Detailed Notes: Chapter 1 – FOOD

1. Introduction to Food

Food is the fundamental substance consumed to provide nutritional support for an organism. It is essential for:

  • Energy Production: Fuels all bodily functions, from cellular processes to physical activities. The energy is measured in Kilocalories (kcal).

  • Growth and Repair: Supplies the building blocks (like proteins and minerals) for the formation of new tissues and the repair of damaged ones.

  • Maintenance and Regulation: Provides substances that regulate body temperature, control metabolic reactions, and maintain homeostasis (e.g., water, minerals, vitamins).

  • Protection: Strengthens the immune system to fight infections and diseases.

Sources of Food:

  • Plant Sources: Directly or indirectly, most food comes from plants.

    • Cereals: Wheat, rice, maize (carbohydrates).

    • Pulses: Lentils (dals), chickpeas (proteins).

    • Fruits and Vegetables: Vitamins, minerals, roughage.

    • Spices, Oils, Nuts, Sugar.

  • Animal Sources:

    • Milk and Dairy Products: Complete food, rich in proteins, fats, calcium.

    • Eggs, Meat, Fish: Rich source of high-quality protein and fats.

    • Honey.

2. Components of Food (Nutrients)

Nutrients are classified based on the quantity required by the body:

  • Macronutrients: Needed in large amounts.

    • Carbohydrates, Proteins, Fats, Water, Roughage.

  • Micronutrients: Needed in very small (trace) amounts but are crucial for proper functioning.

    • Vitamins and Minerals.

A. Carbohydrates

  • Chemical Composition: Primarily composed of Carbon (C), Hydrogen (H), and Oxygen (O) in a ratio where H and O are usually 2:1, as in water (H₂O), hence “hydrates of carbon.”

  • Primary Function: To serve as the primary and most readily available source of energy for the body, especially for the brain and nervous system.

  • Energy Yield: 1 gram of carbohydrate provides approximately 4 kcal (16.8 kJ) of energy.

  • Detailed Classification & Examples:

    1. Simple Carbohydrates (Sugars):

      • Monosaccharides: Single sugar units. Glucose (blood sugar), Fructose (fruit sugar), Galactose (part of milk sugar).

      • Disaccharides: Two monosaccharides linked. Sucrose (glucose + fructose; table sugar), Lactose (glucose + galactose; milk sugar), Maltose (glucose + glucose; malt sugar).

    2. Complex Carbohydrates (Polysaccharides):

      • Starch: Storage form of energy in plants. Digestible by humans.

      • Glycogen: Storage form of glucose in animals (in the liver and muscles). Often called “animal starch.”

      • Cellulose: A structural component of plant cell walls. It is dietary fibre or roughage, which humans cannot digest but is essential for gut health.

  • Metabolism and Storage:

    • Glycogenesis: The process of converting excess glucose into glycogen for storage in the liver and muscles.

    • Lipogenesis: When glycogen stores are full, the body converts excess carbohydrates into fats (triglycerides) for long-term storage in adipose tissue.

  • Dietary Sources: Cereals (wheat, rice, corn), root vegetables (potatoes, sweet potatoes), sugarcane, jaggery, fruits (bananas, mangoes).

  • Key Fact for CTET: Gluten is a protein found in wheat, barley, and rye. Some people have Celiac disease or gluten sensitivity, where gluten triggers an immune response damaging the small intestine.

  • Daily Requirement: Varies with activity level. An average adult requires about 500g, but growing children, athletes, and pregnant/lactating women need more.

  • Test for Starch (Iodine Test):

    • Procedure: Place a small amount of the food sample on a plate. Add 2-3 drops of iodine solution (yellowish-brown).

    • Positive Result: The appearance of a blue-black colour confirms the presence of starch.

    • Pedagogical Insight: This is a classic classroom experiment. A teacher must ensure students understand that the colour change is a chemical reaction between iodine and the starch molecule.

B. Proteins

  • Chemical Composition: Composed of Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N). Many also contain Sulphur (S), and some contain Phosphorus (P) or Iron (Fe).

  • Primary Function: Bodybuilding and Repair. They are the fundamental structural components of all living tissues—muscles, skin, hair, nails, etc. They also form functional molecules.

  • Functional Roles of Proteins:

    • Enzymes: Catalyse biochemical reactions (e.g., Amylase, Lipase).

    • Hormones: Regulate body processes (e.g., Insulin).

    • Transport: Haemoglobin transports oxygen.

    • Protection: Antibodies (Immunoglobulins) fight pathogens.

    • Structural: Collagen in skin, Actin and Myosin in muscles.

  • Structure: Proteins are polymers made of long chains of Amino Acids.

    • Essential Amino Acids (9): Cannot be synthesized by the human body and must be obtained from the diet. Examples: Lysine, Tryptophan, Valine, Methionine.

    • Non-Essential Amino Acids (11): Can be synthesized by the body. Examples: Alanine, Glutamine, Serine.

  • Biological Value of Protein Sources:

    • Complete Proteins (High Biological Value): Contain all essential amino acids in the right proportion. Sources: Animal proteins like milk, eggs, meat, fish.

    • Incomplete Proteins (Low Biological Value): Lack one or more essential amino acids. Sources: Plant proteins like pulses, nuts, grains. (Combining different plant sources, e.g., rice and dal, can provide all essential amino acids).

  • Energy Yield: 1 gram provides 4 kcal of energy (used only if carbohydrate and fat intake is insufficient).

  • Daily Requirement: About 50-60g for a sedentary adult. Requirement is higher for children, pregnant women, and athletes.

  • Deficiency Diseases:

    • Kwashiorkor: Primarily due to protein deficiency in the presence of adequate calories. Common in weakened children.

      • Symptoms: Stunted growth, oedema (swelling) in legs and abdomen, pot belly, thinning hair, skin dermatitis.

    • Marasmus: Due to a severe deficiency of both proteins and total calories.

      • Symptoms: Severe wasting of muscle and fat, “skin and bones” appearance, extreme weakness, growth retardation.

  • Test for Protein (Biuret Test):

    • Procedure: Make a paste or solution of the food item. Add 2 ml of 10% sodium hydroxide (NaOH) solution. Then, add 2-3 drops of 1% copper sulphate (CuSO4) solution. Shake well.

    • Positive Result: The appearance of a violet or purple colour indicates the presence of proteins.

C. Fats (Lipids)

  • Chemical Composition: Esters of fatty acids and glycerol (a triple alcohol). Composed of C, H, and O, but with a much lower proportion of O than carbohydrates.

  • Primary Function:

    1. Concentrated Energy Source: The most energy-dense nutrient.

    2. Insulation and Protection: Stored fat insulates the body against cold and protects vital organs as a cushion.

    3. Carrier of Vitamins: Essential for the absorption of fat-soluble vitamins (A, D, E, K).

  • Energy Yield: 1 gram of fat provides 9 kcal of energy (more than double that of carbs or proteins).

  • Classification of Fatty Acids:

    • Saturated Fats:

      • Structure: No double bonds between carbon atoms; “saturated” with hydrogen.

      • State: Usually solid at room temperature.

      • Sources: Animal fats (butter, ghee, lard), coconut oil, palm oil.

      • Health Impact: Excess consumption can raise LDL (“bad”) cholesterol, leading to atherosclerosis and increased risk of heart disease.

    • Unsaturated Fats:

      • Structure: Have one or more double bonds in their carbon chain.

      • State: Usually liquid (oils) at room temperature.

      • Sources: Plant and fish oils (groundnut oil, sunflower oil, olive oil, fish oil).

      • Health Impact: Generally heart-healthy. They help reduce LDL cholesterol.

      • Essential Fatty Acids: Linoleic acid (Omega-6) and Alpha-linolenic acid (Omega-3) cannot be synthesized by the body and must be included in the diet.

  • Storage: Stored in specialized cells called adipocytes that make up adipose tissue.

  • Health Issues: Obesity is a result of excessive fat storage. It is a risk factor for hypertension, diabetes, and cardiovascular diseases.

  • Daily Requirement: About 70g for an adult, with a focus on including more unsaturated fats.

  • Test for Fats (Paper Spot Test):

    • Procedure: Take a small piece of food and crush it. Wrap it in a piece of plain paper (like filter paper) and press firmly.

    • Positive Result: The appearance of a greasy, translucent spot on the paper that does not disappear upon drying indicates the presence of fats.

D. Vitamins

  • Concept: The term “Vitamine” (vital amine) was coined by Casimir Funk in 1912. They are complex organic compounds required in minute quantities for normal growth, metabolism, and overall health. They do not provide energy but are essential for energy-yielding processes.

  • Classification Based on Solubility:

    • Fat-Soluble Vitamins (A, D, E, K): Absorbed along with fats in the diet. Can be stored in the liver and adipose tissues. Risk of toxicity with overconsumption.

    • Water-Soluble Vitamins (B-complex and C): Not stored in the body to a significant extent (except B12). Excess is excreted in urine, so they must be consumed regularly.

Vitamin & Chemical Name
Solubility
Major Functions
Deficiency Diseases & Symptoms
Rich Food Sources
A (Retinol)
Fat
Vision (Rhodopsin synthesis), immune function, skin health.
Night Blindness (Nyctalopia), Xerophthalmia (dry eyes), dry skin.
Liver, eggs, milk, carrots, leafy greens (as Beta-carotene).
B₁ (Thiamine)
Water
Coenzyme in carbohydrate metabolism, nerve function.
Beri-Beri (nerve degeneration, muscle weakness, heart failure).
Whole grains, yeast, legumes, pork.
B₂ (Riboflavin)
Water
Coenzyme in energy production, skin and mucous membrane health.
Cheilosis (cracks at corners of mouth), glossitis (sore tongue), skin disorders.
Milk, eggs, liver, green leafy vegetables.
B₃ (Niacin)
Water
Coenzyme in redox reactions, DNA repair.
Pellagra (4 D’s: Dermatitis, Diarrhoea, Dementia, Death).
Meat, fish, eggs, peanuts, whole grains.
B₉ (Folic Acid)
Water
DNA synthesis, cell division, RBC formation.
Megaloblastic Anaemia (large, immature RBCs), neural tube defects in fetus.
Green leafy vegetables, liver, citrus fruits.
B₁₂ (Cyanocobalamin)
Water
DNA synthesis, RBC maturation, nerve cell health.
Pernicious Anaemia, nerve damage, fatigue.
Only animal sources: Liver, meat, eggs, milk.
C (Ascorbic Acid)
Water
Antioxidant, collagen synthesis (wound healing), boosts iron absorption, immune function.
Scurvy (bleeding gums, loose teeth, joint pain, poor wound healing).
Citrus fruits (amla, orange, lemon), guava, tomatoes.
D (Calciferol)
Fat
“Sunshine Vitamin” – regulates Calcium & Phosphorus absorption for bone mineralization.
Rickets in children (soft, weak, deformed bones). Osteomalacia in adults (bone pain, weakness).
Sunlight exposure, fatty fish, egg yolk, fortified milk.
E (Tocopherol)
Fat
Powerful antioxidant, protects cell membranes.
Rare; can cause nerve damage, muscle weakness.
Vegetable oils, nuts, seeds, leafy greens.
K (Phylloquinone)
Fat
Synthesis of blood clotting factors (Prothrombin).
Haemorrhagic Disease (excessive bleeding, delayed blood clotting).
Green leafy vegetables, broccoli, soyabean oil.
E. Minerals

Inorganic elements essential for various structural and regulatory functions.

Mineral
Major Functions
Deficiency Diseases & Symptoms
Rich Food Sources
Calcium (Ca)
Bone & teeth formation, blood clotting, nerve transmission, muscle contraction.
Rickets (children), Osteoporosis (adults – porous bones), muscle cramps.
Milk & dairy, leafy greens, ragi, small fish (eaten with bones).
Phosphorus (P)
Bone & teeth, component of ATP (energy currency), DNA, RNA, phospholipids (cell membranes).
Bone pain, weakness, loss of appetite. Often linked with Calcium & Vitamin D deficiency.
Milk, eggs, meat, nuts, whole grains.
Iron (Fe)
Core component of Haemoglobin (carries O₂), myoglobin (stores O₂ in muscles).
Iron-deficiency Anaemia (fatigue, weakness, pale skin, shortness of breath). Requirement is higher in adolescent girls and women due to menstrual blood loss.
Leafy greens (spinach), jaggery, liver, legumes, dry fruits.
Iodine (I)
Essential for synthesis of Thyroxine hormone by the thyroid gland.
Goitre (enlarged thyroid gland in the neck), Cretinism (severe mental & physical retardation in children if mother is deficient).
Iodised salt, seafood, seaweed.
Sodium (Na) & Potassium (K)
Electrolytes: Maintain fluid balance (Na extracellular, K intracellular), nerve impulse conduction, muscle contraction.
Na: Muscle cramps. K: Muscular weakness, irregular heartbeat.
Common salt (Na), bananas, oranges, potatoes (K).
Magnesium (Mg)
Bone component, cofactor for many enzymes, nerve and muscle function.
Muscle twitches, cramps, fatigue, mental disorders.
Nuts, seeds, whole grains, green leafy vegetables.
Fluorine (F)
Strengthens tooth enamel, prevents dental caries (decay).
Dental caries. Excess causes Fluorosis (mottling of teeth, bone deformity).
Fluoridated water, tea, fish.
Cobalt (Co)
A component of Vitamin B₁₂.
Manifests as Vitamin B₁₂ deficiency (Pernicious Anaemia).
Animal-based foods (meat, liver, milk).
F. Roughage (Dietary Fibre)

  • Composition: Mainly Cellulose, a complex carbohydrate that human digestive enzymes cannot break down.

  • Function:

    1. Adds Bulk: Gives bulk to the faeces, promoting regular bowel movements and preventing constipation.

    2. Prevents Diseases: Helps prevent digestive disorders like diverticulitis and may reduce the risk of colon cancer.

    3. Binds Cholesterol: Can help in lowering blood cholesterol levels.

  • Sources: Whole grains (whole wheat, oats), fruits (especially with skin), vegetables, pulses, nuts, and seeds.

G. Water

  • The Essence of Life: Makes up 60-70% of the human body weight.

  • Critical Functions:

    1. Universal Solvent: Medium for all biochemical reactions (digestion, absorption, excretion).

    2. Transport: Transports nutrients, hormones, and oxygen to cells and removes waste products.

    3. Temperature Regulation: Regulates body temperature through sweating and evaporation.

    4. Lubrication: Lubricates joints and acts as a shock absorber.

3. Balanced Diet

A balanced diet is one that contains all the essential nutrients in the correct proportions and quantities required for optimal growth, health, and functioning of the body.

  • Components: It must include:

    • Energy-giving foods: Carbohydrates and Fats.

    • Body-building foods: Proteins.

    • Protective and Regulatory foods: Vitamins, Minerals, Roughage, and Water.

  • Factors Influencing a Balanced Diet:

    • Age: Children and adolescents need more protein and calcium for growth.

    • Sex: Men generally require more calories than women. Women of reproductive age need more iron.

    • Physical Activity: A labourer requires more energy-giving foods than a person with a sedentary job.

    • Physiological State: Pregnant and lactating women have higher nutritional requirements.

  • Example: Milk is often called a “complete food” for infants because it contains a balance of proteins, fats, carbohydrates, vitamins (A, D, B₂, B₁₂), and minerals (Calcium, Phosphorus).

4. Food Preservation and Hygiene

A. Maintenance of Food Quality:

  • This involves preventing food from being contaminated (by microbes, chemicals, pests) or spoiled (by enzymatic degradation or microbial growth).

  • Food Hygiene is crucial to avoid food poisoning (like salmonellosis, botulism). It ensures that all stages—production, handling, storage, distribution, cooking, and serving—are carried out in a clean and safe manner.

B. Food Cleanliness:

  • Refers to the practice of ensuring that the food we eat is free from harmful contaminants.

  • Risks of Unhygienic Food:

    • Eating food exposed to dust and flies.

    • Consuming uncovered food and drinks.

    • Using contaminated water for drinking and cooking.

  • These practices can spread diseases like diarrhoea, typhoid, cholera, and hepatitis A.

C. Food Preservation Methods:
Food preservation involves treating and handling food to stop or slow down spoilage, loss of quality, edibility, or nutritional value.

  • Chemical Methods:

    • Using food preservatives like Sodium Benzoate, Potassium Benzoate (in jams, squashes), Salt, Sugar, Vinegar, Oil.

    • Principle: Creates an environment where microbes cannot grow. High salt/sugar concentration causes plasmolysis (water loss) in microbial cells, killing them.

  • Physical Methods:

    1. Storage Methods:

      • Dry Storage: For non-perishable items like sugar, flour, cereals, pulses.

      • Cold Storage (Refrigeration/Freezing): For perishable items like fruits, vegetables, milk, meat. On a commercial scale, large cold storages are used.

    2. Pasteurization: A process where milk is heated to about 70°C for 15-30 seconds and then rapidly cooled. This kills harmful pathogens without significantly altering the taste or nutritional value.

    3. Dehydration/Drying: Removal of water from food (e.g., fruits, vegetables). Microbes cannot grow without water.

    4. Canning and Bottling: Food is processed and sealed in an airtight container to prevent spoilage.

  • General Hygiene Practices:

    • Utensils and crockery should be cleaned thoroughly with a good quality detergent.

    • Use clean, potable water for drinking, cooking, and washing.

    • Avoid practices that destroy nutrients, e.g., overcooking vegetables leaches out water-soluble vitamins (B-complex and C).

CTET 2025: Complete Practice Set – FOOD

1. Basic Concept Based MCQs or Basic MCQs (Q1-Q10)

Q1. Which nutrient is primarily responsible for building and repairing body tissues?
(a) Carbohydrates
(b) Proteins
(c) Fats
(d) Vitamins
Answer: (b) Proteins
Explanation: Proteins are the fundamental building blocks of the body, essential for growth, repair, and maintenance of all tissues, including muscles, organs, and skin.

Q2. Which vitamin deficiency causes night blindness?
(a) Vitamin A
(b) Vitamin B
(c) Vitamin C
(d) Vitamin D
Answer: (a) Vitamin A
Explanation: Vitamin A is crucial for the synthesis of rhodopsin, the visual pigment in rod cells of the retina, which enables vision in dim light. Its deficiency leads to night blindness.

Q3. What is the main energy reserve in the human body?
(a) Glycogen
(b) Starch
(c) Cellulose
(d) Glucose
Answer: (a) Glycogen
Explanation: Glycogen is the storage form of glucose in animals and humans, primarily stored in the liver and muscles, serving as a readily mobilizable energy reserve.

Q4. Which mineral is essential for proper thyroid function?
(a) Iron
(b) Calcium
(c) Iodine
(d) Sodium
Answer: (c) Iodine
Explanation: Iodine is an essential component of thyroid hormones (thyroxine and triiodothyronine), which regulate metabolism, growth, and development.

Q5. What is the primary role of dietary fibre?
(a) Provide energy
(b) Aid digestion
(c) Build muscles
(d) Fight infections
Answer: (b) Aid digestion
Explanation: Dietary fibre adds bulk to stool, promotes regular bowel movements, prevents constipation, and supports overall digestive health.

Q6. Which vitamin is synthesized by the human body when exposed to sunlight?
(a) Vitamin A
(b) Vitamin B12
(c) Vitamin C
(d) Vitamin D
Answer: (d) Vitamin D
Explanation: Vitamin D can be synthesized in the skin when exposed to ultraviolet B (UVB) radiation from sunlight, making it unique among vitamins.

Q7. What is the energy yield per gram of carbohydrates?
(a) 2 kcal
(b) 4 kcal
(c) 7 kcal
(d) 9 kcal
Answer: (b) 4 kcal
Explanation: Carbohydrates provide approximately 4 kilocalories of energy per gram when metabolized in the body.

Q8. Which disease is caused by protein deficiency in children?
(a) Scurvy
(b) Rickets
(c) Kwashiorkor
(d) Beri-beri
Answer: (c) Kwashiorkor
Explanation: Kwashiorkor is a severe form of malnutrition caused by inadequate protein intake, characterized by edema, skin lesions, and growth impairment.

Q9. What is the main function of Vitamin K?
(a) Vision
(b) Blood clotting
(c) Bone health
(d) Immunity
Answer: (b) Blood clotting
Explanation: Vitamin K is essential for the synthesis of several proteins required for normal blood coagulation.

Q10. Which mineral is crucial for bone and teeth formation?
(a) Iron
(b) Iodine
(c) Calcium
(d) Sodium
Answer: (c) Calcium
Explanation: Calcium is the primary mineral component of bones and teeth, providing structural strength and rigidity.

2. Advanced Theory/Concept MCQs (Q11-Q30)

Q11. A teacher demonstrates that when iodine solution is added to a potato slice, it turns blue-black. This confirms the presence of:
(a) Proteins
(b) Fats
(c) Starch
(d) Vitamins
Answer: (c) Starch
Explanation: The blue-black colour formation with iodine solution is a characteristic chemical test specifically for starch, due to the formation of a starch-iodine complex.

Q12. Which of the following vitamins acts as an antioxidant and helps in iron absorption?
(a) Vitamin A
(b) Vitamin B12
(c) Vitamin C
(d) Vitamin D
Answer: (c) Vitamin C
Explanation: Vitamin C functions as a powerful antioxidant and enhances the absorption of non-heme iron from plant-based foods in the intestine.

Q13. The process of converting excess carbohydrates into fats for storage is called:
(a) Glycolysis
(b) Glycogenesis
(c) Lipogenesis
(d) Gluconeogenesis
Answer: (c) Lipogenesis
Explanation: Lipogenesis is the metabolic process through which acetyl-CoA is converted to triglyceride for storage when carbohydrate intake exceeds immediate energy needs.

Q14. Which pair of diseases results from deficiencies in B-complex vitamins?
(a) Scurvy and Rickets
(b) Beri-beri and Pellagra
(c) Goiter and Anemia
(d) Night blindness and Osteomalacia
Answer: (b) Beri-beri and Pellagra
Explanation: Beri-beri is caused by thiamine (B1) deficiency, while pellagra results from niacin (B3) deficiency, both belonging to the B-complex vitamin group.

Q15. A child presents with delayed wound healing and bleeding gums. The teacher should suspect deficiency of:
(a) Vitamin A
(b) Vitamin B1
(c) Vitamin C
(d) Vitamin D
Answer: (c) Vitamin C
Explanation: These are classic symptoms of scurvy, caused by vitamin C deficiency, which is essential for collagen synthesis and connective tissue maintenance.

Q16. Which mineral deficiency is most likely in a vegetarian athlete experiencing fatigue and decreased performance?
(a) Calcium
(b) Iron
(c) Sodium
(d) Iodine
Answer: (b) Iron
Explanation: Vegetarians are at higher risk for iron deficiency as plant-based iron (non-heme) has lower bioavailability than animal-based iron (heme), and athletes have increased iron requirements.

Q17. The Biuret test for proteins involves the use of:
(a) Iodine solution
(b) Copper sulfate and sodium hydroxide
(c) Benedict’s solution
(d) Sudan III stain
Answer: (b) Copper sulfate and sodium hydroxide
Explanation: The Biuret test uses copper sulfate in alkaline medium (sodium hydroxide) to detect peptide bonds, producing a violet colour with proteins.

Q18. Which water-soluble vitamin can be stored in the liver for several years?
(a) Vitamin B1
(b) Vitamin B6
(c) Vitamin B12
(d) Vitamin C
Answer: (c) Vitamin B12
Explanation: Unlike other water-soluble vitamins, vitamin B12 can be stored in the liver in significant amounts, providing a reserve that can last for 3-5 years.

Q19. A food item shows a translucent spot on paper. This indicates the presence of:
(a) Starch
(b) Protein
(c) Fat
(d) Vitamin
Answer: (c) Fat
Explanation: The paper spot test is used to detect lipids, which produce a translucent/greasy spot due to their non-polar nature and ability to make paper translucent.

Q20. Which vitamin deficiency causes megaloblastic anemia?
(a) Vitamin B6
(b) Vitamin B9
(c) Vitamin B12
(d) Both B9 and B12
Answer: (d) Both B9 and B12
Explanation: Both folate (B9) and cobalamin (B12) deficiencies can cause megaloblastic anemia, characterized by large, immature red blood cells.

Q21. The main function of sodium in the body is:
(a) Oxygen transport
(b) Nerve impulse transmission
(c) Bone formation
(d) Blood clotting
Answer: (b) Nerve impulse transmission
Explanation: Sodium ions play a crucial role in generating and transmitting nerve impulses by maintaining the membrane potential and facilitating depolarization.

Q22. Which food preservation method works by creating a hypertonic environment?
(a) Refrigeration
(b) Pasteurization
(c) Adding salt or sugar
(d) Canning
Answer: (c) Adding salt or sugar
Explanation: High concentrations of salt or sugar create a hypertonic environment that causes plasmolysis of microbial cells, inhibiting their growth.

Q23. A child from a low-income family shows stunted growth, edema, and skin lesions. The teacher should suspect:
(a) Marasmus
(b) Kwashiorkor
(c) Rickets
(d) Scurvy
Answer: (b) Kwashiorkor
Explanation: These are characteristic symptoms of kwashiorkor, resulting from severe protein deficiency despite possibly adequate calorie intake.

Q24. Which mineral is a component of hemoglobin?
(a) Calcium
(b) Iron
(c) Iodine
(d) Magnesium
Answer: (b) Iron
Explanation: Iron is an essential component of the heme group in hemoglobin, enabling oxygen transport in red blood cells.

Q25. The process of milk preservation that involves heating to 72°C for 15 seconds is called:
(a) Sterilization
(b) Pasteurization
(c) Homogenization
(d) Fermentation
Answer: (b) Pasteurization
Explanation: Pasteurization involves heating milk to specific temperatures (like 72°C for 15 seconds) to destroy pathogens while preserving nutritional quality.

Q26. Which vitamin deficiency causes poor bone mineralization in children?
(a) Vitamin A
(b) Vitamin C
(c) Vitamin D
(d) Vitamin K
Answer: (c) Vitamin D
Explanation: Vitamin D regulates calcium and phosphorus absorption, and its deficiency impairs bone mineralization, causing rickets in children.

Q27. The term “essential amino acids” refers to:
(a) All amino acids needed by the body
(b) Amino acids that can be synthesized by the body
(c) Amino acids that must be obtained from diet
(d) Amino acids found only in animal proteins
Answer: (c) Amino acids that must be obtained from diet
Explanation: Essential amino acids cannot be synthesized by the human body and must be obtained through dietary sources.

Q28. Which of the following is a function of potassium in the body?
(a) Maintaining fluid balance
(b) Forming hemoglobin
(c) Strengthening bones
(d) Blood clotting
Answer: (a) Maintaining fluid balance
Explanation: Potassium is the major intracellular cation that works with sodium to maintain proper fluid balance and osmotic pressure.

Q29. A food item turns violet when tested with copper sulfate and sodium hydroxide. This indicates presence of:
(a) Starch
(b) Protein
(c) Fat
(d) Vitamin C
Answer: (b) Protein
Explanation: This is the positive result of the Biuret test, specifically indicating the presence of peptide bonds in proteins.

Q30. Which vitamin is crucial for normal blood clotting?
(a) Vitamin A
(b) Vitamin D
(c) Vitamin E
(d) Vitamin K
Answer: (d) Vitamin K
Explanation: Vitamin K is essential for the synthesis of several clotting factors in the liver, including prothrombin.

3. Advanced Match the Following (Q31-Q40)

Q31. Match the following vitamins with their deficiency diseases:

Column A (Vitamin)
Column B (Deficiency Disease)
1. Vitamin A
A. Scurvy
2. Vitamin B1
B. Night blindness
3. Vitamin C
C. Beri-beri
4. Vitamin D
D. Rickets

(a) 1-B, 2-C, 3-A, 4-D
(b) 1-C, 2-B, 3-D, 4-A
(c) 1-A, 2-D, 3-C, 4-B
(d) 1-D, 2-A, 3-B, 4-C
Answer: (a) 1-B, 2-C, 3-A, 4-D
Explanation: Vitamin A deficiency causes night blindness; Vitamin B1 deficiency causes beri-beri; Vitamin C deficiency causes scurvy; Vitamin D deficiency causes rickets.

Q32. Match the following minerals with their primary functions:

Column A (Mineral)
Column B (Function)
1. Calcium
A. Oxygen transport
2. Iron
B. Bone formation
3. Iodine
C. Thyroid function
4. Sodium
D. Nerve conduction

(a) 1-B, 2-A, 3-C, 4-D
(b) 1-C, 2-B, 3-D, 4-A
(c) 1-A, 2-D, 3-B, 4-C
(d) 1-D, 2-C, 3-A, 4-B
Answer: (a) 1-B, 2-A, 3-C, 4-D
Explanation: Calcium is crucial for bone formation; Iron enables oxygen transport in hemoglobin; Iodine is essential for thyroid hormone production; Sodium is vital for nerve impulse conduction.

Q33. Match the following nutrients with their chemical tests:

Column A (Nutrient)
Column B (Test)
1. Starch
A. Biuret test
2. Protein
B. Iodine test
3. Fat
C. Benedict’s test
4. Reducing sugar
D. Paper spot test

(a) 1-B, 2-A, 3-D, 4-C
(b) 1-A, 2-C, 3-B, 4-D
(c) 1-C, 2-D, 3-A, 4-B
(d) 1-D, 2-B, 3-C, 4-A
Answer: (a) 1-B, 2-A, 3-D, 4-C
Explanation: Starch is detected by iodine test (blue-black); Protein by Biuret test (violet); Fat by paper spot test (translucent spot); Reducing sugars by Benedict’s test (color change).

Q34. Match the following food components with their primary sources:

Column A (Component)
Column B (Source)
1. Vitamin C
A. Citrus fruits
2. Calcium
B. Dairy products
3. Iron
C. Green leafy vegetables
4. Vitamin B12
D. Animal products

(a) 1-A, 2-B, 3-C, 4-D
(b) 1-B, 2-C, 3-D, 4-A
(c) 1-C, 2-D, 3-A, 4-B
(d) 1-D, 2-A, 3-B, 4-C
Answer: (a) 1-A, 2-B, 3-C, 4-D
Explanation: Vitamin C is abundant in citrus fruits; Calcium in dairy products; Iron in green leafy vegetables; Vitamin B12 exclusively in animal products.

Q35. Match the following deficiency diseases with their symptoms:

Column A (Disease)
Column B (Symptom)
1. Scurvy
A. Soft and weak bones
2. Rickets
B. Bleeding gums
3. Anemia
C. Swollen neck
4. Goiter
D. Fatigue and weakness

(a) 1-B, 2-A, 3-D, 4-C
(b) 1-A, 2-C, 3-B, 4-D
(c) 1-C, 2-D, 3-A, 4-B
(d) 1-D, 2-B, 3-C, 4-A
Answer: (a) 1-B, 2-A, 3-D, 4-C
Explanation: Scurvy presents with bleeding gums; Rickets with soft bones; Anemia with fatigue; Goiter with neck swelling.

4. Advanced Double Fill in the Blank (Q41-Q50)

Q41. The process of converting glucose into glycogen is called ________, while the breakdown of glycogen to glucose is called ________.
A. Glycolysis, Glycogenesis
B. Glycogenesis, Glycogenolysis
C. Gluconeogenesis, Glycolysis
D. Glycogenolysis, Glycogenesis
Answer: B. Glycogenesis, Glycogenolysis
Explanation: Glycogenesis is the formation of glycogen from glucose for storage, while glycogenolysis is the breakdown of glycogen to release glucose when needed.

Q42. Vitamin ________ is essential for calcium absorption, while Vitamin ________ is crucial for blood clotting.
A. D, K
B. A, C
C. E, D
D. K, A
Answer: A. D, K
Explanation: Vitamin D enhances intestinal calcium absorption, while Vitamin K is necessary for synthesizing clotting factors.

Q43. The disease caused by niacin deficiency is ________, while thiamine deficiency causes ________.
A. Pellagra, Beri-beri
B. Scurvy, Rickets
C. Beri-beri, Pellagra
D. Rickets, Scurvy
Answer: A. Pellagra, Beri-beri
Explanation: Pellagra results from niacin (B3) deficiency, characterized by dermatitis, diarrhea, and dementia. Beri-beri is caused by thiamine (B1) deficiency.

Q44. ________ is stored in the liver and muscles as energy reserve, while ________ is stored in adipose tissue.
A. Glycogen, Fat
B. Protein, Carbohydrate
C. Fat, Glycogen
D. Vitamin, Mineral
Answer: A. Glycogen, Fat
Explanation: Glycogen is the carbohydrate storage form in liver and muscles, while triglycerides (fats) are stored in adipose tissue as long-term energy reserve.

Q45. The test for starch uses ________ solution, while the test for protein uses ________ reagent.
A. Iodine, Benedict’s
B. Biuret, Iodine
C. Iodine, Biuret
D. Benedict’s, Sudan III
Answer: C. Iodine, Biuret
Explanation: Iodine solution tests for starch (blue-black color), while Biuret reagent (copper sulfate in sodium hydroxide) tests for proteins (violet color).

5. Advanced Assertion–Reason (Q51-Q60)

Q51. Assertion (A): A teacher should include practical demonstrations of food tests in the curriculum.
Reason (R): Hands-on experiments help students understand biochemical concepts and develop scientific skills.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Explanation: Practical demonstrations make abstract concepts tangible, enhancing understanding and developing essential scientific inquiry skills, which aligns with constructivist learning principles.

Q52. Assertion (A): Consuming a variety of protein sources is important for vegetarians.
Reason (R): Plant proteins are incomplete and lack one or more essential amino acids.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Explanation: Most plant proteins are incomplete, so consuming different protein sources (like grains with legumes) ensures adequate intake of all essential amino acids through complementary proteins.

Q53. Assertion (A): Water-soluble vitamins need to be consumed daily.
Reason (R): They are not stored in the body and excess is excreted in urine.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Explanation: Water-soluble vitamins (B-complex and C) have limited storage capacity in the body, and excess amounts are rapidly excreted, necessitating regular dietary intake.

Q54. Assertion (A): Pasteurization does not make milk sterile.
Reason (R): Pasteurization kills pathogenic microorganisms but not all bacteria spores.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Explanation: Pasteurization uses mild heat treatment to destroy pathogens while preserving nutritional quality, but it doesn’t eliminate all microorganisms, particularly heat-resistant spores.

Q55. Assertion (A): Iron requirements are higher for adolescent girls than boys.
Reason (R): Girls experience monthly blood loss during menstruation, increasing iron needs.
(a) Both A and R are true, and R is the correct explanation of A.
(b) Both A and R are true, but R is NOT the correct explanation of A.
(c) A is true, but R is false.
(d) A is false, but R is true.
Answer: (a) Both A and R are true, and R is the correct explanation of A.
Explanation: Menstrual blood loss significantly increases iron requirements in adolescent girls and women to prevent iron deficiency anemia.

6. Advanced Statement is True or Not Based (Q61-Q65)

Q61. Consider the following statements about balanced diet:
(i) It provides all essential nutrients in adequate amounts
(ii) It remains constant throughout life
(iii) It varies with age, gender and activity level
(iv) It includes only energy-giving foods

Which statements are correct?
(a) (i) and (ii)
(b) (i) and (iii)
(c) (ii) and (iv)
(d) (iii) and (iv)
Answer: (b) (i) and (iii)
Explanation: A balanced diet provides all essential nutrients adequately and varies based on individual factors like age, gender, and physical activity level.

Q62. Consider the following statements about vitamins:
(i) All vitamins provide energy
(ii) Fat-soluble vitamins can be stored in the body
(iii) Vitamin C helps in iron absorption
(iv) Vitamin D deficiency causes scurvy

Which statements are correct?
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (iii) and (iv)
(d) (i) and (iv)
Answer: (b) (ii) and (iii)
Explanation: Vitamins don’t provide energy; fat-soluble vitamins (A, D, E, K) are stored; vitamin C enhances iron absorption; vitamin D deficiency causes rickets, not scurvy.

Q63. Read the statements about food preservation:
(A) Refrigeration slows down microbial growth
(B) Dehydration removes water needed by microorganisms
(C) Salt and sugar create hypotonic environment
(D) Pasteurization makes milk sterile

Which statements are correct?
(a) A and B
(b) B and C
(c) C and D
(d) A and D
Answer: (a) A and B
Explanation: Refrigeration slows microbial metabolism; dehydration removes essential water; salt/sugar create hypertonic environment; pasteurization doesn’t achieve sterility.

7. Questions with More than One Answer (Q66-Q70)

Q66. Which of the following are functions of proteins?
(a) Enzyme catalysis
(b) Oxygen transport
(c) Immune defense
(d) Energy storage
Answer: (a), (b), and (c)
Explanation: Proteins function as enzymes (catalysis), hemoglobin (oxygen transport), and antibodies (immune defense), but fats are the main energy storage molecules.

Q67. Which minerals are important for bone health?
(a) Calcium
(b) Phosphorus
(c) Iron
(d) Magnesium
Answer: (a), (b), and (d)
Explanation: Calcium and phosphorus are major bone components, magnesium is involved in bone metabolism, while iron is primarily for oxygen transport.

Q68. Which vitamins have antioxidant properties?
(a) Vitamin A
(b) Vitamin C
(c) Vitamin E
(d) Vitamin K
Answer: (a), (b), and (c)
Explanation: Vitamins A, C, and E function as antioxidants, protecting cells from oxidative damage, while vitamin K is primarily involved in blood clotting.

Q69. Which food preservation methods inhibit microbial growth by controlling temperature?
(a) Refrigeration
(b) Pasteurization
(c) Dehydration
(d) Adding preservatives
Answer: (a) and (b)
Explanation: Refrigeration slows microbial growth through low temperature, while pasteurization uses controlled heat to destroy pathogens.

Q70. Which nutrients provide energy to the body?
(a) Carbohydrates
(b) Proteins
(c) Fats
(d) Vitamins
Answer: (a), (b), and (c)
Explanation: Carbohydrates, proteins, and fats are macronutrients that provide energy (4, 4, and 9 kcal/g respectively), while vitamins are micronutrients that don’t provide energy.

COMPLETE LIST OF QUESTIONS FROM UPLOADED DOCUMENTS

Q1. [PYQ] After school, Breena daily cuts cucumbers from an open nearby roadside shop. After one week, she gets suffered from high fever. What could be the correct reason for the above treatment?
(1)A and D
(2)A and B
(3)A, B and C
(4)A, C and D
Answer: (2) A and B (Assuming A is Unhygienic food and B is Food exposed to dust and flies, based on the text in the document).
Explanation: The document’s theory section states that “Eating uncovered foods items and drinking supplies, vegetables and fruits juice exposed to dust and flies should be avoided.” This directly links the scenario to the reason.

Q2. [PYQ] Given below are some food items:

A. Spilled and roasted potato,

B. Boiled and chewed rice,

C. A slice of bread,

D. Sweet potato.

Which of the above food items will give blue-black colour when tested with iodine solution?
(1)A and B only
(2)A and C only
(3)B and C only
(4)A, B and C only
Answer: (4) A, B and C only
Explanation: The blue-black colour with iodine indicates starch. Potato (A), rice (B), and bread (C, made from wheat) are all starchy foods.

Q3. [PYQ] Radhika’s gums were often bleeding and her wounds were taking longer time to heal. Her diet could be deficient in which vitamin?
(1)Vitamin A
(2)Vitamin B
(3)Vitamin C
(4)Vitamin D
Answer: (3) Vitamin C
Explanation: Bleeding gums and slow wound healing are classic signs of Scurvy, caused by Vitamin C deficiency.

Q4. [PYQ] Which one of the following is used as preservative?
(1)Sodium carbonate
(2)Ammonium sulphate
(3)Sodium benzoate
(4)Copper sulphate
Answer: (3) Sodium benzoate
Explanation: The document’s theory on preservation lists “Sodium Benzoate” as a chemical preservative.

Q5. [PYQ] Which of the following nutrients are present in milk?
(1)Protein, Fat, Vitamin C
(2)Protein, Fat, Vitamin D
(3)Protein, Calcium, Vitamin C
(4)Carbohydrates, Vitamin C, Iron
Answer: (2) Protein, Fat, Vitamin D
Explanation: The document states: “Milk is considered as balanced food and is rich source of protein, calcium, vitamin D.”

Q6. [PYQ] Deficiency of Vitamin X causes bleeding of gums. This vitamin is essential for absorption of mineral Y and Y is found in food Z. Identify X, Y and Z.
(1)X-Vitamin B, Y-Calcium, Z-Green leafy vegetable
(2)X-Vitamin A, Y-Phosphorus, Z-Dairy products
(3)X-Vitamin D, Y-Calcium, Z-Milk products
(4)X-Vitamin C, Y-Iron, Z-Citrus fruits
Answer: (4) X-Vitamin C, Y-Iron, Z-Citrus fruits
Explanation: Vitamin C (X) deficiency causes bleeding gums (Scurvy). Vitamin C enhances iron (Y) absorption. Citrus fruits (Z) are a rich source of Vitamin C.

Q7. [PYQ] Which of the following sources of carbohydrate contains gluten, a component which can cause allergy to some people?
(1)Jowar
(2)Wheat
(3)Raggi
(4)Sugar
Answer: (2) Wheat
Explanation: The document’s theory on carbohydrates states: “Gluten is a component of wheat (carbohydrate) which can cause allergy to some people.”

Q8. [PYQ] Deficiency of which vitamin leads to excessive bleeding from a wound?
(1)C
(2)B-complex
(3)D
(4)K
Answer: (4) K
Explanation: The document’s table on vitamins lists the function of Vitamin K as “Normal blood clotting.” Its deficiency would lead to excessive bleeding.

Q9. [PYQ] A teacher puts a leaf in a test tube and puts spirit (alcohol) in it. Now he heats the test tube till all the green colour comes out. Then he takes out the leaf and puts some iodine solution on it. The students write the following statements in their notebook. (A) The leaf turns blue-black in colour (B) The leaf contains starch. Which of the following statement is correct?
(1)A is observation, B is inference
(2)A is inference, B is observation
(3)Both A and B are observed
(4)Both A and B are inferred
Answer: (1) A is observation, B is inference
Explanation: The colour change is directly seen (observation). Concluding the presence of starch is an interpretation of that observation (inference).

Q10. [EXERCISE] Consider the following statements about fats:

A. Fats are soluble in organic solvents.

B. Fats can only be obtained from natural sources.

C. Excess of saturated fats in diet may lead to heart attack.

Which of the statements given above is/are correct?
(1)Only A
(2)A and C
(3)A and B
(4)None of the above
Answer: (2) A and C
Explanation: Fats are soluble in organic solvents (A is correct). Fats can be synthetically produced (B is incorrect). Excess saturated fats increase heart disease risk (C is correct).

Q11. [EXERCISE] Mother’s milk is preferred for infants because it contains:
(1)More fats and less lipids
(2)Less fats and more lipids
(3)Less fats and less lipids
(4)More fats and more lipids
Answer: The options are scientifically flawed as fats are lipids.
Explanation: This question contains an error. A teacher should identify that the options are meaningless. The true value of mother’s milk lies in its antibodies and ideal nutrient balance for infants.

Q12. [EXERCISE] In a human body, fats are stored in:
(1)adipose tissues
(2)Bone cells
(3)epidermis cells
(4)epithelial cells
Answer: (1) adipose tissues
Explanation: The document states: “Fats are stored in the adipose tissue.”

Q13. [EXERCISE] Which one of the following acids is present in vitamin C?
(1)Oleic acid
(2)Ascorbic acid
(3)Lactic acid
(4)Folic acid
Answer: (2) Ascorbic acid
Explanation: Ascorbic Acid is the chemical name for Vitamin C.

Q14. [EXERCISE] Which of the following deficiencies in food cause Kwashiorkor disease?
(1)Protein
(2)Fats
(3)Vitamin A
(4)Vitamin-C
Answer: (1) Protein
Explanation: The document states: “The deficiency of proteins in children may lead to the disease, called Kwashiorkor.”

Q15. [EXERCISE] Consider the following

statements.

  • A. Vitamins are complex organic molecules.
  • B. Vitamins are required in small amounts for our life.
  • C. Water soluble vitamins can be stored in your body.

Which of the statements given above is/are correct?
(1)A and B
(2)A and C
(3)B and C
(4)Only C
Answer: (1) A and B
Explanation: A and B are correct. C is incorrect because water-soluble vitamins are not stored in the body.

Q16. [EXERCISE] Which one of the following is not correctly matched?

1. Vitamin B₁₂ – Pernicious anaemia
2. Vitamin B₁ – Beri-beri
3. Vitamin C – Scurvy
4. Vitamin B₃ – Pellagra
Answer: All the given pairs are correct. The question might be incomplete. A common incorrect match would be Vitamin D – Scurvy.
Explanation: This question checks knowledge of vitamin-deficiency pairs. All listed are standard, correct pairs.

Q18. [EXERCISE] Select from the following a group of diseases caused by deficiency of minerals:
(1)Goitre, Kwashiorkor, Osteomalacia
(2)Goitre, Anaemia, Kwashiorkor
(3)Kwashiorkor, Anaemia, Osteomalacia
(4)Goitre, Anaemia, Osteomalacia
Answer: (4) Goitre, Anaemia, Osteomalacia
Explanation:Goitre (Iodine), Anaemia (Iron), Osteomalacia (Calcium/Vitamin D). Kwashiorkor is caused by protein deficiency.

Q19. [EXERCISE] Read the given statements and select the correct option.

Statement A: Anaemia is a deficiency disease of iron.

Statement B: Anaemia causes general weakness and fatigue.
(a)Both statements A and B are incorrect
(b)Statement A is correct, but Statement B is incorrect
(c)Statement B is correct, but Statement A is incorrect
(d)Both statements A and B are correct
Answer: (d) Both statements A and B are correct
Explanation: The most common anaemia is due to iron deficiency, and a primary symptom is weakness/fatigue from reduced oxygen in the blood.

Q21. [EXERCISE] Meena has 20 kg of green leafy vegetables, she decided to store these vegetables for further use. Which of the following storage method should be used by her so that vegetables can stay longer?
(1)Dry storage
(2)Cold storage
(3)Wet storage
(4)Hot storage
Answer: (2) Cold storage
Explanation: The document states: “The perishable foods are stored in cold… place.” Green leafy vegetables are highly perishable.