Q139
Coral reefs are formed by ________
A.
Volcanic rocks
B.
Marine sediments
C.
Chlorine material precipitated from sea water
D.
Tiny colonial marine animals which construct limestone skeleton material
AnswerAnswer: Option D
Solution
Answer: Option D
Solution:
Coral reefs are formed by tiny colonial marine animals which construct limestone skeleton material. Massive reef structures are formed when each individual stony coral organism or polyp secretes a skeleton of calcium carbonate.