Selina Concise Solutions for ICSE Class 6 Biology Chapter 7 Health and Hygiene

Health and Hygiene

Multiple Choice questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

(a) Malaria is caused by:
(i) Bacteria
(ii) Protozoan
(iii) Fungi
(iv) Virus
Answer: (ii) Protozoan
Malaria is a serious disease that enters the human body through the bite of an infected mosquito. The specific protozoan responsible for this is called Plasmodium.
Teacher's Tip: Remember "M-P" for Malaria-Protozoan.
Exam Tip: Mentioning that it is spread by the female Anopheles mosquito helps you get extra credit.

(b) Deficiency of calcium causes
(i) Poor growth of teeth and gums
(ii) Goitre
(iii) Anaemia
(iv) Polio
Answer: (i) Poor growth of teeth and gums
Calcium is the main mineral that makes our bones and teeth hard and strong. Without enough calcium, children may develop weak bones and dental problems.
Teacher's Tip: Think of Calcium as the "bricks" for your skeleton.
Exam Tip: When writing about calcium, always link it to "bone and tooth health" for clarity.

(c) Hay fever and asthma are
(i) Deficiency diseases
(ii) Genetic diseases
(iii) Organic diseases
(iv) Allergy diseases
Answer: (iv) Allergy diseases
These conditions occur when the body overreacts to harmless substances like pollen or dust. This reaction can cause difficulty in breathing or persistent sneezing.
Teacher's Tip: Allergies are like "false alarms" in your immune system.
Exam Tip: Use the term "hypersensitivity" to define allergy diseases in your descriptive answers.

PQ: Cataract is a disease of:
(i) Ears
(ii) Nose
(iii) Eyes
(iv) Throat
Answer: (iii) Eyes
Cataract causes the clear lens of the eye to become cloudy, which leads to blurry vision. It is common in older people and can usually be fixed with a simple surgery.
Teacher's Tip: Imagine trying to look through a foggy window; that is what a cataract feels like.
Exam Tip: Remember that cataracts affect the "lens" specifically when asked for details.

(d) Infectious diseases can be prevented by:
(i) Medicines
(ii) Proper food
(iii) Immunisation
(iv) Exercise
Answer: (iii) Immunisation
Immunisation involves giving vaccines that train our immune system to recognize and fight specific germs. This prevents us from getting sick even if we are exposed to the disease later.
Teacher's Tip: Vaccines are like "training drills" for your white blood cells.
Exam Tip: Always list "vaccination" as the primary method for preventing communicable diseases.

(e) Which one of the following is a genetic disease?
(i) Scurvy
(ii) Leukemia
(lii) Goitre
(iv) Haemophilia
Answer: (iv) Haemophilia
Genetic diseases are passed down from parents to children through DNA. Haemophilia is a condition where the blood does not clot properly after an injury.
Teacher's Tip: Genetic diseases are "family traits" that happen to be illnesses.
Exam Tip: Be careful not to confuse nutritional diseases (like Scurvy) with genetic ones.

(f) Which one of the following is a degenerative disease?
(i) Thalassemia
(ii) Ben-ben
(iii) Cataract
(iv) Diabetes
Answer: (iii) Cataract
Degenerative diseases happen when organs or tissues slowly wear out due to aging or lack of use. Cataract is a perfect example because the eye lens changes as a person grows older.
Teacher's Tip: Think of "Degenerative" as "Wearing Out" over time.
Exam Tip: Aging is the most common cause of degenerative conditions, so mention it in your definitions.

(g) Pellagra is one disease caused by the deficiency of:
(i) Vit. B3
(ii) Vit. B1
(iii) Vit. C
(iv) Vit. D
Answer: (i) Vit. B3
Pellagra is a disease that affects the skin, digestion, and even the brain when someone doesn't get enough Niacin (Vitamin B3). It was once common in populations that ate mostly corn-based diets.
Teacher's Tip: B3 is "Niacin" - think of "Nice skin" because B3 keeps skin healthy.
Exam Tip: Remember the "4 Ds" of Pellagra: Diarrhea, Dermatitis, Dementia, and Death.

(h) Deficiency of Iodine in one’s food can cause:
(i) Ben-ben
(ii) Goitre
(iii) Scurvy
(iv) Pellagra
Answer: (ii) Goitre
Goitre is the swelling of the thyroid gland in the neck because it is trying too hard to work without iodine. Using iodized salt in daily cooking is the easiest way to prevent this.
Teacher's Tip: Iodine is the fuel for your thyroid gland.
Exam Tip: Associate "Neck Swelling" immediately with Iodine deficiency and Goitre.

(i) Which one of the following mineral deficiency diseases can be cured by eating a diet which include green leafy vegetables, banana, cereals, egg-yolk?
(i) Goitre
(ii) Anaemia
(iii) Brittle bones
(iv) Pain in muscle contraction
Answer: (ii) Anaemia
These foods are rich in iron, which is needed to make the red pigment called haemoglobin in our blood. Anaemia makes a person feel very tired and look pale because of low oxygen in the body.
Teacher's Tip: Iron is like a magnet for oxygen in your red blood cells.
Exam Tip: Always list "Green leafy vegetables" as a top source for iron to combat Anaemia.

(j) Which one of the following vitamin deficiency diseases can be cured by eating a diet which includes carrot, yellow fruits, vegetables, butter, milk, fish ?
(i) Beri-beri
(ii) Dermatitis
(iii) Night blindness
(iv) Scurvy
Answer: (iii) Night blindness
Vitamin A is essential for healthy eyes and helps us see in dim light. Carrots are famously good for your eyes because they contain a lot of beta-carotene which the body turns into Vitamin A.
Teacher's Tip: "A" is for "Eyes" - Vitamin A keeps your vision sharp.
Exam Tip: If the question mentions "yellow fruits," think Vitamin A and Night Blindness.

(k) Which one of the following is a communicable disease?
(i) Measles
(ii) Cancer
(iii) Heart stroke
(iv) Allergy
Answer: (i) Measles
Communicable diseases are those that can spread from an infected person to a healthy person through the air or touch. Measles is a highly contagious virus that causes a red rash and fever.
Teacher's Tip: Communicable = "Can be shared" with others.
Exam Tip: Always check if a disease is caused by a germ (virus/bacteria) to see if it is communicable.

Short Answer Questions:

Question : What is a non-communicable disease ?
Answer:
The diseases which are caused due to improper functioning of the body organs e.g. diabetes, heart attack. They are not caused by germs and not transmitted from one to another.
These diseases are often called lifestyle diseases because they are linked to how we live and eat. Unlike the flu, you cannot catch a heart condition just by sitting next to someone.
Teacher's Tip: Non-communicable means "No Catching" - it stays with only one person.
Exam Tip: Always give at least two examples like Diabetes or Goitre when defining this term.

Question : What is a deficiency disease
Answer:
These disease are caused by lack of nutrients, vitamins, minerals as a anaemia, goitre.
When our diet doesn't have enough of a specific nutrient for a long time, the body starts to malfunction. These diseases are easily cured simply by eating the right healthy foods.
Teacher's Tip: Think of deficiency as a "Missing Ingredient" in your body's recipe.
Exam Tip: Specify which nutrient is missing (e.g., Vitamin C for Scurvy) to show deeper understanding.

Question : What are communicable diseases ? How can they be avoided ?
Answer:
Those disease which spread from one person to another by the entry of microorganisms are known as communicable diseases. The disease-causing germs are called Pathogens. These disease can be avoided by proper vaccination, healthy food and hygenic surroundings.
These diseases travel through coughing, sneezing, or sharing personal items with a sick person. Keeping your hands clean and staying away from stagnant water are the best ways to stop them from spreading.
Teacher's Tip: Communicable diseases are "Germ Travelers".
Exam Tip: Use the word "Pathogens" to describe the germs to sound like a science expert.

Question : Biting nails should be strictly avoided. Give reason.
Answer:
Nail biting may cause many disease as the dirt has many bacteria causing diseases. Nails should be cut from time to time to save from diseases.
Our fingernails act like tiny shovels that collect germs and dust as we touch things throughout the day. When you bite them, you are basically swallowing those harmful germs directly into your stomach.
Teacher's Tip: Nails are "Germ Traps" - keep them short and clean!
Exam Tip: Mention that dirt contains "pathogenic microbes" as a more scientific reason.

Question : Regular exercise and proper rest is a must. Give reason.
Answer:
Regular exercise keeps our body strong and immune to many diseases, rest refreshes our body.
Exercise helps the blood flow better and keeps your muscles and heart in great shape. Rest is equally important because it is the only time the body can repair its cells and recharge its energy.
Teacher's Tip: Exercise is "Body Power" and Sleep is "Body Repair".
Exam Tip: Mention that exercise improves "blood circulation" to get full marks.

Question : Children eating more of fast food tend to suffer from obesity (overweight). Comment.
Answer:
Fast food like pizza, burger, patty, oily foods etc. have much carbohydrates and fats. Children eating these become more and more fat and gain weight soon as they do not do much of physical work.
These foods are very high in calories but very low in vitamins and fiber that our body needs. If we eat more energy than we use up, our body stores that extra energy as body fat.
Teacher's Tip: Fast food is "Junk" because it's mostly filler with no real value.
Exam Tip: Define "Obesity" as an excessive accumulation of body fat for a precise answer.

Question : How can we control spreading of diseases by mosquitoes and houseflies ?
Answer:
We can control spreading of diseases by mosquitoes and houseflies by using repellants, throwing garbage in covered bins, avoiding stagnation of water and checking breeding of these insects.
Mosquitoes need still water to lay their eggs, so clearing out old tires or buckets stops them from growing. Houseflies are attracted to open food and waste, so keeping things covered keeps them away from our meals.
Teacher's Tip: No water + No garbage = No bugs!
Exam Tip: Mentioning "insecticides" or "mosquito nets" as additional measures is always good.

2. Name the following:
 

(a) A bacterial disease caused due to contaminated water
Answer: Cholera.
Cholera is an infection of the small intestine that causes severe diarrhea and dehydration. It is usually found in water that has been mixed with sewage or waste.
Teacher's Tip: Always boil water if you aren't sure it's clean!
Exam Tip: Be sure to distinguish between bacterial (Cholera) and viral (Hepatitis A) water diseases.

(b) A disease caused due to Plasmodium
Answer: Malaria.
Plasmodium is a tiny protozoan parasite that lives inside the stomach of mosquitoes before moving into humans. It is one of the most common tropical diseases in the world.
Teacher's Tip: Plasmodium is the "Passenger" in the mosquito "Bus".
Exam Tip: Write "Plasmodium vivax" if you want to show you know the specific species.

(c) A disease caused due to the bite of female Culex mosquito
Answer: Elephantiasis.
This disease causes extreme swelling of the legs and arms because the parasite blocks the body's fluid drainage system. It is also known as lymphatic filariasis.
Teacher's Tip: Culex mosquito is different from the Malaria mosquito (Anopheles).
Exam Tip: Note that "Filarial worms" are the actual cause, and the mosquito is just the carrier.

(d) A viral disease spread by the bite of a dog
Answer: Rabies/ Hydrophobia.
Rabies is a deadly virus that attacks the brain and nervous system of mammals. Hydrophobia means "fear of water," which is a famous symptom of this disease in humans.
Teacher's Tip: Always get a vaccine immediately if bitten by a stray animal.
Exam Tip: Use both names "Rabies" and "Hydrophobia" to show your complete knowledge.

(e) Two diseases caused due to deficiency of protein in the diet of a child.
Answer: Kwashiorkor and marasmus.
Kwashiorkor causes a swollen belly, while Marasmus makes the child look extremely thin and bony. Both are caused by severe malnutrition and lack of energy-rich foods.
Teacher's Tip: Kwashiorkor = Big belly; Marasmus = Skin and bone.
Exam Tip: Remember these are grouped under "PEM" (Protein Energy Malnutrition).

(f) Any three water-borne disease.
Answer: Amoebiasis, Cholera, Hepatitis A.
These diseases enter the body when we drink water that contains harmful microbes. They usually cause stomach pain, fever, and digestive problems.
Teacher's Tip: Water-borne = "The water carried it to you".
Exam Tip: List them clearly with commas to make the answer easy to read.

(g) A viral disease caused due to unhealthy sexual contact
Answer: AIDS.
AIDS stands for Acquired Immune Deficiency Syndrome and is caused by the HIV virus. It weakens the body's ability to fight off even simple infections like a cold.
Teacher's Tip: HIV is the virus, and AIDS is the condition it causes.
Exam Tip: Always write out the full form of the virus (HIV) if asked for the cause.

(h) A disease caused due to choking of coronary artery
Answer: Atherosclerosis.
This happens when fat and cholesterol build up inside the arteries that feed the heart muscle. Over time, this blockage can lead to chest pain or even a heart attack.
Teacher's Tip: Coronary arteries are the "power lines" for the heart muscle.
Exam Tip: Associate "artery choking" with "Atherosclerosis" for your one-word answers.

3. Write short (1-2 sentences) notes on the following: Disease, immunisation, pathogen, allergy, AIDS.
Answer:
1. Disease: Disease is a departure from normal health due to structural or functional disorder of the body. Disease may be due to deficiency of nutrients or malfunctioning of organs or genetic disorders, improper metabolic activity, or allergies, or cancer and mental illness as diabetes, haemophilia, leukemia, schizophrenia.
2. Immunisation: It means, we make the body immune to certain diseases by introducing respective weakened germs into the body. Thus we develop resistance to the concerned disease this process is called immunisation. The germs or the material introduced into the body to make it resistant to the concerned disease is called vaccine. This produces antibodies in the body of the person and the person can be saved by these antibodies. The vaccine can be given by the injection or orally as polio drops, tap vaccine for typhoid, BCG vaccine for tuberculosis.
3. Pathogens: The germs that cause diseases to human beings and to other animals and plants are called pathogens. They spread the diseases from person to person or through the air or through the articles of the diseased persons. Pathogens may be different kinds of bacteria, viruses, fungi, protozoans or worms.
Allergy: Allergy is an unpredictable reaction to a particular substance. This type of substance is called allergen. Different people are allergic to different substances. A few common allergens are dust, spores, pollen, certain clothes, particular cosmetics, etc. The common areas of the body parts which are affected by allergies are skin, respiratory and digestive tracts. Asthma, eczema, diarrhoea, vomiting, nausea, etc. are some of the common allergic reactions.
4. AID’S (Acquired Immune Deficiency Syndrome): It is a viral disease caused by the virus called HTV (Human immuno deficiency virus) This virus makes the defence mechanism of the human body veiy weak. The immune system in the body as W.B.C. becomes weak. Thus the person catches the infectious diseases very easily. This disease spreads through sexual contact as one of the partner may be carrier of the disease. It may spread through the blood transfusion and infected syringes, blades of the barbers, it may infect the developing baby through the blood by the mother. It is very deadly disease.
These definitions help us understand the wide world of health, from how germs attack to how our body protects itself. Knowing about things like allergies and immunisation helps us make better choices for our health every day.
Teacher's Tip: Break down the word "Immunisation" - it means making someone "Immune" (safe).
Exam Tip: For AIDS, remember to mention both the virus (HIV) and the effect on the immune system (weakening WBCs).

4. Fill in the blanks by selecting suitable words given below: (clotting, goitre, insuline, rickets, iron, proteins)
1. Anaemia is caused due to the deficiency of iron
2. Deficiency of Vit. D causes rickets in children.
3. Deficiency of iodine in the diet may cause goitre.
4. Kwashiorkor is caused due to the deficiency of proteins
5. Diabetes is caused due to undersecretion of insulin.
6. Haemophilia is a disease caused due to slow clotting of the blood.
Answer: (As filled in above)
These blanks highlight the most common nutritional and hormonal problems found in humans. Each word represents a missing "piece" that the body needs to stay balanced and healthy.
Teacher's Tip: Iron is for blood, Iodine is for the neck, and Insulin is for sugar!
Exam Tip: Be careful with the spelling of "Insulin" - it does not have an 'e' at the end in most science books.

5. Find the odd one out:
 

(a) Typhoid, cholera, jaundice, tuberculosis, tetanus.
Answer: Jaundice is odd one.
While the others are specific bacterial infections, jaundice is a symptom that happens when the liver is not working correctly. It makes your skin and the whites of your eyes look yellow.
Teacher's Tip: Jaundice is a "Sign" of a problem, not the name of a germ.
Exam Tip: Always give the reason for your choice to ensure full marks in "Odd One Out" questions.

(b) Cold, malaria, measles, mumps.
Answer: Malaria is odd one.
Cold, measles, and mumps are all caused by viruses that spread through the air. Malaria is different because it is caused by a protozoan and needs a mosquito to travel.
Teacher's Tip: Malaria is "Vector-borne" (needs a bug), while the others are "Air-borne".
Exam Tip: Grouping by the "causal organism" (virus vs. protozoan) is a strong scientific reason.

(c) Scurvy, rickets, polio, pellagra, nightblindness.
Answer: Haemophilia is odd one.
(Note: The textbook answer provided is 'Haemophilia', though it wasn't in the list above. It refers to the fact that Polio is a viral disease, while the others are deficiency diseases.)
Scurvy, rickets, pellagra, and nightblindness can all be cured with a better diet. Polio is caused by a virus and can only be prevented by getting vaccinated.
Teacher's Tip: Deficiency = Lack of food; Polio = Germ attack.
Exam Tip: If the question mentions Haemophilia, it is odd because it is "Genetic," whereas the others are "Nutritional."

(d) Proteins, carbohydrates, fats, minerals, cancer. ‘
Answer: Cancer is odd one.
Proteins, carbs, fats, and minerals are all nutrients that our body needs to stay healthy. Cancer is a disease where cells grow out of control and is not a nutrient.
Teacher's Tip: Nutrients are "Building Blocks"; cancer is a "Breakdown" of the system.
Exam Tip: Classify words into "Nutrients" vs. "Diseases" to find the odd one quickly.

6. Fill in the blank in the following table:
Answer:
(a) Vitamin A: Name of deficiency: Night blindness; Source: Carrot, fish milk, yellow fruits; Function: Growth of hair, skin.
(b) Vitamin $B_{1}$: Name of deficiency: Beri-beri; Source: Eggs, nuts, legume; Function: Carbohydrate metabolism.
(c) Ascorbic acid (Vitamin C): Name of deficiency: Scurvy (bleeding gums); Source: Citrus fruits, tomatoes; Function: Develops immunity.
(d) Vitamin D: Name of deficiency: Rickets (in childhood) bones turn soft; Source: Sun light, milk, butter, fish liver oil, egg yolk; Function: Controls calcium, phosphorus metabolism.
This table summarizes how vitamins act as small but powerful regulators of our health. Knowing which foods to eat can prevent very painful conditions like scurvy or soft bones.
Teacher's Tip: Citrus fruits (lemons/oranges) are the "Vitamin C Kings".
Exam Tip: Use the chemical names like "Ascorbic acid" to impress your teacher on the answer sheet.

7. Given below is a crossword puzzle. Read the clues across and clues down, and fill up the blank squares. Check up your performance with the correct solution given at the end.
Clues across:
1. Category of pathogen that causes diseases, like common cold and mumps.
5. This is the vaccine for preventing tuberculosis.
6. An organ usually affected by tuberculosis.
7. Jumbled spelling of one of the most common insect which visits our exposed foods and contaminates them.
8. Cover this part of your body by a handkerchief while sneezing to prevent droplet infection to others.
9. These may readily grow in your hair, if you do not wash it regularly.
10. A disease that weakens body’s defence system against infections.
Clues down:
1. Germ or germ-substance introduced into the body to prevent occurrence of an infectious disease.
2. A disease caused by an infected dog, and which affects the central nervous system.
3. A disease in which the eyes, the skin and the urine turn yellow.
4. The disease pertussis is popularly known as whooping
Answer:
ACROSS: 1. VIRUS, 5. BCG, 6. LUNG, 7. HOUSEFLY (IES), 8. NOSE, 9. LICE, 10. AIDS.
DOWN: 1. VACCINE, 2. RABIES, 3. JAUNDICE, 4. COUGH.
Solving crosswords is a fun way to test if you remember all the new scientific words we've learned. It forces you to think about the exact spelling and meaning of every health term.
Teacher's Tip: Practice the spelling of "Jaundice" and "Vaccine" as they are tricky!
Exam Tip: For clues about TB (tuberculosis), always think of "BCG" and "Lungs".

Long Answer Questions

Question 1: Describe the ways in which communicable diseases are transmitted through various indirect methods.
Answer:
Indirect methods of transmission of communicable diseases:
1. Using items used by the infected persons: The healthy persons may be infected by using the articles like towel, hankey, utensils, bedding used by the patient infected by the communicable diseases. Diseases like tuberculosis, ring worm, common cold, influenza are transmitted by this method.
2. Contaminated food and water: Diseases like dysentery, cholera spread through the contaminated food and water. Flies sitting on the food, if taken by a healthy person may be infected by the germs which may cause vomiting and loose motions. Similarly water and food infected by entamoeba may cause dysentery to persons who may take contaminated food.
3. Vectors or carriers: Organisms like mosquitoes and house flies, ticks carry germs from the source of infection and pass on the germs to the normal persons and thus they are infected by diseases like malaria, cholera, plague. These organisms which cany the disease are called vectors and are not infected themselves. Mosquitoes suck blood and carry the disease causing protozoans from infected persons to healthy persons. Similarly houseflies carry the germs from garbage and sewage to the food. If this food is taken by the persons they become prey to typhoid and other diseases.
4. Air: One sneeze from a person infected by cold may give billions of germs which are carried by air and may infect the healthy person. Tuberculosis passes from one person to other by coughing or sneezing of the infected person. These germs remain suspended in the air and persons may be infected by these spores or germs. Common cold, measles, diptheria, chicken pox.
Understanding how diseases travel helps us set up defenses to stop them. Simple habits like washing your hands and covering your food make a huge difference in staying healthy.
Teacher's Tip: Think of indirect transmission as "The Germ took the Bus" (where the bus is a fly, a towel, or the air).
Exam Tip: Always categorize your long answer into sections like "Food/Water," "Air," and "Vectors" to be clear.

Question 2: List 3 ways by which you should keep your environmentclean.
Answer:
We should keep our environment clean in following ways:
1. Maintain a clean environment to prevent the spreading of diseases due to the breeding of mosquitoes, house flies and microorganisms.
2. Garbage should be kept in covered bins so that flies do not breed on it.
3. Do not allow water to stagnate outside your house and in your neighbourhood. All the drains should also be covered. This will prevent breeding of mosquitoes.
A clean environment acts like a shield that protects the whole community from sickness. When we manage our waste properly, we remove the "homes" of harmful pests like flies and mosquitoes.
Teacher's Tip: "Cleanliness is next to Godliness" - and it keeps the doctor away too!
Exam Tip: Mentioning "stagnant water" is a key point for any question about environment and health.

Question 3: cine’s are prepared, giving the name of one disease for which each type of vaccine is used.
Answer:
For developing resistance in the body we introduce germs or germ substances in the body to develop resistance in the body against a particular disease. The material introduced into the body is called vaccine, this practice is called prophylaxis. The germ or the germ substance is put into the body orally as polio drops or it is introduced by injection as TAB vaccine. Vaccine or vaccination was attached with small pox, but it is now used in a general sense.
Preparation:
1. Killed germs: are introduced into the body These act as vaccine for TAB, vaccine for typhoid, Salk’s vaccine for poliomyelitis. Rabies vaccine for dog bite.
2. Living weakened germs: The living germs are treated in such a way that they become very weak and as such, they cannot cause the disease. They can induce antibody formation such as the vaccine for measles and the freezed dried BCG vaccine for tuberculosis.
3. Living fully virulent germs: These virulent germs in small doses are introduced into the body as vaccine and these produce antibodies in the body and these do not allow the germs of particular type to cause that disease. In this vaccination the person is inoculated with cowpox virus. It is very similar to small pox virus.
4. Toxoids: Toxoids are prepared from the extracts of toxins secreted by bacteria. These toxins are poisons and these are made harmless by adding formalin into them. They retain their capacity and as a result when introduced into the body they produce antibodies into the body and do not allow the germs to grow in the body as vaccines for diphtheria and tetanus.
Vaccines are a miracle of science that help our body fight enemies without ever getting truly sick first. By using weakened or dead germs, we give our immune system a "safe practice round" before a real attack happens.
Teacher's Tip: Prophylaxis is just a fancy science word for "Prevention".
Exam Tip: Learn the difference between "Killed germs" and "Toxoids" for high-scoring technical answers.

ADDITIONAL QUESTIONS

I. Multiple choice questions. Tick (✓) the correct choice:

1. Which of the following is a disease caused by bacteria?
(a) cholera
(b) AIDS
(c) malaria
(d) rabies
Answer: (a) cholera
Bacteria are tiny single-celled organisms that can multiply very fast in contaminated food. Cholera is a prime example of a disease where these bacteria release toxins in your gut.
Teacher's Tip: Most water-borne stomach diseases are caused by bacteria.
Exam Tip: Remember: Cholera = Bacteria, Malaria = Protozoa, AIDS = Virus.

2. Which of the following is not a viral disease?
(a) pneumonia
(b) measles
(c) polio
(d) rabies
Answer: (a) pneumonia
While some types of pneumonia can be viral, the most common and classic type is caused by bacteria. Measles, polio, and rabies are strictly caused by specific viruses.
Teacher's Tip: Pneumonia is an infection of the lungs that can have many causes, but usually, it's bacterial.
Exam Tip: If you see "polio" or "measles," immediately think "Virus."

3. Ringworm is a disease caused by
(a) protozoa
(b) bacteria
(c) virus
(d) fungi
Answer: (d) fungi
Despite its name, ringworm is not caused by a worm; it is a fungal infection of the skin. It gets its name because it often creates a red, itchy, circular (ring-shaped) rash.
Teacher's Tip: "Ring-worm" is a "Ring-fungus" - don't be fooled by the name!
Exam Tip: Always associate skin rashes like athletes foot or ringworm with Fungi.

4. Kwashiorkor is caused by
(a) smoking
(b) worms
(c) virus
(d) imbalance in diet
Answer: (d) imbalance in diet
Specifically, a diet that is high in calories but very low in protein leads to this condition. This imbalance prevents the body from growing muscles and repairing tissues correctly.
Teacher's Tip: Balanced Diet = Health; Imbalanced Diet = Deficiency.
Exam Tip: If "protein deficiency" isn't an option, "imbalance in diet" is the next best answer.

II.Fill in the blanks:
1. Over-eating causes a disease called obesity.
2. Food poisoning is caused by bacteria.
3. One of the diseases caused by protozoa is malaria.
Answer: (As filled in above)
These simple blanks connect activities or organisms directly to their medical results. For instance, too much food intake leads to obesity, while bad bacteria in food leads to poisoning.
Teacher's Tip: "Proto-zo-a" sounds like "Zoo" - and the malaria parasite is a tiny animal-like microbe.
Exam Tip: When filling in "bacteria" for food poisoning, you can also write "Salmonella" to show off your knowledge.

III. Find the odd one out, giving reason:

1. Pneumonia, cholera, leprosy, measles
Answer: Measles: Measles is the odd-one out as it a disease caused by a vims while the rest three are bacterial diseases.
Pneumonia, cholera, and leprosy are all treated with antibiotics because they are bacterial. Viruses, like the one that causes measles, do not respond to antibiotics at all.
Teacher's Tip: Bacteria vs. Virus is the most common way to group these!
Exam Tip: Make sure you state that the others are "Bacterial" to complete your reasoning.

IV. Define the following: 1. Diseases 2. Malnutrition
Answer:
1. Diseases: Any disorder or abnormal working of an organ, part or system of the body leads to illness called as disease.
2. Malnutrition: The condition of nutrition in which the food is either in inadequate quantity or in excess or it lacks in some essential nutrient is called malnutrition.
These terms describe a state where the body is not at its best "baseline" health. Malnutrition is especially interesting because it includes both eating too little (undernutrition) and eating too much (overnutrition).
Teacher's Tip: "Mal-" means "Bad," so Malnutrition is just "Bad Nutrition".
Exam Tip: Define malnutrition as "inadequate OR excessive" to show it works both ways.

V. Name the following:
 

Question 1: Two diseases each caused by bacteria, protozoa and virus.
Answer:
Two diseases caused by bacteria are pneumonia and cholera. Two diseases caused by protozoa are malaria and amoebiasis. Two diseases caused by vims are chicken pox and AIDS.
Grouping diseases by their causes is the first step in learning how to treat them. Doctors need to know if they are fighting a virus or a bacteria before they can give the right medicine.
Teacher's Tip: Think of the "Big Three" invaders: Bacteria, Virus, Protozoa.
Exam Tip: Practice writing these in a small table to keep the different types organized in your head.

Question 2: Organism which causes malaria.
Answer: Protozoa (called Plasmodium).
While the mosquito carries the disease, the Plasmodium is the actual organism that makes us sick. It enters our red blood cells and multiplies until they burst.
Teacher's Tip: Mosquito = Carrier; Plasmodium = Culprit.
Exam Tip: Always use the word "Plasmodium" when asked for the specific organism.

Question 3: Cause of obesity.
Answer: Excess of food (overnutrition).
Obesity happens when we regularly consume more calories than our body burns for energy. This extra energy gets stored as fat, which can eventually put a strain on the heart and joints.
Teacher's Tip: "O" in Obesity stands for "Over-eating".
Exam Tip: Mention "lack of physical activity" as a secondary cause for a more complete answer.

VI. Answer the following questions :
 

Question 1: List the causes of diseases.
Answer:
Diseases develop due to a number of causes such as:
1. Imbalances in the diet.
2. Infection by micro-organisms.
3. Malfunctioning of body organs.
4. Allergic reactions to substances in the environment.
5. Social factors such as smoking, alcoholism, drug addiction, unhealthy life style.
This list shows that illness isn't just about "catching a germ." Many diseases come from our own choices, our environment, or even our family history.
Teacher's Tip: Think of disease causes as "Inside" (organs), "Outside" (germs), and "Lifestyle" (habits).
Exam Tip: Providing all five points in your answer ensures you get maximum marks for "Listing" questions.

Question 2: What are deficiency diseases?
Answer: The diseases caused by inadequate intake of food or the lack of some essential nutrient in our diet are called deficiency diseases
These are the most "preventable" diseases because they can be cured by simply eating a balanced diet. If we make sure our plate has proteins, vitamins, and minerals, we won't face these issues.
Teacher's Tip: "Deficient" means "Not enough".
Exam Tip: Always give an example (like Scurvy or Night Blindness) to support your definition.

Question 3: Differentiate between undermutrition and malnutrition.
Answer:
undermutrition
1. It is a condition of nutrition where food isinad equate.
2. It leads to deficiency diseases.
3. Under mutrition is a form of malnutrition
Malnutrition
1. It is condition of nutrition where food is either inade-uate, or excess or lacks some essential nutrient.
2. It leads to deficiency diseases and obesity.
3. Malnutrition has many forms like under mutrition, over-nutrition or imbalance of nutrients in diet.
Undernutrition is strictly about not getting enough to eat, which leads to starvation or wasting. Malnutrition is a broader term that also includes eating too much junk food or having the wrong balance of nutrients.
Teacher's Tip: All undernutrition is malnutrition, but not all malnutrition is undernutrition!
Exam Tip: Remember: Undernutrition = "Too Little"; Malnutrition = "Bad Balance".

DEFICIENCY DISEASES

I. Multiple choice questions. Tick (✓) the correct choice:

1. Kwashiorkor is a disease caused by
(a) microbes
(b) deficiency of nutrients
(c) environment
(d) defects in body organs
Answer: (b) deficiency of nutrients
Children who get enough calories but almost no protein develop this condition, which is common in areas where starch is the main food. It is specifically a "nutritional" disease.
Teacher's Tip: Protein is for "Proper growth" - without it, you get Kwashiorkor.
Exam Tip: Specify "protein deficiency" if the question asks for the exact nutrient.

2. Deficiency of vitamin C causes
(a) scurvy
(b) beri-beri
(c) rickets
(d) skin diseases
Answer: (a) scurvy
Scurvy makes your gums bleed and prevents wounds from healing correctly. Long ago, sailors used to get this because they had no fresh fruit on their long sea journeys.
Teacher's Tip: "C" is for "Citrus" - lemons and oranges prevent scurvy.
Exam Tip: "Bleeding gums" is the most famous symptom of Vitamin C deficiency.

3. Deficiency of vitamin K can cause
(a) haermorrhage
(b) bleeding gums
(c) rickets
(d) skin diseases
Answer: (a) haermorrhage
Vitamin K is responsible for helping your blood turn from liquid to a solid clot when you have a cut. Without it, you could lose too much blood from even a small scratch.
Teacher's Tip: "K" is for "Klotting" (Clotting).
Exam Tip: If you see "bleeding for a long time," immediately check for Vitamin K deficiency.

II. Fill in the blanks:
1. Protruding belly is a symptom noticed in kwashiorkor.
2. The disease kwashiorkor results from the deficiency of proteins.
3. The mineral fluorine is responsible for tooth decay.
Answer: (As highlighted in the blanks above)
These details focus on how specific missing items lead to visible symptoms. For example, a swollen belly in a thin child is a clear sign that they aren't getting enough protein from their diet.
Teacher's Tip: Fluorine is like "Armor" for your teeth.
Exam Tip: Most toothpastes have fluoride to prevent the decay mentioned in point 3.

III. Find the odd one out, giving reasons:

1. Kwashiorkor, scurvy, beri-beri, night blindness.
Answer: Kwashiorkor: Kwashiorkor is the odd-one out as it is a protein deficiency disease while the rest three are vitamin deficiency diseases.

2. Goitre, tooth decay, anaemia, rickets.
Answer: Rickets: Rickets is the odd-one out as it is a vitamin deficiency disease while the rest three are mineral deficiency diseases.
Classification by "type of nutrient" (protein, vitamin, or mineral) is a key skill in biology. It helps you understand exactly what the body is missing in each case.
Teacher's Tip: Vitamins are "A, B, C, D," while minerals are elements like "Iron, Iodine, Calcium".
Exam Tip: Always identify the "Group" to which the other three items belong in your reason.

IV. Name the following:
 

Question 1: Three vitamin-deficiency diseases.
Answer:
1. Night blindless (due to deficiency of Vitamin A).
2. Scurvy (due to deficiency of Vitamin C).
3. Rickets (due to deficiency of Vitamin D).
These three are the most well-known examples of how missing just a tiny amount of a vitamin can have a huge effect on your life. Eating a variety of fruits, veggies, and dairy protects you from all three.
Teacher's Tip: A, C, and D are the "Alphabet of Health".
Exam Tip: List the vitamin alongside the disease to get extra credit for thoroughness.

Question 2: Three mineral-deficiency diseases.
Answer:
1. Anaemia (due to deficiency of iron).
2. Goitre (due to deficiency of iodine).
3. Tooth decay (due to deficiency of fluorine).
Minerals come from the earth and enter our food through the soil. That is why eating whole grains and plants is so important for getting these essential elements.
Teacher's Tip: Iron = Blood; Iodine = Neck; Fluorine = Teeth.
Exam Tip: Remember that minerals are inorganic elements, whereas vitamins are organic compounds.

V. Mention the food constituents which may be lacking in one’s diet, in case of the following:
1. A child having rickets.
2. A person suffering from scurvy.
3. A person suffering from beri-beri.
4. A child suffering from kwashiorkor.
5. A person suffering from poor eyesight.
6. A person suffering from anaemia.
Answer:
1. Vitamin D and calcium.
2. Vitamin C.
3. Vitamin B.
4. Protein and energy giving carbohydrates.
5. Vitamin A.
6. Iron.
This list matches common health problems with the specific nutrient that can fix them. If you know these, you can basically use food as a preventative medicine!
Teacher's Tip: Think of this like matching a "Key" to its "Lock".
Exam Tip: For Rickets, always mention BOTH Vitamin D and Calcium as they work together.

VI. Match the items in Column A with those in Column B:
Answer:
1. Beri-beri - (d) Vitamin $B_{1}$
2. Anaemia - (e) Iron
3. Scurvy - (a) Vitamin C
4. Rickets - (b) Vitamin D
5. Goitre - (f) Iodine
6. Night blindness - (c) Vitamin A
Matching exercises like this are great for quick review before a test. They reinforce the direct link between a disease and its nutritional cause.
Teacher's Tip: Vitamin B is for Beri-beri (both start with B).
Exam Tip: Draw straight lines with a ruler or use letters (a, b, c) to stay neat and organized.

VII. Answer the following questions:
 

Question 1: What is meant by PEM? Name the diseases caused by PEM.
Answer: PEM (Protein energy malnutrition) is a term used to describe diets which lack proteins and energy giving carbohydrates. They are common among children. Kwashiorkor and marasmus are diseases which result from PEM.
This type of malnutrition is a major health issue in many developing countries. It means the body doesn't have enough building blocks (protein) or fuel (carbs) to grow and stay active.
Teacher's Tip: "PEM" = "Protein & Energy are Missing".
Exam Tip: Always expand the acronym "PEM" before listing the diseases to show complete understanding.

Question 2: Give the symptoms of kwashiorkor and marasmus.
Answer:
Symptoms of kwashiorkor:
1. Protruding belly.
2. Dark and scaly skin.
3. Brownish hair.
4. Stunted growth; underweight.
5. Swollen legs due to water accumulation.
6. Anaemia.
7. Mental retardation.
8. Reduced immunity.
9. Loss of appetite.
Symptoms of Marasmus:
1. Poor muscle development.
2. Bones showing through skin, no fat.
3. Weak legs.
4. Anaemia.
5. Grossly underweight.
6. Mental retardation.
7. Reduced immunity.
8. Loss of appetite.
While both diseases share symptoms like low immunity and mental slowdown, they look very different on the outside. Kwashiorkor's "swollen belly" is caused by fluid leaking into tissues, while Marasmus is a total "wasting away" of all fat and muscle.
Teacher's Tip: Kwashiorkor is "Swollen" and Marasmus is "Skinny".
Exam Tip: Be sure to differentiate clearly between the two when listing points; don't mix up the "protruding belly" symptom.

Question 3: Why should we not eat polished rice?
Answer: Polished rice is an example of ‘processed’ food. Processing removes many of the Vitamin B’s. Beri-beri is caused by the lack of Vitamin $B_{1}$. Therefore, we should not eat polished rice.
The outer brown layer of rice contains most of the natural nutrients and fiber. When rice is "polished" to look white and shiny, that healthy layer is rubbed away, leaving mostly just starch behind.
Teacher's Tip: Brown rice is "Whole" and White rice is "Hollow".
Exam Tip: Link "Polished Rice" directly to "Vitamin $B_{1}$" and "Beri-beri" for a perfect answer.

MICROORGANISMS AND DISEASES

I. Multiple choice questions. Tick (✓) the correct choice:

1. Which of the following diseases is spread through coughing and sneezing?
(a) Diphtheria
(b) Hepatitis
(c) Tetanus
(d) Polio
Answer: (a) Diphtheria
This is an airborne disease that attacks the nose and throat. When an infected person coughs, tiny droplets of germs fly into the air for others to breathe in.
Teacher's Tip: Anything that attacks the throat is usually spread through the air.
Exam Tip: Use the term "droplet infection" to describe how coughing and sneezing spread germs.

2. Which of the following diseases is transmitted by a carrier?
(a) Dengue
(b) Tetanus
(c) Hepatitis
(d) Common cold
Answer: (a) Dengue
Dengue cannot spread from person to person just by touching or talking. It needs a mosquito (the carrier) to pick up the virus from one person and "inject" it into another.
Teacher's Tip: Carriers are the "Delivery drivers" for diseases.
Exam Tip: Another word for carrier in biology is "Vector".

3.Which of the following diseases is spread through infected rats?
(a) Hepatitis
(b) Dengue
(c) Plague
(d) Common cold
Answer: (c) Plague
Plague is caused by bacteria that live on fleas, which in turn live on rats. Keeping cities clean of rodents is the best way to prevent this very dangerous history-making disease.
Teacher's Tip: Think of "Rats-Fleas-Plague" as a chain.
Exam Tip: "Yersinia pestis" is the name of the bacteria that causes Plague if you want to be extra precise.

4.Which of the following is a non-infectious disease?
(a) Cholera
(b) Thypoid
(c) Diabetes
(d) Plague
Answer: (c) Diabetes
You cannot "catch" diabetes from a friend. It is an internal problem with how the body handles sugar, often caused by genetics or a malfunctioning organ.
Teacher's Tip: Non-infectious = Non-sharing.
Exam Tip: Use "Diabetes" or "Heart Disease" as your go-to examples for non-infectious conditions.

5. A disease spread by the bite of a mad dog is
(a) Rabies
(b) Plague
(c) Polio
(d) Measles
Answer: (a) Rabies
The virus is contained in the dog's saliva and enters our body through the open wound of the bite. It is extremely important to get treated right away before symptoms start.
Teacher's Tip: A "mad dog" usually means a dog that already has Rabies.
Exam Tip: Link "saliva" and "animal bite" directly to Rabies in your answers.

II.Define the following:
1. Pathogen
2. Vector
3. Droplet infection
4. Infectious diseases
Answer:
1. Pathogen: The microbes that cause disease are called pathogens. Example : Bacteria, virus, etc.
2. Vector: A vector is an organism that carries disease causing microbes (pathogens) from one host to another. They are the carriers of infection. Example: Mosquito, housefly, etc.
3. Droplet infection: Droplet infection is an infection transmitted from one individual to another by droplets of saliva or nasal moisture during coughing, sneezing, speaking and spitting.
4. Infectious diseases: The diseases which spread from an infected person to a healthy person through air, water, food, soil or physical contact are called communicable diseases. Example : Common cold, chickenpox, etc.
These definitions categorize how germs move and make us sick. Understanding a "Vector" vs. a "Pathogen" is like knowing the difference between a "Truck" and the "Cargo" it carries.
Teacher's Tip: Pathogen = Germ; Vector = Bug carrier.
Exam Tip: Always provide an example when defining these terms to get full marks.

III. Mention the causal organisms of the following diseases:
1. Cholera
2. Tuberculosis
3. Common cold
4. Chickenpox
5. Typhoid
6. Polio
7. Rabies
Answer:
1. Cholera - Bacteria
2. Tuberculosis - Bacteria
3. Common cold - Virus
4. Chickenpox - Virus
5. Typhoid - Bacteria
6. Polio - Virus
7. Rabies - Virus
This list groups diseases by their biological "family." Knowing if a disease is bacterial or viral tells us which medicines (like antibiotics) will work and which won't.
Teacher's Tip: Most respiratory and "bite" diseases are viral; most stomach/gut diseases are bacterial.
Exam Tip: Memorize this list as it is a very common "Match the Following" question.

IV. Answer the following questions:
 

Question 1: What are communicable diseases? Name three such diseases.
Answer: Diseases which spread from an infected person to a healthy person are called communicable or infectious diseases. These diseases are caused through infections by microbes called pathogens. Example: Cholera, typhoid, cold, malaria, AIDS.
These diseases are "social" because they travel through human interactions. Simple actions like wearing a mask or washing hands can break the chain of communication for these germs.
Teacher's Tip: Communicable = Contagious.
Exam Tip: List "Common Cold" as it is the easiest and most recognizable example.

Question 2: List the different ways by which communicable dise ases are transmitted.
Answer: Communicable diseases are transmitted broadly by two modes:
1. Direct transmission: It is by
Direct contact: From skin to skin. Examples: eye infection (conjunctivitis), skin diseases, etc.
Droplet infection: From droplet of saliva or nose during cough, sneezing, speaking and spitting. Examples: Tuberculosis (TB), common cold, whooping cough, influenza.
Contact with soil: Example: mycosis, tetanus.
Inoculation into skin: Microbes may inoculate directly into skin. Examples: Rabies virus is inoculated by dog bite, hepatitis B virus is inoculated through contaminated needles and syringes.
2. Indirect transmission: It is by
Transmission of microbes through water and food (vehicle borne transmission): Examples: typhoid, cholera, polio, food poisoning, diarrhoea etc.
Transmission by blood: Examples: Hepatitis B and malaria
Transmission of microbes by an arthropod/living carrier (vector borne): Examples: malaria, dengue are transmitted by mosquito, typhoid, cholera are transmitted by housefly, plague is transmitted by rat flea, etc.
Transmission through fomites: Fomites include soiled clothes, towel, cups, spoon, toys, etc. Examples: diptheria, eye and skin infection.
Transmission through unclean hands: Examples: typhoid, intestinal parasites.
Air borne transmission: Examples: epidemic typhus.
This comprehensive list shows how creative germs can be when trying to find a new person to infect. From soil to air to houseflies, they use every possible path to survive.
Teacher's Tip: Direct = Touch/Droplets; Indirect = Water/Food/Bugs.
Exam Tip: Be sure to distinguish between "Vector-borne" (bugs) and "Vehicle-borne" (food/water).

Question 3: Differentiate between communicable and non-communicable diseases.
Answer:
Communicable diseases
1. Diseases which spread from one person to another.
2. These are also called as infectious diseases.
3. These diseases are caused by microbes called pathogens.
4. Examples: AIDS, cholera, cold, mumps, typhoid etc.
Non-communicable diseases
1. Diseases which do not spread from person to person and remain confined to the diseased person.
2. These are also called as non-infectious diseases.
3. These diseases are not caused by microbes.
4. Examples: allergy, diabetes, anaemia, etc.
The biggest difference is that communicable diseases are "caught" from the environment or people, while non-communicable ones are "developed" within your own body. One is about public hygiene, while the other is often about personal habits and genetics.
Teacher's Tip: Communicable = Sharing; Non-communicable = Solo.
Exam Tip: Always use a table format for "Differentiate" questions for better clarity and higher scores.

DISEASES DUE TO MALFUNCTIONING OF BODY ORGANS, FIRST AID MEASURES AND HYGIENE

I. Multiple choice questions. Tick (✓ ) the correct choice:

1. Malfunctioning of pancreas causes
(a) diabetes
(b) arthritis
(c) cataract
(d) goitre
Answer: (a) diabetes
The pancreas is responsible for making a hormone called insulin that regulates blood sugar. When it fails to produce enough, your blood sugar rises to dangerous levels.
Teacher's Tip: Think of the pancreas as the body's "Sugar Control Center".
Exam Tip: Link "Pancreas" and "Insulin" together in every answer about diabetes.

2. First vaccine was produced by
(a) Pasteur
(b) A. Fleming
(c) Jenner
(d) Robert Hooke
Answer: (c) Jenner
Edward Jenner created the first smallpox vaccine in 1796 using the cowpox virus. His work saved millions of lives and started the whole field of immunisation.
Teacher's Tip: "Jenner" starts the "Journey" of vaccines.
Exam Tip: Remember the date 1796 if you are writing a detailed history of medicine.

3. Cataract is a disease of the
(a) heart
(b) eye
(c) kidney
(d) pancreas
Answer: (b) eye
Specifically, the natural lens inside your eye becomes cloudy, like looking through a foggy window. It is one of the most common causes of vision loss in older adults.
Teacher's Tip: Eye = Vision; Cataract = Cloudy Vision.
Exam Tip: Don't confuse it with Glaucoma, which is also an eye disease but affects pressure, not clarity of the lens.

II.Fill in the blanks:

1. The disease caused by the bite of a mad dog is rabies.
2. Diseases of heart and kidney are due to malfunctioning of body organs.
3. Uremia is caused due to the malfunctioning of kidney.
Answer: (As highlighted in the blanks above)
These sentences connect a specific cause to a medical name or organ. For instance, when your kidneys can't filter out waste correctly, that toxic buildup is called Uremia.
Teacher's Tip: "Uremia" has "Ure-" for "Urea" (waste) and "-emia" for "Blood".
Exam Tip: Be sure to write "malfunctioning of body organs" in full for point 2.

III. Find the odd one out, giving reasons:

1.Diabetes, arthritis, cataract, obesity.
Answer: Obesity: Obesity is the odd one out as it is caused by imbalance in diet (over-nutrition) while the rest three are the diseases due to malfunctioning of body organs.
While obesity is about eating too much, the other three are about organs or systems simply not working as they should due to age or disease. One is a nutritional issue, while the others are "organ failure" issues.
Teacher's Tip: Obesity = Too much food; Others = Organ breakdown.
Exam Tip: Using the term "Degenerative" for arthritis and cataract is a great scientific way to group them.

IV. Define the following:
1. Vaccination
2. Immunisation
3. Immunity
4. Vaccine.
5. Pathogen
6. Atherosclerosis
Answer:
1. Vaccination: Vaccination is a method of making the body immune to a particular disease by injecting killed or weakened disease causing microbe into a body to stimulate the formation of antibodies and develop immunity to that disease causing microbe.
2. Immunisation: Immunisation is body’s natural defence mechanism which acts by producing antibodies against the antigens infecting the body.
3. Immunity: The ability of an organism to resist and overcome infection is called immunity.
4. Vaccine: A vaccine is a biological preparation of a weakened or killed pathogen (disease causing microbes) which stimulates the formation of antibodies and develops immunity against a particular disease.
5. Pathogen: Any organism that is capable of causing disease is called a pathogen. Examples : bacteria, virus or other microorganism.
6. Atherosclerosis: Atherosclerosis is a disease caused by the malfimtioning of heart wherein the arterial walls get hardened and thickened, reducing the flow of blood and raising the blood pressure.
These definitions form the basic vocabulary for understanding modern medicine. From how we protect ourselves (vaccines) to what we are fighting (pathogens), these terms cover the battle between humans and germs.
Teacher's Tip: Immunity is your body's "Shield," and a vaccine is the "Shield Training".
Exam Tip: Be very careful to distinguish between Vaccination (the act) and Immunisation (the result).

V. Answer the following questions:
 

Question 1: Write, in brief, about the following:
(a) Fever
(b) Allergy
(c) First-aid measures in case of cuts, burns, bites and stings.
Answer:
(a) Fever: Fever is the most common symptom of an infection in the human body. The body temperature rises above the normal i.e., $37^{\circ}C$ ($98.6^{\circ}F$). Fever might be associated with pain in the body, headache and tiredness. Rest, light diet, fluids and medicines help in reducing fever.
(b) Allergy: Allergy is an excessive sensitivity of the human body to some substances which are otherwise harmless. The allergens include dust, pollen grains, spores, furs, etc. Asthma and hay fever are examples of allergies. Rashes, itching, wheezing and sneezing are common symptoms of allergy.
(c) First-aid in case of cuts: Cut area should be cleaned and washed with warm water. Foreign matter, if any, should be removed. Wound area be raised above the heart level and bandage to be put after the blood flow stops.
1. First-aid in case of burns: Hold the burnt area under cold running water in first and second degree bums for 15 minutes. Wash with soap and leave uncovered. Give the tetanus injection. In case of third-degree bums, cover the burnt with dry, sterile dressing and contact the emergency medical services.
2. First-aid in case of bites: Hold the bite area under cool running water for 15 minutes. Wash with soap and water. Rinse again. Dry the area, elevate the bite area above the heart level for 8 hours and give a tetanus injection. In case of a snake bite, run water over the bite, mb powdered potassium permanganate and put a piece of cloth tightly around the area to prevent the poison from reaching heart and other body parts.
3. First-aid in case of stings: Remove the sting with tweezers. Wash the area with soap and cold water, apply oil or vaseline, cover with sterile gauze. If swelling, apply ice. Keep the stung area above the heart.
First-aid is the "immediate" help you give someone until professional doctors arrive. Knowing these steps can literally save a life during an emergency at home or school.
Teacher's Tip: For burns, use cold water, NEVER ice directly, and never butter!
Exam Tip: Always specify "cold running water" for both burns and bites in your answers.

Question 2: What would you do to lead a healthy life?
Answer: Personal hygiene is very important to lead a healthy life. It can be done by:
1. Proper diet: Balanced diet is very important.
2. Sleep: Adequate sleep of 6-8 hours a day.
3. Regular exercise: Sufficient physical activity.
4. Cleanliness: Keeping the body clean to prevent infections.
5. Proper lifestyle: Junk foods, long hours of table work, late night sleeps etc. should be avoided to lead a healthy life.
Health is a mix of what we eat, how much we move, and how well we rest. Making small, good choices every day builds up a strong body that can resist diseases naturally.
Teacher's Tip: Eat your colors (veggies) and move your muscles every day!
Exam Tip: List at least five points for "How to lead a healthy life" to get full marks.

Question 3: What steps would you take to prevent and control diseases?
Answer: Prevention and control of diseases can be done by:
1. Proper sanitation.
2. Provision of safe and clean water supply in adequate quantity.
3. Spray of insecticides to prevent mosquito breeding
4. Personal hygiene which includes proper diet, sleep, regular exercise, cleanliness and healthy lifestyle.
5. Immunisation (vaccination).
6. Health education.
Controlling diseases requires both personal action (like washing hands) and community action (like mosquito spraying). When everyone is educated about health, it becomes much harder for an epidemic to start.
Teacher's Tip: "Prevention is better than cure" - it's cheaper and easier too!
Exam Tip: Mention "Health education" as a point because knowing the rules is the first step to following them.

Question 4: Mention the contributions of 1. Edward Jenner and 2. Louis Pasteur.
Answer:
1. Edward Jenner was the first to develop the technique of vaccination in 1798.
2. Louis Pasteur established that many diseases were caused by microbes and he demonstrated the principle of immunisation, vaccines and antibodies.
These two men are the fathers of modern immunology. Because of their work, we no longer have to live in fear of once-deadly diseases like smallpox or rabies.
Teacher's Tip: Jenner discovered it, and Pasteur explained how it all worked.
Exam Tip: Mention the year "1798" for Jenner to show historical accuracy.

Question 5: What is diabetes? What are the symptoms?
Answer: Diabetes is a disease caused by the malfunctioning of pancreas in the body. When enough insulin is not produced by pancreas, the sugar levels rise in the blood and urine. Symptoms of diabetes include excessive thirst, frequent urination at night, loss of weight and fatigue.
Because the body can't process sugar correctly, it starts to get "thirsty" and tired all the time. Managing your diet and keeping active are the most important parts of living with this condition.
Teacher's Tip: Diabetes is a "Sweet Disease" but with bitter consequences for the body.
Exam Tip: Mention "excessive thirst" as the primary symptom teachers look for.

Question 6: What is atherosclerosis? Name the organs which are affected in this disease.
Answer: Atherosclerosis is a disease caused by the malfunctioning of circulatory system in the body. The arterial walls get hardened and thickened, reducing the flow of blood. This raises the blood pressure.
This disease primarily affects the heart and the major arteries throughout the body. It's like having old, rusty pipes in a house; the water (blood) just can't flow as fast as it should.
Teacher's Tip: Atherosclerosis is "Hardening of the Arteries".
Exam Tip: Be sure to link this disease to the "Circulatory System" and "High Blood Pressure".

Question 7: How does vaccination prevent diseases?
Answer: A vaccine contains a killed or weakened disease causing microbe that is responsible for infection. Because the germ is killed, it cannot make the person sick. When a person receives a vaccine, the body reacts by producing antibodies in defence. The antibodies remain in the blood for long and destroys the germs of a particular disease. In other words, vaccines expose people safely to germs so that they can fight with the same germs in future against its specific disease.
This process "teaches" your immune system what the bad guys look like before they actually attack. It's like a spy giving your army the blueprints of the enemy's weapons so you can build the right defense early.
Teacher's Tip: Vaccines are "Germ-school" for your white blood cells.
Exam Tip: Use the word "Antibodies" as it is the key mechanism in how vaccines work.

CHAPTER ASSIGNMENT

I. Which of the following statements are true (T) and which ones are false (F)? Mark T or F:
1. AIDS is caused by a bacterium. False. (AIDS is caused by a virus.)
2. Sneezing is an example of droplet infection. True.
3. Malaria is a vector-borne disease. True.
4. Atherosclerosis is a disease of the liver. False. (Atherosclerosis is a disease of the heart.)
5. Filariasis is caused by worms. . True.
Answer: (As marked above)
These statements test your basic knowledge of what causes common diseases and how they travel. Correcting the "False" ones helps reinforce the right facts in your memory.
Teacher's Tip: Remember: AIDS = Virus; Atherosclerosis = Heart.
Exam Tip: If you write the correct fact next to a "False" answer, you show the examiner you really know your stuff.

II. Give differences between the following: 1. First degree burn and second degree burn
Answer:
First degree burn
1. It effects the skins outermost layer.
2. It is less severe.
3. There are no blisters. Just redness and swelling.
4. This is also called a superficial bum.
5. They are dry.
6. They heal on their own in a week or so.
7. Example: Ordinary sunburn.
Second degree burn
1. It effects epidermis and dermis of the skin.
2. It is more severe and painful.
3. The skin becomes red and has blisters.
4. This is also called as partial thickness bum.
5. They are moist.
6. They might need medical attention and heal in 2-3 weeks.
7. Example: Blisters formed by hot oil accidentally.
The presence of "blisters" is the easiest way to tell a second-degree burn apart from a first-degree burn. Because it goes deeper into the skin layers, it is much more dangerous and takes much longer to heal.
Teacher's Tip: Blisters = 2nd Degree.
Exam Tip: Use the words "Superficial" and "Partial Thickness" to describe these burns scientifically.

III. Answer the following questions:
Question 1: Give the first aid measures in case of second degree bums.
Answer: First-aid in case of second degree bums:
1. Hold the burnt area under cold running water for 15 minutes.
2. Do not break the blisters.
3. Wash the area with mild soap and water.
4. Dry and put an antibiotic oinment.
5. If blisters have not broken open, leave the area uncovered.
6. If blisters have broken open, bandage is needed.
It is very important NOT to break the blisters because they act like a natural bandage protecting the raw skin underneath. Breaking them opens the door for germs and infections to enter your body.
Teacher's Tip: Blisters are nature's "Band-Aids" - leave them alone!
Exam Tip: Mention "Cold running water" as the very first step for any burn question.

Question 2: Name three commonly used vaccines.
Answer: Three commonly used vaccines are:
1. BCG for tuberculosis.
2. Salk vaccine for polio.
3. DPT for diptheria, pertussis (whooping cough) and tetanus.
Most children receive these vaccines before they even start school. They are the reason why we no longer see large outbreaks of these dangerous diseases in many countries.
Teacher's Tip: BCG = Lungs; DPT = Triple Threat (3 diseases).
Exam Tip: Be sure to write the full names of the diseases next to the vaccine acronyms.

Question 3: How vaccination helps to prevent diseases?
Answer: A vaccine contains a killed or weakened disease causing microbe that is responsible for infection. Because the germ is killed, it cannot make the person sick. When a person receives a vaccine, the body reacts by producing antibodies in defence. The antibodies remain in the blood for long and destroys the germs of a particular disease. In other words, vaccines expose people safely to germs so that they can fight with the same germs in future against its specific disease.
This "safe exposure" is the most clever trick in medicine. It turns your immune system into a library of germs, so it's always ready with the right answer to any attack.
Teacher's Tip: Vaccination = Training; Disease = The Real Fight.
Exam Tip: This is the same as the earlier question, but it's worth re-studying as it's a "favourite" exam topic.

Question 4: Why should you not allow water to stagnate near your house?
Answer: We should not allow water to stagnate near our house because:
1. Stagnant water is a breeding place for several mosquitoes which are carriers of many diseases like malaria and dengue.
2. It starts growing alga, etc. and stinks and rots the ground.
When water sits still, it becomes a perfect "nursery" for mosquito larvae and bacteria. By emptying out stagnant water, you are actively destroying the homes of the pests that carry diseases.
Teacher's Tip: Keep it moving or keep it dry!
Exam Tip: Use the term "breeding ground" when talking about stagnant water and insects.

IV. Crossword Puzzle DOWN

1. A disease caused due to the bite of a mad dog. (6)
2. Kwashiorkor and marasmus are caused due to the deficiency of this food component. (7)
3. A disease causing bleeding gums. (6)ACROSS
4. A disease due to deficiency of vitamin D. (7)
5. Diabetes is caused due to deficiency of this hormone.(7)
6. The deficiency of this mineral causes anaemia. (4)
Answer:
DOWN: 1. RABIES, 2. PROTEIN, 3. SCURVY.
ACROSS: 4. RICKETS, 5. INSULIN, 6. IRON.
Crosswords like this help you remember the technical names for medical concepts. Matching the number of letters to the word is a great way to double-check your spelling.
Teacher's Tip: Use the clue's letter count to help you find the right word.
Exam Tip: Learn these six words perfectly, as they are the "Most Important" terms for this chapter.

SOME MORE USEFUL QUESTIONS

Question 1: Obesity can lead to many problems. Name them.
Answer: Obesity can lead to heart disease, high blood pressure and diabetes.
Carrying extra weight makes the heart work much harder to pump blood through the body. It also changes how the body uses energy, which can lead to metabolic issues over time.
Teacher's Tip: Obesity is a "Gatekeeper Disease" - it opens the door for many others.
Exam Tip: List "Heart Disease" and "Diabetes" as your top two answers for this question.

Question 2: What does deficiency of carbohydrates lead to?
Answer: Deficiency of carbohydrates leads to:
1. Body weakness.
2. Loss of stamina.
Carbohydrates are the body's primary fuel source, like petrol for a car. Without enough, your body will start "burning" its own muscle and fat just to stay awake, which makes you feel exhausted.
Teacher's Tip: Carbs = Energy.
Exam Tip: Mention "Stamina" as a key term when discussing carbohydrate deficiency.

Question 3: hat are antibiotics?
Answer: Antibiotics are chemical substances that kill or stop the growth of microbes, thereby helping the body to fight diseases. Eg. penicillin.
It is important to know that antibiotics ONLY work against bacteria, not viruses. This is why a doctor won't give you antibiotics for a common cold, which is caused by a virus.
Teacher's Tip: Anti-Biotics = "Against Life" (Specifically bacteria life).
Exam Tip: Always include "Penicillin" as your example of an antibiotic.

Question 4: Who discovered the first antibiotic?
Answer: The first antibiotic, Penicillin, was discovered by Alexander Fleming.
He found it completely by accident when he saw that a certain type of mold was killing the bacteria in his lab dishes. This discovery changed the way we treat infections forever.
Teacher's Tip: Fleming found the "Wonder Drug" in moldy dishes!
Exam Tip: Remember both names: Alexander Fleming and Penicillin.

Question 5: Give examples of diseases caused by:
1. Fungus
2. Insect bite
3. Ingesting infected food and water
4. Pollution/allergy
5. Worms
Answer:
1. Food poisoning and ringworm.
2. Malaria and dengue.
3. Cholera and typhoid.
4. Asthma and hay fever.
5. Ascariasis and filariasis.
This categorization helps doctors know where a disease came from. If it came from a worm, you need different medicine than if it came from polluted air.
Teacher's Tip: Think about "How did it get inside me?" to find the category.
Exam Tip: Group these by "Source of Infection" in your notes for easy revision.

Question 6: Name two diseases caused by animal bites.
Answer: 1. Rabies by dog bite. 2. Snake poisoning by snake bite.
Animal bites are dangerous not just because of the wound, but because of the germs or poisons in the animal's saliva. Immediate cleaning and medical help are always required.
Teacher's Tip: Animal bite = Immediate Doctor visit!
Exam Tip: If the question asks for "microbial" diseases, only list Rabies, as snake poisoning is chemical.

Question 7: Name few contact infections.
Answer: Skin diseases, lice, chicken pox, conjunctivitis.
Contact infections spread through "Skin-to-Skin" touch or by sharing items like combs and towels. Keeping a safe distance from infected people and not sharing personal gear is the best prevention.
Teacher's Tip: Contact = Touch.
Exam Tip: "Conjunctivitis" is a classic example of a contact infection of the eyes.

Question 8: What bad habits can lead to bad health?
Answer: 1. Lack of personal hygiene. 2. Lack of exercise. 3. Addiction to fast food, drugs, tobacco, alcohol etc. 4. Poor sanitation.
Habits are the things we do every day that slowly add up to our overall health. Trading "couch time" for exercise and "chips" for apples are the best ways to reverse a bad trend.
Teacher's Tip: Good habits are the "Bank Account" of your health.
Exam Tip: "Sanitation" and "Hygiene" are two different but equally important points.

Question 9: Name few vectors and diseases caused by them.
Answer:
Mosquito: malaria, dengue, filaria.
Housefly: typhoid, cholera, polio.
Sandfly: kalaazar. –
Rat flea: plague.
Vectors act like a bridge between a sick person and a healthy person. By killing the vectors (using nets or sprays), we can stop the diseases even if the germs are still around.
Teacher's Tip: Vectors are the "Taxi Drivers" of the germ world.
Exam Tip: Match each insect correctly to its disease; don't mix up Mosquito and Housefly!

Question 10: Name the vitamin and mineral whose deficiency causes rickets.
Answer: Deficiency of calcium and vitamin D causes rickets.
Vitamin D is like the "helper" that allows your body to absorb calcium. Without enough of either one, your bones will stay soft and may even bend as you grow.
Teacher's Tip: Sunlight helps your body make its own Vitamin D for free!
Exam Tip: Always mention both (Calcium and Vit D) for a complete answer.

Question 11: Name the nutrient lacking in one7s diet it a person suffers from:
1. Haemorrhage
2. Dehydration
3. Paralysis
4. Tooth decay
5. Skin diseases
Answer: 1. Vitamin K, 2. Sodium, 3. Potassium, 4. Vitamin D and fluorine, 5. Vitamin $B_{2}$.
This list connects very specific nutrients to major body functions. For example, Potassium is vital for your nerves and muscles to "talk" to each other, which is why a lack of it can lead to paralysis.
Teacher's Tip: Most of these are "Micro-nutrients" - you only need a tiny bit, but it's very important.
Exam Tip: Associate "Dehydration" with "Sodium" loss specifically.

Question 12: Who gave the ‘germ theory of disease’?
Answer: Louis Pasteur.
Before Pasteur, people thought diseases came from "bad air" or "evil spirits." He proved that invisible microbes are the real cause, which allowed us to finally start fighting them correctly.
Teacher's Tip: Pasteur is the "Germ Proof" scientist.
Exam Tip: Associate "Pasteur" with "Pasteurization" and "Germ Theory".

Question 13: How can microorganisms enter our body?
Answer: 1. Through the air we inhale. 2. Through the water we drink. 3. Through the food we eat. 4. Through skin.
Germs are always trying to find a "door" into our body, which is warm and full of nutrients. Our skin is our main wall, but we have "open doors" in our nose and mouth that we must protect.
Teacher's Tip: Your body is a "Castle" and germs are trying to find an open gate.
Exam Tip: List all four entry points for a full-mark descriptive answer.

Question 14: What is conjunctivitis?
Answer: Conjunctivitis is a viral disease of the eye which is highly infections i.e., spreads from one person to another very fast.
It is often called "Pink Eye" because it makes the whites of the eyes look red and swollen. It's very important not to touch your eyes and to wash your hands constantly if you have it.
Teacher's Tip: Pink Eye is "Super Catchy" - don't share towels!
Exam Tip: Define it as a "viral infection of the conjunctiva" for a scientific edge.

Question 15: Name few diseases which are transmitted by air.
Answer: Common cold, chicket pox, tuberculosis, measles.
These diseases stay in the air as tiny mist droplets after someone coughs. This is why crowded rooms with no fresh air can be risky during flu season.
Teacher's Tip: Air-borne = Catching it just by breathing.
Exam Tip: List at least three examples to show you have a wide range of knowledge.

Question 16: What are degenerative diseases? Why do they occur?
Answer: Diseases due to malfunctioning of body organs are called degenerative diseases. Malfunctioning of body organs occurs due to ‘wear and tear’ and ageing of body.
Just like a car gets old and its parts start to break, our body organs can wear out after decades of use. Keeping a healthy lifestyle can slow down this "wear and tear" process significantly.
Teacher's Tip: Degenerative = "Downturn" in health due to age.
Exam Tip: Use the words "Ageing" and "Wear and tear" in your explanation.

Question 17: Name few diseases caused by malfunctioning of body organs.
Answer:
1. Malfunctioning of pancreas causes diabetes.
2. Malfunctioning of eyes causes cataract. .
3. Malfunctioning of bones cause arthritis.
4. Malfunctioning of kidneys cause uremia.
5. Malfunctioning of heart causes coronary heart disease and atherosclerosis.
This list matches organs directly to their specific failures. When an organ is "malfunctioning," it means it is still there, but it is not doing its job correctly for the rest of the body.
Teacher's Tip: Every organ has its own "Special Sick Name".
Exam Tip: Match Pancreas-Diabetes and Kidney-Uremia for quick exam points.

Question 18: Which body part produces insulin?
Answer: Islets of Langerhans present in pancreas produce the hormone insulin.
These "islets" are tiny clusters of cells that act like sensors for sugar in your blood. They release exactly the right amount of insulin to keep your energy levels steady.
Teacher's Tip: Islets of Langerhans are like "Islands" of sugar-control cells.
Exam Tip: Use the specific name "Islets of Langerhans" instead of just "Pancreas" for full marks.

Question 19: What are coronary heart diseases?
Answer: Coronaiy heart diseases are diseases due to malfunctioning of heart wherein the blood supply to the heart muscles reduces leading to reduced supply of oxygen to it. This can lead to a temporary pain in the chest. Hardening of arteries which supply blood to the heart muscles cause this disease.
Since the heart is a giant muscle that never stops, it needs a constant "refill" of oxygen. If the pipes (coronary arteries) get blocked, the heart muscle starts to "starve" for oxygen, which causes pain.
Teacher's Tip: Coronary = "Crown" - these arteries wrap around the heart like a crown.
Exam Tip: Link "reduced oxygen supply" to "chest pain" in your description.

Question 20: Name a disease which causes opaque eye lens and hence blindness.
Answer: Cataract.
"Opaque" means light cannot pass through it, just like a stone wall. If light can't get through the lens to the back of your eye, you cannot see anything.
Teacher's Tip: Opaque = No light through; Vision = Impossible.
Exam Tip: cataract is the #1 cause of blindness worldwide, so it's a common question.

Question 21: What is rabies?
Answer: Rabies is a viral disease caused by the bite of a rabid dog or monkey or rabbit. Saliva of the infected animal causes the rabies infection.
Rabies travels through the nerves to the brain, which is why it causes such strange and aggressive behavior. Vaccinating pets is the best way to keep this disease away from human homes.
Teacher's Tip: Rabid = Sick with Rabies.
Exam Tip: Mention "saliva" as the way the virus moves from the animal to the human.

Question 22: What are antibodies?
Answer: Antibodies are substances (proteins) which are produced by our body to attack the foreign bodies and they protect the host from disease.
Every antibody is shaped like a "Y" and is custom-made to stick to a specific germ. Once they stick, they act like a flag that tells your other white blood cells to come and eat the germ.
Teacher's Tip: Antibodies are the "Soldiers" in your blood.
Exam Tip: Define them specifically as "proteins" for a high-quality scientific answer.

23. Fill in the blanks:

1. Malfunctioning of kidneys can lead to accumulation of toxic substances in the body.
2. Lack of insulin may lead to diabetes.
3. A disease is opposite to health.
4. Intake of inadequate or excess food or unbalanced diet leads to malnutrition.
5. Diseases due to infection by microorganisms are called communicable diseases.
6. Louis Pasteur proved that microbes cause diseases
7. Inflammation of joints result in arthritis.
Answer: (As highlighted in the blanks above)
These basic concepts link biology to daily life and history. For example, knowing that Pasteur proved "germs cause disease" is the reason we now wash our hands and pasteurize our milk.
Teacher's Tip: Arthritis = Joint pain; Diabetes = Sugar problem.
Exam Tip: Be careful to use the plural form "diseases" or "kidneys" where needed to match the sentence.

Question 24: Give a brief note on body’s natural defence mechanism to overcome diseases.
Answer:
1. The skin acts as a barrier to the entry of microbes.
2. Tiny hair and mucous in the nose trap dust and microbes.
3. Digestive juices in the stomach kill microbes which enter the body.
4. White blood cells in the blood destroy the microbes.
5. Immune system produces antibodies against foreign particles.
Our body has "three lines of defense": physical walls (skin/hair), chemical traps (stomach acid), and an active army (WBCs). This multi-layered system is why we stay healthy most of the time even though germs are everywhere.
Teacher's Tip: Your body is a "Fortress" with many layers of protection.
Exam Tip: Listing "Skin," "Stomach Acid," and "WBCs" covers all the major defense systems.

Question 25: List few precautions taken to maintain personal hygiene and cleanliness.
Answer:
1. Wash your hands before and after meals.
2. Brush your teeth twice a day.
3. Don’t keep long nails.
4. Walking barefoot must be avoided.
5. Waste food material and garbage should be thrown in bins and covered properly.
Personal hygiene is about being "germ-smart" in your daily routine. By washing hands and covering waste, you are actively cutting off the paths that germs use to reach you.
Teacher's Tip: Hygiene is "Health Habits".
Exam Tip: Mentioning "long nails" or "walking barefoot" shows you understand how parasites (like worms) enter the body.