Selected MCQ

Current Question
Stomata primarily regulate:
  • A. Seed dispersal
  • B. Gas exchange and transpiration
  • C. Protein synthesis
  • D. Root pressure directly only
Correct Answer: B
Explanation:
Guard cells control stomatal aperture for (CO_2), (O_2), and water vapor exchange.
Related Question 1
Which hormone regulates blood sugar?
  • A. Thyroxine
  • B. Insulin
  • C. Adrenaline
  • D. Melatonin
Correct Answer: B
Explanation:
Insulin lowers blood glucose levels.
Related Question 2
Which structure regulates passage of substances into cell?
  • A. Nucleus
  • B. Cell membrane
  • C. Mitochondria
  • D. Ribosome
Correct Answer: B
Explanation:
Plasma membrane controls transport.
Related Question 3
The Hadley cell is primarily driven by:
  • A. Polar cooling only
  • B. Differential solar heating between equator and subtropics
  • C. Tidal friction
  • D. Lunar gravity
Correct Answer: B
Explanation:
Strong equatorial heating drives rising air and tropical atmospheric overturning.
Related Question 4
In the rock cycle, basalt can transform into amphibolite primarily by:
  • A. Weathering only
  • B. Metamorphism
  • C. Sublimation
  • D. Bioturbation
Correct Answer: B
Explanation:
Increased pressure and temperature alter basalt mineralogy into metamorphic assemblages.
Related Question 5
Seafloor spreading occurs primarily at:
  • A. Transform boundaries
  • B. Convergent boundaries
  • C. Divergent boundaries
  • D. Hotspot volcanoes only
Correct Answer: C
Explanation:
New oceanic crust forms where plates move apart at mid-ocean ridges.