Health, Diseases and Deficiency Disorders
Health, Diseases and Deficiency Disorders
Health gives 2 questions in the Part-III paper. Deficiency diseases are the most reliable block of marks in the whole biology section because they can be memorised from a single table, and the communicable-versus-non-communicable split carries the rest.
Components of Food
| Nutrient | Function | Sources |
|---|---|---|
| Carbohydrate | Provides energy | Rice, wheat, potato, sugar |
| Protein | Builds and repairs the body | Pulses, milk, eggs, fish, soya |
| Fat | Stores energy | Oil, butter, nuts |
| Vitamins | Protect the body | Fruits, vegetables |
| Minerals | Support body functions | Milk, leafy vegetables, salt |
| Roughage | Aids digestion | Whole grain, fruit and vegetable fibre |
| Water | Transport and temperature | Drinking water, fruits |
Carbohydrates and fats are energy-giving, proteins are body-building, and vitamins and minerals are protective. A balanced diet contains all of them in the right proportion, and roughage is included though it provides no nutrient at all — a point asked directly.
Deficiency Diseases
| Nutrient | Deficiency disease | Main symptom |
|---|---|---|
| Vitamin A | Night blindness | Poor vision in dim light |
| Vitamin B1 | Beriberi | Weak muscles, little energy |
| Vitamin C | Scurvy | Bleeding gums, slow healing |
| Vitamin D | Rickets | Soft, bent bones |
| Calcium | Bone and tooth decay | Weak bones and teeth |
| Iron | Anaemia | Weakness, pale appearance |
| Iodine | Goitre | Swelling of the neck |
| Protein | Kwashiorkor, marasmus | Stunted growth, wasting |
Vitamin D is made in the skin with sunlight, so its deficiency is about exposure as much as diet. Vitamins A, D, E and K are fat-soluble while B and C are water-soluble, which is why the water-soluble ones must be taken regularly and are lost in overcooking.
✗ Scurvy is caused by a deficiency of vitamin D | ✓ Scurvy comes from lack of vitamin C; vitamin D deficiency causes rickets
Communicable and Non-Communicable Diseases
| Point | Communicable | Non-communicable |
|---|---|---|
| Spreads | Yes, person to person or by a carrier | No |
| Cause | Microorganisms | Lifestyle, deficiency, heredity |
| Examples | Tuberculosis, malaria, cholera, influenza | Diabetes, hypertension, cancer, anaemia |
| Prevention | Hygiene, vaccination, vector control | Diet, exercise, early detection |
Vaccination works by introducing weakened or dead microbes so that the body makes antibodies and is protected in advance. India's routine immunisation covers diseases such as polio, tuberculosis, measles, diphtheria, tetanus and hepatitis B, and smallpox has been eradicated worldwide through vaccination.
Public Health in Practice
- Safe drinking water, sanitation and handwashing prevent most waterborne disease.
- Vector control — removing stagnant water — is the main defence against malaria and dengue.
- Iodised salt prevents goitre; it is the cheapest public-health measure in the list.
- A mid-day meal in school addresses both hunger and micronutrient deficiency.
- First aid, clean toilets and clean drinking water are school-level responsibilities.
The school angle is not incidental. A middle-school teacher is expected to notice signs of malnutrition, encourage handwashing and manage the mid-day meal, and a teaching paper can frame a health question in exactly that setting.
विटामिन A, D, E, K वसा में घुलनशील हैं; B और C पानी में।
TRE pointer: The deficiency table is the single highest-return half-page in the biology block and it is asked every year in some form. The fat-soluble versus water-soluble split is the discriminator that separates prepared candidates. Because you are being recruited to teach classes 6 to 8, expect a health question framed around a school — the mid-day meal, handwashing, or spotting anaemia in a pupil. With −1/3 negative marking, this table should be secured completely.
60-Second Recap
- Carbohydrates and fats give energy, protein builds, vitamins and minerals protect.
- Roughage provides no nutrient but is essential for digestion.
- Vitamin A night blindness, B1 beriberi, C scurvy, D rickets.
- Iron deficiency causes anaemia; iodine deficiency causes goitre.
- A, D, E and K are fat-soluble; B and C are water-soluble and lost in overcooking.
- Communicable diseases spread; diabetes and hypertension do not.
Frequently Asked Questions
Which vitamins are fat-soluble?
Vitamins A, D, E and K are fat-soluble and can be stored in the body. Vitamins B and C are water-soluble, are not stored, and are lost when food is overcooked or when the cooking water is discarded, so they must be taken regularly in the diet.
What causes goitre and how is it prevented?
A deficiency of iodine, which the thyroid gland needs to make thyroxine. Without enough of it the gland swells, causing goitre. Using iodised salt prevents it entirely, which makes it one of the simplest and cheapest public-health measures available.
What is the difference between communicable and non-communicable diseases?
Communicable diseases are caused by microorganisms and spread from person to person or through a carrier, as with tuberculosis and malaria. Non-communicable diseases such as diabetes and hypertension arise from lifestyle, deficiency or heredity and do not spread between people.
Why is roughage part of a balanced diet if it has no nutrients?
Because it adds bulk to food and helps it move through the digestive system, preventing constipation. It is obtained from whole grains and the fibrous parts of fruits and vegetables. Being included despite providing no nutrient is exactly why it is asked.