Tag: stem - external morphology

Questions Related to stem - external morphology

In a hollow stem, what is most affected?

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Conduction of food

  2. Conduction of water

  3. Storage of food

  4. None of the above

Show answer
Correct Option: C
Explanation:
Hollow stem is characterized by the disintegration of pith leaving the central space empty which is otherwise occupied by pith. The disintegration of pith is caused by rapid elongation and radial expansion of growing stem. Translocation of organic nutrient and water is the function of phloem and xylem respectively and hence, the disintegration of pith does not affect these functions. Pith serves to store and transport the nutrient while the hollow stem contains water, storage of food is most affected in hollow stem. 
Thus, the correct answer is option C.

Two types of plant organs are:

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. photosynthetic, non-photosynthetic

  2. vegetative and reproductive

  3. nutritive and non-nutritive

  4. organized, non-organized

Show answer
Correct Option: B
Explanation:

The plant organs are classified into vegetative structures that include leaf, root, stem etc and reproductive structures like the flower, fruits and seeds 

So, the correct answer is 'vegetative and reproductive'

According to apical cell theory, there is a single apical cell with three cutting faces in the shoot apex. This theory is applicable only some higher algae, bryophytes and pteridophytes and is not applicable to gymnosperms and angiosperms This theory was given by

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. C. Nageli

  2. Hanstein

  3. Schmidt

  4. Clowes

Show answer
Correct Option: A
Explanation:

Apical cell theory by Nageli in 1858, stated that in large number of cryptogams single solitary cell has been found to form the growing point and it was supposed that similar condition exists in higher plants too. The presence of complex growing apices in higher plants cannot be explained by this theory. 
Thus, the correct answer is option A.

The leaf less stem of onion which is produced to bear flower is called as

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Thalamus

  2. Scape

  3. Torus

  4. Pedicel

Show answer
Correct Option: B
Explanation:

Scape is the stalk of the stem that attaches the flower to its inflorescence. Onion plants produce a leafless flowering stem which exhibits scape. These have 2-4 leaves that are circular and hollow in cross-section, easily flattened when young. Whereas Torus is the thickened part of the stem from which flower grows. The older name of the torus is thalamus. Pedicel is short flower stalk that attaches the flower to inflorescence.
Thus, the correct answer is option B.

Interfascicular cambium arises from _______.

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Cortical cells

  2. Medullary rays

  3. Pericycle

  4. Endodermis

Show answer
Correct Option: A

Function of stem is

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Bear leaves and branches

  2. Conduction of water & minerals

  3. Conduction and storage of food

  4. All of the above

Show answer
Correct Option: D
Explanation:

The main functions of stems are as follows,

  • The stems bears branches and leaves and also gives place from where flowers and fruits grow.
  • Conduction of fluids and minerals between the roots and the shoots in the xylem and phloem.
  • Storage of food.
  • Stems have meristems that generate new living tissue.
    Thus, the correct answer is option D.

In which of the following are excurrent stem found?

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Cycas

  2. Pinus

  3. Mango

  4. Wheat

Show answer
Correct Option: B
Explanation:


  • An excurrent stem is the type of stem in which the main stem grows indefinitely. The side branch grows in an acropetal manner. The tree takes a pyramidal form due to development of racemose branching. This type of branching is mostly seen in pinus. This type of branching is mostly seen because the apical meristem has the dominance on the lateral ones which leads to an increase in the height of the plant.
  • Hence in Pinus excurrent stem is found.
  • So, the correct answer is  'Pinus'.

Bamboo, grass and mint stem elongate by the activity of 

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Primary meristem

  2. Secondary meristem

  3. Intercalary meristems

  4. Apical meristems

Show answer
Correct Option: C
Explanation:

Bamboo, grass and mint stem elongate by the activity of Intercalary meristems. Intercalary meristem at base of leaves or nodes of grasses is responsible for primary growth. Meristems are classified by their location as apical located at root and shoot tips, lateral in the vascular and cork cambia, and intercalary at internodes, or stem regions between the places at which leaves attach and leaf bases. Intercalary meristem cells possess the ability to divide and produce new cells, as do apical and lateral meristems. They differ, however, in being situated between regions of mature tissue, such as at the base of grass leaves, which are themselves located on mature stem tissue.
Thus, the correct answer is option C.

The basic difference between stem and root is that

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Stem is endarch

  2. Stem is exarch

  3. Stem is mesarch

  4. Stem is polyarch

Show answer
Correct Option: A
Explanation:
In endarch vascular bundle metaxylem lies towards the outer side and protoxylem towards the inner side.
In exarch vascular bundle protoxylem lies towards the outerside and metaxylem towards the centre.
Both dicot and monocot stem has endarch type of vascular bundle and dicot and monocot root have exarch type of vascular bundle.

Elongated reproductive apex is found in _____________.

botany stem - external morphology morphology of the stem stem shoot system in plants

  1. Sagittaria

  2. Chrysanthemum

  3. Rose

  4. Mango

Show answer
Correct Option: A