Selected MCQ

Current Question
A keystone species is one whose removal causes:
  • A. No measurable ecological change
  • B. A disproportionately large effect on community structure
  • C. Only a reduction in primary productivity
  • D. Immediate extinction of all species
Correct Answer: B
Explanation:
Keystone species have ecological impacts much larger than expected from their abundance.
Related Question 1
Which species is isoelectronic with Ne?
  • A. Na⁺
  • B. Mg²⁺
  • C. F⁻
  • D. All of the above
Correct Answer: D
Explanation:
All have 10 electrons like neon.
Related Question 2
Which gas causes global warming?
  • A. Oxygen
  • B. Nitrogen
  • C. CO₂
  • D. Helium
Correct Answer: C
Explanation:
CO₂ traps heat.
Related Question 3
Which species has highest electronegativity?
  • A. Oxygen
  • B. Fluorine
  • C. Chlorine
  • D. Nitrogen
Correct Answer: B
Explanation:
Fluorine is most electronegative.
Related Question 4
Which species has highest oxidation state?
  • A. MnO₂
  • B. Mn₂O₇
  • C. MnO
  • D. Mn₃O₄
Correct Answer: B
Explanation:
Mn in Mn₂O₇ is +7.
Related Question 5
Which boundary causes earthquakes?
  • A. Divergent
  • B. Convergent
  • C. Transform
  • D. All
Correct Answer: D
Explanation:
All plate boundaries can generate earthquakes.