
Which Types of Chemicals Are Used To Control Mosquitoes?
Answer:
- Some chemicals in the market kill mosquitos by damaging their nervous system or affecting them physically.
- They can be categorised as adulticides and larvicides, which help kill the mosquitoes at adult and larva stages, respectively.