Unit 1: Life Processes and Basic
Organisms
Life Processes
1. What defines a living organism?
o An organism must exhibit seven life processes: Movement, Respiration,
Sensitivity, Growth, Reproduction, Excretion, Nutrition.
2. Differentiate between egestion and excretion.
o Egestion: Removal of undigested food as feces.
o Excretion: Removal of metabolic waste like urea, CO₂, and sweat.
Cell Structure
3. List the main organelles in a plant cell and their functions.
o Cell Wall: Supports and protects.
o Chloroplast: Photosynthesis (contains chlorophyll).
o Vacuole: Maintains turgidity.
o Mitochondria: Site of aerobic respiration.
o Cytoplasm: Site of metabolic reactions.
o Nucleus: Controls cell activities and division.
4. What is the function of the mitochondria?
o It is the site of aerobic respiration, releasing energy for cellular activities.
5. How are animal cells different from plant cells?
o Animal cells lack a cell wall, chloroplasts, and large permanent vacuoles.
Specialized Cells
6. What is the function of red blood cells?
o Transport oxygen using hemoglobin.
7. What are the adaptations of root hair cells?
o Long extensions for a large surface area to absorb water and minerals.
8. How do ciliated epithelial cells protect the respiratory system?
o They secrete mucus to trap dust/pathogens and use cilia to sweep mucus out.
Nutrition
9. What are the macronutrients, and what do they do?
o Carbohydrates: Energy source.
o Proteins: Growth and repair.
o Fats/Lipids: Energy storage, insulation, and cell membranes.
10. Describe the test for proteins.
o Add Biuret solution; a color change from blue to purple indicates protein
presence.
11. List sources and deficiency symptoms of Vitamin A.
o Sources: Carrots, egg yolk.
o Deficiency: Night blindness, eye infections.
12. What factors affect energy requirements in humans?
o Age, activity level, gender, pregnancy, and environmental conditions.
Enzymes
13. What are enzymes, and why are they specific?
o Enzymes are proteins that catalyze reactions. They are specific because their
active site matches only one substrate.
14. What factors affect enzyme activity?
o Temperature, pH, and substrate concentration.
Respiration
15. Compare aerobic and anaerobic respiration.
o Aerobic: Glucose + Oxygen → CO₂ + Water + Energy.
o Anaerobic: Glucose → Lactic Acid + Energy (less efficient).
16. What causes oxygen debt during exercise?
o Accumulation of lactic acid in muscles requires oxygen to break it down.
Unit 2: Animal Systems
Respiratory System
17. What are the adaptations of alveoli for gas exchange?
o Large surface area, thin walls, rich blood supply.
18. Describe the process of inhalation.
o Diaphragm contracts, ribcage moves up/out, lung volume increases, pressure
decreases, air enters.
19. List three hazards of smoking.
o Nicotine: Addictive; increases heart rate.
o Tar: Causes lung cancer and damages cilia.
o Carbon monoxide: Reduces oxygen delivery to tissues.
Digestive System
20. What is the role of bile in digestion?
o Emulsifies fats, increasing their surface area for enzyme action.
21. What are the adaptations of the small intestine for absorption?
o Long length, villi/microvilli for increased surface area, rich blood supply, thin
walls.
22. What is peristalsis?
o Wave-like muscle contractions that move food through the digestive tract.
Circulatory System
23. What are the functions of the circulatory system?
o
Transport nutrients, oxygen, waste, and hormones; regulate temperature;
immune defense.
24. Name and describe the three types of blood vessels.
o Arteries: Thick walls, high pressure, carry oxygenated blood (except
pulmonary artery).
o Veins: Thin walls, valves to prevent backflow, carry deoxygenated blood
(except pulmonary vein).
o Capillaries: One-cell-thick walls, facilitate exchange of substances.
25. What is the function of platelets?
o Blood clotting.
Skeletal System
26. What are the functions of the skeleton?
o Support, movement, protection, blood cell production.
27. Name the types of joints and examples.
o Fixed (skull), hinge (knee/elbow), ball-and-socket (hip/shoulder).
Muscular System
28. What are antagonistic muscles?
o A pair of muscles where one contracts while the other relaxes (e.g., biceps and
triceps).
29. What are the three types of muscle tissues?
o Skeletal: Voluntary, attached to bones.
o Cardiac: Involuntary, found in the heart.
o Smooth: Involuntary, found in organs like intestines.
Nervous System
30. What are the two main parts of the nervous system?
o Central Nervous System (CNS) and Peripheral Nervous System (PNS).
31. What is the function of the sensory system?
o Provides information about surroundings via sense organs (eyes, ears, skin,
etc.).
Endocrine System
32. What is the role of insulin?
o Regulates blood sugar by promoting glucose uptake in cells.
33. What does adrenaline do?
o Prepares the body for 'fight or flight' by increasing heart rate and directing
blood to muscles.
Excretory System
34. What are the main organs of the excretory system and their roles?
o Kidneys: Filter urea and waste from blood.
o Bladder: Stores urine.
o Urethra: Passes urine out of the body.