Tag: zones of the root

Quizzes (0) Questions (16)

Questions Related to zones of the root

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Choose the incorrect statement.

  1. Epiphytic roots and Vanda has well developed root cap and root hair

  2. Tinospora and Trapa possess assimilatory roots

  3. Cuscuta is a parasitic plant

  4. Saccharum and Zea mays possess still toots
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Epiphytic roots (like those in Vanda) are hygroscopic and lack root hairs and a true root cap; instead, they possess a velamen tissue for moisture absorption. The other statements correctly describe Tinospora/Trapa, Cuscuta, and Saccharum/Zea mays.

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Hairy root disease of dicot plants is caused by

  1. Agrobacterium tumefaciens

  2. Agrobacterium rhizogene

  3. Bacillus thuringiensis

  4. Meloidogyne incognita
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • A soil bacterium Agrobacterium rhizogenes causes “hairy root” disease in some dicotyledonous plants(For example, capsicum species).
  • A bacterial Ri (root inducing) plasmid integrates its transfer-DNA (T-DNA) into the plant genome (DNA). As a result, rapidly growing and intensely branched (hairy) adventitious roots are developed.
  • Hence Hairy root disease of dicot plants is caused by Agrobacterium rhizogene.
  • So, the correct answer is 'Agrobacterium rhizogene'.
Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Clowes observed a central cup like region of passive cells in the root tip of Zea mays which lies in between?

  1. Root cap and active root meristem

  2. Protoderm and procambium

  3. Cork cambium and quiescent centre

  4. Quiescent centre and calyptrogen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The quiescent centre is a region of inactive or slowly dividing cells located between the root cap (calyptra) and the active root apical meristem. It serves as a reservoir of cells to replace damaged meristematic cells.

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Root cap is absent in

  1. Hydrophytes

  2. Lithophytes

  3. Xerophytes

  4. Mesophytes
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Root caps are present in terrestrial plants to protect the root tip from breaking away as they grow deeper through the layers of the soil. However,the roots of hydropytes that are floating or submerged do not have to grow through the abrasive layers of soil, as the roots are floating in water or the soil is soft and water logged.

So, the correct answer is 'Hydrophytes'

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

How many divisions must occur in a cell of root tip to form 128 cells ?

  1. 128

  2. 127

  3. 64

  4. 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Root tip cells are somatic cells. Therefore, it will divide by mitotic division.
$1$ parent cell with form $2$ daughter cells. Then, we can calculate after $127$ divisions of cells it will form $128$ cells.
Therefore, the option (B) is correct.
Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Rearrange the following series as seen in the rest in vertical section and choose the correct option:
(a) Rest hair zone  (b) zone of meristem
(c) Rest cap zone   (d) zone of maturation
(e) zone of elongation

  1. c, b, e, a, d

  2. a, b, c, d, e

  3. d, e, a, c, b

  4. e, d, c, b, a
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The correct longitudinal sequence of root zones from the tip upwards is: Root cap zone (c), Zone of meristem (b), Zone of elongation (e), Root hair zone (a), and Zone of maturation (d).

Multiple choice botany root - external morphology zones of the root morphology of root root system in plants

Rearrange the following zones as seen in the root in vertical section and choose the correct options.


A. Root hair zone  B. Zone of meristems
C. Root cap zone  D. Zone of maturation
E. Zone of elongation

  1. C, B, E, A, D

  2. A, B, C, D, E

  3. D, E, A, C, B

  4. E, D, C, B, A
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sequence of zones in a root from the tip upwards is: Root cap (C), Meristematic zone (B), Elongation zone (E), Root hair zone (A), and Maturation zone (D).