Home
Class 12
BIOLOGY
Xylem fibres posses obliterated central ...

Xylem fibres posses obliterated central lumen due to very thick walls. This helps to perform the function of

A

Conduction

B

Storage of ffod

C

Mechanical support

D

Both (2) & (3)

Text Solution

Verified by Experts

The correct Answer is:
C
Promotional Banner

Similar Questions

Explore conceptually related problems

The central lumens are obliterated in

Assertion : A typical microsporangium of angiosperms is generally surrounded by four wall layers - epidermis, endothecium, middle layers and tepetum. Reason : The outer three wall layers perform the function of protection and help in dehiscence of anther to release the pollen.

Select true statements - (A) Phloem fibres are generally absent in the primary phloem. (B) Root hairs help in absorption of water and minerals from the soil (c ) Trichome help in preventing water loss due to transpiration.

A monatomic ideal gas is contained in a rigid container of volume V with walls of total inner surface area A, thickness x and thermal conductivity K. The gas is at an initial temperature t_(0) and pressure P_(0) . Find the pressure of the gas as a function of time if the temperature of the surrounding air is T_(s) . All temperature are in absolute scale.

A vessel ABCD of 10 cm width has two small slits S_(1) and S_(2) sealed with idebtical glass plates of equal thickness. The distance between the slits is 0.8 mm . POQ is the line perpendicular to the plane AB and passing through O, the middle point of S_(1) and S_(2) . A monochromatic light source is kept at S, 40 cm below P and 2 m from the vessel, to illuminate the slits as shown in the figure. Calculate the position of the central bright fringe on the other wall CD with respect of the line OQ . Now, a liquid is poured into the vessel and filled up to OQ . The central bright fringe is fiund to be at Q. Calculate the refractive index of the liquid.

The wall of Human heart is thick due to presence of :-

[A]: In the hydrophytes the Xylem is not differentiated into different types of cells. [R]: Xylem provides support and helps in the conduction of water which is not very important in hydrophytes

Assertion : Contraction of a muscle fibre takes place by the sliding of the thin filaments over the thick filaments. Reason : The central part of thick filament is not overlapped by thin filaments in a resting state.

Read the assertion and reason carefully to mark the correct option out of the option given below: Assertion: Thick layers of muscles are present in the wall of alimentary canal. Reason: These muscles help in the mixing of food materials with the enzymes coming from different glands in the alimentary canal.

Which of the following statements regarding the structure of microsporagium are correct ? (i) Microsporangium is generally surrounded by four wall layers-epidermis, endothecium, middle layers and tapetum (ii) outer three layers perform functions of protection and dehiscence of anthers. (iii) Cells of tapetum undergo meiosis and produce micropore tetrads.