Tag: the root system

Questions Related to the root system

A plant with epidermis specialised to absorb mositure from air is?

evs identifying the plants absorption of water from the soil root system the root system

  1. Avicennia

  2. Vanda

  3. Rhizophora

  4. Jussiaea

Show answer
Correct Option: B
Explanation:

A plant with epidermis specialized to absorb moisture from the air is Vanda because vanda is an epiphyte with modified epidermis called velamen. As it stays on the host plant branches, its roots hang in the air absorbing moisture from the atmosphere.

So, the correct option is 'Vanda'.

Lateral roots arise from primordia developed by division of

evs identifying the plants absorption of water from the soil root system the root system

  1. Pericycle cells in between two protoxylem points

  2. Pericycle cells opposite protoxylem points

  3. Endodermis cells in between two protoxylem points

  4. Endodermis opposite protoxylem points

Show answer
Correct Option: A
Explanation:

Lateral roots arise endogenously from other roots and increase the absorptive surface of the plant. Most lateral roots are initiated some distance basipetal to the apical meristem, differentiated cells must become reprogrammed to give rise to the initial divide and enlarge in very precise patterns to organize a new organ recognizable as a root. 

Root hair develop from

evs identifying the plants absorption of water from the soil root system the root system

  1. Zone of cell maturation

  2. Zone of cell elongation

  3. Zone of mature cells

  4. Zone of cell formation

Show answer
Correct Option: A
Explanation:
The region of maturation is located at the top of the root, or closest to the plant. The end of the root is known as the root cap. A plant cell will begin in the region of cell division, and then travel to the region of elongation. In this zone, a cell will elongate and then travel to the zone of maturation. Root hair cells are outgrowths at a tip of the plant's roots. 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.

So, the correct answer is 'A'.

Cells of quiescent centre have lower concentration of

evs identifying the plants absorption of water from the soil root system the root system

  1. DNA

  2. Proteins

  3. RNA

  4. All of the above

Show answer
Correct Option: D
Explanation:
  • The quiescent centre is that part of the root-promeristems that contains the initials of epidermis, cortex and stele which divides less frequently and are present at the pole of cortex and stele.
  • In closed meristems, QC is hemispherical in shape whereas, in open meristem it is disc-shaped. 
  • The cells with QC have small dictyosomes, nuclei and nucleoli. 
  • 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 'All of the above'.

Root hairs are

evs identifying the plants absorption of water from the soil root system the root system

  1. Always unicellular

  2. Sometimes unicellular

  3. Sometimes multicellular

  4. Always multicellular

Show answer
Correct Option: A
Explanation:

The small, tubular, unicellular outgrowths formed from the root epidermal cells called root hairs.

So, the correct option is ‘Always unicellular’.

In case tunica, is multilayered which is likely to happen?

evs identifying the plants absorption of water from the soil root system the root system

  1. All layers take part in formation of multilayered epidermis

  2. All the layers produce cortex

  3. Outer most layer forms hypodermis, middle layer cortex and inner layer endodermis

  4. Only the outermost layer forms the epidermis

Show answer
Correct Option: D
Explanation:

When the tunica is multilayered, the condition is called multistratose tunica. The layers of tunica can be designated as L1, L2, L3 and so forth. The L1 or the outermost layer of the tunica would give rise to the epidermis and the rest of the layers would form the cortex and the vascular tissues, as seen in Datura.

Hence, the correct answer is 'Only the outermost layer forms the epidermis'.

Quiescent centre occurs in

evs identifying the plants absorption of water from the soil root system the root system

  1. Shoot apex

  2. Root apex

  3. Both A and B

  4. Meristematic tissue

Show answer
Correct Option: B
Explanation:
  • The root-promeristems of higher plants have a central part called the quiescent centre.
  • The cells here divide less frequently as they are inactive and are present at the pole of cortex and stele.
  • They may consist of four cells (minimum) or can go up to 600 cells which show very low mitotic activity.
  • In closed meristem, QC is hemispherical in shape whereas, in open meristem it is disc-shaped.
  • The QC is unusual in the centre of shoots.
So, the correct answer is 'Root apex'

Quiescent centre is region of root apex which is

evs identifying the plants absorption of water from the soil root system the root system

  1. Actively dividing

  2. Water absorption area

  3. Inactive cells

  4. Root hair area

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. 
  • 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 'Inactive cells'

Cells of quiescent centre are characterised by

evs identifying the plants absorption of water from the soil root system the root system

  1. Dense cytoplasm and prominent nuclei

  2. Light cytoplasm and small nuclei

  3. Dividing regularly to add to the corpus

  4. Dividing regularly to add to tunica

Show answer
Correct Option: B
Explanation:
  • The quiescent centre or QC is a part of the root-promeristems that contains the initials of epidermis, cortex and stele.
  • The cells here 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 'Light cytoplasm and small nuclei'.

Calyptrogen gives rise to

evs identifying the plants absorption of water from the soil root system the root system

  1. Root

  2. Root cap

  3. Plerome

  4. Periblem

Show answer
Correct Option: B
Explanation:
  • The root apical meristem gives rise to three primary meristems- procambium, ground meristem, protoderm and the root cap
  • Calyptrogen is a specialized internal meristematic cell derived from the root apical meristem
  • They divide internally to produce a protective cap-like structure at the root tip called the root cap
  • The root cap is also known as calyptra
So, the correct answer is 'Root cap'