Name the following by choosing the correct option:
Permanently open structures seen on the barks of old woody stems:
Topic: Lenticels
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Pick an option and check your answer. The full worked answer is below either way.
Answer
(c) Lenticels.
LENTICELS are small raised pores in the bark of woody stems, filled with loosely packed cells. They are PERMANENTLY OPEN — which is the key word in the question.
Why they matter: a thick corky bark is impermeable, so without them the living cells beneath could not exchange oxygen and carbon dioxide with the air. They also allow a small amount of transpiration, called LENTICULAR transpiration.
The three kinds of pore, distinguished by where they are and whether they can close: STOMATA — on leaves; can OPEN AND CLOSE, controlled by guard cells HYDATHODES — at leaf tips and margins; permanently open, but give out LIQUID water (guttation) LENTICELS — on woody STEMS; permanently open The question specifies BARKS of woody stems, which settles it.
Lenticels.