Transportation

• Human circulatory system — heart, blood vessels, blood.
• Double circulation — pulmonary and systemic circuits.
• Blood components — plasma, RBC, WBC, platelets.
• Plant transport — xylem (water + minerals up); phloem (food up/down).
• Transpiration — water loss from leaves drives xylem flow.

1. Heart — four chambers; left side oxygenated blood to body; right to lungs.
2. Arteries — away from heart, thick walls; veins — to heart, valves prevent backflow.
3. Capillaries — exchange between blood and tissues.
4. Blood groups — A, B, AB, O; Rh factor; universal donor O (RBC context).
5. Xylem — tracheids, vessels; unidirectional upward from roots.
6. Phloem — sieve tubes + companion cells; translocation of sucrose.
7. Transpiration pull — evaporation from leaves pulls water column in xylem.
8. Root pressure — contributes especially at night.
9. Lymph — tissue fluid drainage; fat transport from intestine.
10. NCERT diagrams — section of heart; vascular bundle in stem.

Path of water from soil to leaf (brief)

Soil water → root hair → root xylem → stem xylem → leaf xylem → mesophyll → evaporates from stomata (transpiration).
Minerals dissolved in water travel same xylem route.
Transpiration pull main driving force in tall plants.
Conclusion: xylem unidirectional ascent of sap.

• Thinking phloem transports water (xylem does).
• Misconception: arteries always carry oxygenated blood (pulmonary artery carries deoxygenated).
• Confusing transpiration with translocation.
• Forgetting platelets role in clotting.
• Assuming single circulation in humans (double circulation).

• Name vessels that carry blood away from heart.
• Function of xylem and phloem?
• What drives transpiration pull?
• How many chambers in human heart?

Open the Practice tab for graded questions on Transportation.