STEM QUIZ

1. Cell Biology (The Foundation)

• Life Characteristics: Living organisms perform respiration, excretion, and reproduction. Crystallization is non-living.
• Cell Structure:
  • Control & Genetics: The nucleus stores genetic information.
  • Energy: Mitochondria produce energy (powerhouse).
  • Protection & Transport: The cell membrane regulates entry/exit of substances. The cell wall provides structural support (plants only).
  • Storage: Vacuoles store water and nutrients.

2. Plant Physiology

• Photosynthesis: Converts ${\mathrm{CO}}_2$, water, and light into glucose and oxygen.
• Transport Systems:
  • Xylem: Moves water/minerals up from roots.
  • Phloem: Moves food (sugars) throughout the plant.
• Water Movement:
  • Root Absorption: Roots take in water via osmosis and capillary action.
  • Transpiration: Water loss as vapor from leaves.
  • Osmosis: Movement of water from high to low concentration across a membrane.

3. Human Physiology: Digestion & Excretion

• Digestion Process: Breaks down complex food (hydrolysis).
  • Proteins $\to$amino acids.
  • Fats $\to$ fatty acids/glycerol (aided by bile from the liver/gallbladder).
  • Carbohydrates $\to$ glucose.
• Key Organs:
  • Stomach: Grinds food/secretes enzymes.
  • Small Intestine: Primary site for nutrient absorption.
  • Large Intestine: Absorbs water.
• Excretion: The kidneys filter blood to produce urine, while the liver processes toxins.

4. Human Physiology: Circulation & Respiration

• Circulation: The heart pumps blood transporting nutrients, gases, and waste. Bone marrow generates blood cells, and the spleen filters blood.
• Respiration: Involves gas exchange (${\mathrm{O}}_2$/${\mathrm{CO}}_2$) in the alveoli. The breathing rate is controlled by the medulla oblongata.

5. Human Control & Coordination (Nervous & Endocrine)

• Nervous System:
  • Neuron: Signals received by dendrites, transmitted by axons (insulated by myelin), and jump across synapses.
  • Brain:
    • Cerebrum: Voluntary actions, learning, senses.
    • Cerebellum: Balance and posture.
    • Medulla Oblongata: Involuntary actions (heart rate, breathing).
    • Hypothalamus: Regulates temperature and emotions.
  • The Eye: Light enters through the cornea and pupil (controlled by iris), focused by the lens onto the retina.
• Endocrine System (Hormones):
  • Pituitary: Growth hormone (master gland).
  • Thyroid: Metabolism.
  • Adrenal: Adrenaline (stress).
  • Pancreas: Insulin (blood sugar).
  • Others: Pineal (sleep), thymus (immunity), parathyroid (calcium).