Chapter 8: A Treat for Mosquitoes
मच्छरों की दावत? (मलेरिया, एनीमिया एवं रोनाल्ड रॉस)
Don't Let a 20-Minute Bubbling Delay Cost You CTET Qualification
In offline CTET exams, bubbling 150 bubbles takes 18 to 22 minutes of mechanical time. A single misaligned row can trigger an 8-question domino error. Practice bubble-filling this chapter's solved MCQs inside Mentora's official OMR simulator.
- Malaria is caused by the single-celled parasite Plasmodium and is transmitted exclusively by the female Anopheles mosquito (मादा एनाफिलीज़ मच्छर).
- Female Anopheles identification: Brownish body with spotted wings; feeds on blood to obtain protein to mature its eggs.
- Malaria symptoms: Shivering and rigors followed by recurring high fever (कंपकंपी के साथ बुखार).
- Cinchona tree bark (सिनकोना की छाल): Traditional Ayurvedic/tribal medicine boiled to cure malaria; modern quinine tablets are manufactured from it.
- Anemia (एनीमिया): Caused by a clinical deficiency of hemoglobin or iron in blood. Normal child range: 12 to 16 gm/dL. Prescribed diet: Amla (आंवला), Jaggery (गुड़), and Green Leafy Vegetables (हरी पत्तेदार सब्जियां).
- Ronald Ross (रोनाल्ड रॉस): British doctor born in Almora (Uttarakhand) who identified the malaria parasite in the stomach lining of female mosquitoes at Secunderabad hospital; awarded the Nobel Prize in Medicine in 1902.
- Mosquito prevention: Oil on stagnant water creates a surface tension film that blocks oxygen diffusion, suffocating mosquito larvae within hours.
- Trap: CBSE claims male mosquitoes bite and spread malaria. Correct: Male mosquitoes feed on plant juices and nectar; ONLY female Anopheles mosquitoes bite to nourish eggs.
- Trap: CBSE states normal hemoglobin is 8–10 gm/dL. Correct: Normal clinical hemoglobin is 12 to 16 gm/dL.
- Trap: CBSE claims apples or oranges are the primary cure for anemia. Correct: Amla, Jaggery (गुड़), and Green Leafy Vegetables (पालक, बथुआ) are the specific iron sources listed in NCERT.
NCERT Core Facts: Malaria, Anemia & Ronald Ross's Nobel Discovery
Chapter 8 examines mosquito-borne diseases (Malaria, Dengue, Chikungunya), nutritional anemia, and historical laboratory experimentation.
1. Malaria & The Cinchona Bark Remedy
- Carrier Vector: Malaria is spread only by the female Anopheles mosquito.
- Appearance: The female Anopheles looks brownish and features distinct dark spots on its wings.
- Key Symptoms: Severe cold shivering followed by alternating cycles of intense fever and profuse sweating (कंपकंपी और ठंड लगकर बुखार).
- Diagnosis: A finger prick of blood spread across a glass slide examined under a laboratory microscope to spot the Plasmodium parasite.
- The Cinchona Tree (सिनकोना का पेड़):
- From ancient times, the dried and powdered bark of the Cinchona tree was boiled in water to treat malaria patients.
- Today, purified Quinine tablets are mass-produced from this tree bark.
2. Anemia (एनीमिया) & The Iron-Rich Trio
In NCERT Class 5 EVS, schoolchildren Aarti and Rajat discuss their clinical pathology laboratory reports:
Clinical Facts on Anemia:
- Medical Cause: Anemia is caused by a low level of Hemoglobin (हीमोग्लोबिन) or Iron (लोहा) in the red blood cells.
- Normal Range: The normal clinical level of hemoglobin in children is 12 to 16 gm/dL (grams per deciliter).
- Physical Impacts: Decreases physical and mental stamina, reduces concentration in studies, and hinders proper physical growth.
- The Prescribed Iron-Rich Diet (High Frequency CTET Item!):
- a.Amla (आंवला) — Extremely rich in Vitamin C and iron.
- b.Jaggery (गुड़) — Natural unrefined sugarcane iron source.
- c.Green Leafy Vegetables (हरी पत्तेदार सब्जियां जैसे पालक, मेथी).
3. Ronald Ross & His Nobel Prize (1902)
- Ronald Ross spent years investigating whether mosquitoes spread malaria, encouraged by his mentor Dr. Patrick Manson.
- In August 1897 at a hospital in Secunderabad (Telangana), he spent months dissecting hundreds of mosquito species under a crude microscope:
"I dissected the stomach of a brownish, spotted mosquito. Under the microscope, I saw tiny dark spots in the stomach lining. I tested again, and found these identical parasites in the blood of malaria patients!"
- In December 1902, Ronald Ross was awarded the prestigious Nobel Prize in Physiology or Medicine for unraveling the transmission of malaria.
4. Mosquito Lifecycle & Preventive Measures
- Mosquitoes lay eggs in stagnant water; eggs hatch into tiny, grey, thread-like larvae (लार्वा) that swim actively.
- Oil Film Tactic (CBSE Item): Pouring a few drops of kerosene or vegetable oil over stagnant cooler water spreads a thin surface film. This film prevents atmospheric oxygen from reaching the breathing tubes of larvae, terminating them before they emerge as adult biting mosquitoes.
- Fish in Ponds: Releasing small fish (like Gambusia) into ponds controls mosquito populations because the fish actively consume mosquito larvae.
Test Your Mastery: A Treat for Mosquitoes
Authentic CBSE exam questions tested directly from this NCERT chapter.
A person with anemia is advised by a doctor to consume more of which of the following food groups?
किसी व्यक्ति को हीमोग्लोबिन की कमी (एनीमिया) है। डॉक्टर उसे निम्नलिखित में से किस खाद्य समूह को प्रचुर मात्रा में खाने की सलाह देगा?
Which of the following diseases is transmitted by mosquitoes?
निम्नलिखित में से कौन सा समूह मच्छरों द्वारा फैलने वाले रोगों का है?
Ronald Ross discovered the link between malaria and mosquitoes in which Indian city hospital?
रोनाल्ड रॉस ने 1902 में नोबेल पुरस्कार प्राप्त करने वाली खोज (मलेरिया और मच्छर का संबंध) किस भारतीय शहर के अस्पताल में की थी?
Which food items are rich in iron and recommended for anemia in CTET?
According to NCERT Class 5 EVS Chapter 8, the three primary iron-rich foods recommended to cure anemia are Amla (आंवला), Jaggery (गुड़), and Green Leafy Vegetables (हरी पत्तेदार सब्जियां).
What is the normal hemoglobin range for children mentioned in NCERT Class 5 EVS?
The normal hemoglobin range in human blood for children according to NCERT pathology reports is 12 to 16 gm/dL.
Why did Ronald Ross receive the Nobel Prize in Medicine in 1902?
Ronald Ross was awarded the 1902 Nobel Prize in Medicine for discovering that malaria is transmitted by the female Anopheles mosquito, identifying the parasite in its stomach lining at Secunderabad.