Q5 of 386 Page 161

(a) Identify the figure. What is its function

(b) Label V and W


(c) Label X, Y and Z


(d) W loses its nucleus in the mature state, still it remains alive. Explain how


(a) It is a section of phloem, a complex tissue. Phloem transports food from leaves to the other parts of the plant.

(b) V - Phloem parenchyma; W- Seive tube


(c) X - Sieve plate; Y-Companion cell; Z - Sieve pores.


(d) Sieve tube are associated with companion cells. A mature sieve tube is living but it lacks a nucleus. Companion cells are living and associated with the sieve tubes. Living state of the mature sieve tube cells is regulated by nucleated cornpanion cells. These cells supply the RNA and proteins that keep the sieve tube alive. is associated with companion cells.


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3

What will happen if

(a) Apical meristem is damaged or cut?


(b) Cork is not formed in older stems and roots.


(c) Lymph is not returned to blood?

 4




(a) Identify Figure A, B and C


(b) Which one of them has heavy deposition of lignin?


(c) Which one of them provides both mechanical strength as well as flexibility?


(d) Which one of them can be modified to form air cavities in awuatic plants?


(e) Which one of them is commercially exploited to obtain Hemp and Jute?

 6



(a) Identify figures A and B.


(b) Which is called tesselated and payement epitheliurn?


(c) Which one lines the gastrointestinal tract and epiglottis ?


(d) Which one allows diffusion of substances ?

 7


(a) Identify figures A and B.


(b) Label X, Y and Z.


(c) Which one act as impulse booster?


(d) Which one is under control our will?