Section A: High Order Thinking Skills (HOTS)
- Artificial Kidney: What is the principle behind Hemodialysis? How is the dialyzing
fluid different from blood plasma? (Same composition but no nitrogenous waste).
- Lymphatic Role: Besides immunity, Lymph plays a crucial role in digestion. Explain
how lymph aids in the absorption of digested fats. (Lacteals).
- Photosynthesis Logic: Desert plants take up Carbon dioxide at night and modify the
pathway of photosynthesis. Explain how their mechanism (CAM pathway) differs from normal plants to
conserve water.
- ATP Calculation: Why is aerobic respiration considered more efficient than
anaerobic respiration in terms of energy currency? (Compare ATP yield: 38 vs 2).
- What prevents backflow of blood inside the heart during contraction? What would happen if valves
were absent?
Section B: Experimental Competency (Case Studies)
Case I: Sunlight for Photosynthesis. A student takes a potted plant and covers a part of
a leaf with a black strip. The plant is then kept in sunlight for 6 hours. The leaf is plucked,
de-colorized with alcohol, and tested with iodine.
- Why is the leaf boiled in alcohol in a water bath? (Direct heating can catch fire).
- What color will the covered part of the leaf show with iodine? Why?
- What color will the exposed part show? What does it indicate?
- What is the conclusion of this experiment?
Case II: Essentiality of CO2. Two potted plants are kept in dark for 72 hours. Then they
are placed in separate bell jars A and B. Jar A contains a watch glass with Potassium Hydroxide (KOH).
Both are kept in sunlight.
- What is the function of keeping plants in dark for 72 hours? (De-starching).
- What is the role of KOH in Jar A? (Absorbs CO2).
- In which jar will the leaf show a positive starch test? Why?
- Draw the experimental setup.
Section C: Miscellaneous & Olympiad Level
- Root Pressure vs Transpiration Pull: Water moves up in tall trees due to
Transpiration Pull. However, at night, when stomata are closed, how does water move into the roots?
Explain the role of Root Pressure.
- Herbivore Gut: Rabbits eat grass and Tigers eat meat. Explain structurally how
their alimentary canals differ to suit their diets. (Cellulose digestion requires longer track).
- Leakage Control: What is the mechanism of clotting? Why is Vitamin K important for
it?
- How is the breathing rate controlled by the brain? (CO2 concentration in blood).
- Explain why urine is yellow in color. (Urochrome pigment).
