Biological Classification And System Of Classification Question 554
Question: Heterocyst constitutes a
Options:
A) Weakest link in trichome
B) Strongest link in trichome
C) In some trichomes it is a strong link
D) It is not linked at all
Show Answer
Answer:
Correct Answer: A
Solution:
Heterocysts are specialized nitrogen-fixing cells formed during nitrogen starvation by some filamentous cyanobacteria, such as Nostoc punctiforme, Cylindrospermum stagnale, and Anabaena sphaerica.
They fix nitrogen from dinitrogen ($N_2$) in the air using the enzyme nitrogenase, in order to provide the cells in the filament with nitrogen for biosynthesis.
Trichomes are hair cells or leaf hairs derived from specialized epidermal cells on leaf or stem surfaces.
These hairs are produced as a result of the outward growth of one or more epidermal cells.
Epidermal tissues give rise to appendages (trichomes) such as spines, hairs or glands that give plant leaves or stems distinctive textures.
BETA
