Tag: root

Questions Related to root

Root hairs are found

botany root - external morphology morphology of the root root system in plants root

  1. In the zone of maturation

  2. Adventitious roots

  3. On the root cap

  4. Apical meristem

Show answer
Correct Option: A
Explanation:
A root hair, or absorbent hair, the rhizoid of a vascular plant, is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root.
Root hair cells vary between 15 and 17 micrometres in diameter, and 80 to 1,500 micrometres in length. 
They are found only in the zone of maturation, and not the zone of elongation, possibly because any root hairs that arise are sheared off as the root elongates and moves through the soil.

The function of root cap is to

botany root - external morphology morphology of the root root system in plants root

  1. Protect the root tip

  2. Protect the root hairs

  3. Cover the root

  4. Growth of the root

Show answer
Correct Option: A
Explanation:
  • At the terminal region of the root tip is a cup-like or a thimble-like structure called the root cap which is formed from calyptrogen (specialized internal meristematic cells).
  • It is also known as calyptra.
  • It contains statocytes which help in gravity perception in plants that help in the growth of root towards the soil.
  • The root apex is protected by this root cap as it penetrates into the soil.
The root cap is formed by a specialized internal meristematic which is part of the histogen and is called calyptrogen
So, the correct answer is 'Protect the root tip'

Root cap regenerates$/$ dead torn cells of root cap are replaced by the activity of

botany root - external morphology morphology of the root root system in plants root

  1. Plerome

  2. Dermatogen

  3. Calyptrogen

  4. Periblem

Show answer
Correct Option: C
Explanation:
  • At the terminal region of the root tip is a cup-like or a thimble-like structure called the root cap which is formed from calyptrogen (specialized internal meristematic cells).
  • The root apex is protected by this root cap.
  • The root cap is formed by a specialized internal meristematic which is part of the histogen and is called calyptrogen.
  • The calyptrogen continuously divide to form the root cap and also helps in the regeneration of root cap in case of injury.
  • So, the correct answer is 'Calyptrogen'.

Quiescent centre shows

botany root - external morphology morphology of the root root system in plants root

  1. Rapid divisions

  2. High metabolic activity

  3. Little meristematic activity

  4. Development of lateral appendages

Show answer
Correct Option: C
Explanation:
  • The quiescent centre is that part of the root-promeristems that contains the initials of epidermis, cortex and stele.
  • These cells divide less frequently as they are inactive and are present at the pole of cortex and stele.
  • The cells with QC have small dictyosomes, nuclei and nucleoli with little cytoplasm.
  • These cells also have little endoplasmic reticulum, mitochondria and contain low concentrations of RNA, DNA and protein than the other cells of the root apex.
  • So, the correct answer is 'Little meristematic activity'.

Casparian thickenings are found in the cells of

botany root - external morphology morphology of the root root system in plants root

  1. Pericycle of the root

  2. Endodermis of the root

  3. Pericycle of the stem

  4. Endodermis of the stem

Show answer
Correct Option: B
Explanation:

The radial walls of the endodermis are marked by characteristic thickenings, called the casparian strips. These thickenings contain lignin, suberin and phenolic oxidation products that gives the strips a dark colour. The endodermis is a typical cell layer of roots. In roots, it is localized at the periphery of the vascular cylinder. 

Root hairs develop from

botany root - external morphology morphology of the root root system in plants root

  1. Region of maturation

  2. Zone of elongation

  3. Meristematic region

  4. Region of mature cells

Show answer
Correct Option: A
Explanation:

This region represents the zone of differentiation or maturation because different types of primary tissues differtiate or mature in this region. Root hair zone is 1 - 6 cm in length. Most of the water absorption occurs in this region. Some of the outer cells of this zone give rise to lateral tubular outgrowths called root hairs. The root hairs increase the exposed surface of the root for absorption.

Root hairs occur in the zone of 

botany root - external morphology morphology of the root root system in plants root

  1. Cell division

  2. Cell elongation

  3. Cell maturation

  4. Mature cells

Show answer
Correct Option: C
Explanation:

Root consist of four parts:-

  1.  Root cap which protects the root and secrete mucilage which lubricates the root.
  2. Region of meristematic activity where apical meristem is present and increase the length of root.
  3. Region of elongation where the newly-formed cells increase in length, thereby lengthening the root.
  4. Region of maturation that bears unicellular root hairs which increases the surface area and helps in the absorption of water.
So, the correct option is 'Cell maturation'.

When a plant is not reproducing, most of its cytokinins are produced in its:

botany root - external morphology morphology of the root root system in plants root

  1. Leaves

  2. Lateral buds

  3. Roots

  4. Shoot apex

Show answer
Correct Option: C
Explanation:

The substance was named Cytokinin and it is involved in cell division and in the making of new plant organs, like a root or a shoot. Cytokinins are produced in the root apical meristems (very tip of the roots) and travel upward hitching a ride with water and traveling up the stem through the xylem.

So, the correct option is 'roots'.

Given are some difference between an underground stem and a root. Select the option that identifies the incorrect pair of differences.

Underground stem Root
(i) It is differentiated into nodes and internodes it is not differentiated in to nodes and internodes.
(ii) Scale leaves are present at the nodes. Scale leaves are absent in roots.
(iii) Axillary buds are present in the axil of scale leaves. Axillary buds are present at root tips.
(iv) Branches arise exogenously. Branches arise endogenously.
(v) Flowers and fruits absent Flowers and fruits are absent.
(vi) These usually perform the function of food storage. These usually perform the function of food storage.
botany root - external morphology morphology of the root root system in plants root

  1. (i), (ii), and (vi)

  2. (i), (ii), and (iii)

  3. (iii), (v), and (vi)

  4. (ii), (iii), (v), and (vi)

Show answer
Correct Option: C
Explanation:

In underground stem axillary buds are present at the axil of scale leaves, roots do not give rise to buds-therefore incorrect.Flowers and fruits may be present in some underground stem (example Commelina). However, fruits and flowers are absent in roots - therefore statement incorrect. Underground stem usually perform the function of food storage (example- ginger, potato), however roots are meant to be underground, their primary function being absorption of water and minerals, only in certain cases they store food(sweet potato, carrot).

So, the correct answer is '(iii), (v), and (vi)'

From which one of the following a drug is obtained from roots to cure mental disorders?

botany root - external morphology morphology of the root root system in plants root

  1. Nepenthes

  2. Marigold

  3. Rauwolfia

  4. Riccinus

Show answer
Correct Option: C
Explanation:

The roots of the plant Rauwolfia serpentina or sarpagandha is used to treat hypertension and mental disorders. The roots of the plant are dried to extract  the alkaloid resperine from the plant, which is used for medicinal purposes.

Reserpine, was used to treat high blood pressure and mental disorders, including schizophrenia.