Organisms and Populations Question 12
12. In which one of the following is nitrogen not a constituent?
(a) Pepsin
(b) Idioblast
(c) Bacteriochlorophyll
(d) Invertase
Show Answer
Answer : b
Hints & Solutions
(b) Raphides are needle-shaped crystals of calcium carbonate or calcium oxalate found in specialized plant cells called idioblasts. It is believed that the raphides are a defense mechanism against plant predators, as they are likely to tear the soft tissues of the throat or esophagus of a plant predator chewing on the plant’s leaves. They are non-nitrogenous substances.
