Tag: morphology of leaf

Questions Related to morphology of leaf

Leaf base is sheathing in

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Wheat

  2. Maize

  3. Grass

  4. All of the above

Show answer
Correct Option: D
Explanation:

In grasses and many monocots, the leaf base (petiole) is broad and surrounds the stem as an envelope. Such a leaf base is known as sheathing leaf base. In grasses such as wheat, maize and grass, the sheathing leaf base protects the intercalary meristem. Hence, the plants belonging to family Poaceae have sheathing leaf base.

So, the correct answer is 'All of the above'.

Silica incrustation is found on the leaf surface in

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Mango

  2. Grasses

  3. Castor

  4. Oleander

Show answer
Correct Option: B
Explanation:
  • Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
  • Silicon is found on the leaf surface in the form of spines and other sharp bodies which are known as phytoliths.
  • It makes the grasses abrasive and foliage indigestible to organisms feeding on them (herbivores).
  • Silica incrustation is the deposition of silicon on the leaf surface, it is a defence mechanism found in closely related species of grasses which makes its leaves abrasive.
  • So, the correct answer is 'Grasses'.

Plastochron is

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Period between two successive leaf primordia

  2. Distance between two successive leaf primordia

  3. Region of origin of root branch

  4. Region of origin of stem branch

Show answer
Correct Option: A
Explanation:
  • Plastochron is the time interval between the two successive events during the growth of plants.
  • As in the case, when the shoot tip of a plant grows new leaves are produced at regular time intervals.
  • This time interval between the beginning of leaf growth at 2 consecutive nodes in a growing shoot apex by keeping the temperature constant is called Plastochron.
  • So, the correct answer is 'Period between two successive leaf primordia'

Which of the following represents the functions of veins in the leaves?

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Transport of water and minerals

  2. Mechanical support

  3. Transport of organic food material

  4. All of these

Show answer
Correct Option: D
Explanation:

Veins have vascular tissues xylem and phloem. Xylem fulfills the requirement of water of the leaves. Phloem transport food energy to the leaves. They also provide support for the leaf.

So, the correct answer is "  all of these ".

Period between initiation of two successive leaves or nodes is

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Plastochron

  2. Diurnal cyclicity

  3. Internode

  4. Allelopathy

Show answer
Correct Option: A
Explanation:
  • When the shoot tip of a plant grows new leaves which are produced at regular time intervals.
  • This time interval between the beginning leaf growth at 2 consecutive nodes in a growing shoot apex by keeping the temperature constant is called plastochron.
  • So, the correct answer is 'Plastochron'

Crystals of calcium carbonate forming bunches in the epidermal cells of certain leaves are

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Cystoliths

  2. Raphides

  3. Sphaeraphides

  4. Otoliths

Show answer
Correct Option: A
Explanation:
  • Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
  • Cystoliths refers to the deposition of calcium carbonate in the epidermal cells of leaves of the plants belonging to the genus Acanthaceae and Urticaceae (stinging nettles).
  • So, the correct answer is 'Cystoliths'.

Which one of the following statements is not correct?

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. In Capparis, aphylla, stipules become modified into spines

  2. In Nerium, sunken stomata are present on both upper and lower epidermis and lower epidermis

  3. In Asparagus roots store water

  4. In the needle of Pinus roxburghii, sclerenchymatous hypodermis is present

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Correct Option: A

Protruded part of meristem flank bearing leaf primordium is called ________.

botany leaf - external morphology morphology of leaf structure of a leaf the leaf

  1. Leaf base

  2. Leaf buttress

  3. Node

  4. Plastochron

Show answer
Correct Option: A
Explanation:
  • A leaf base is also known as hyphopodium, it is the lowermost part of the leaf which is slightly expanded region where the leaf get attached to the stem.
  • It is indistinct in most of the plants which act as a cushion for the leaves.
  • The vegetative shoot apex consists of two regions i.e, summit and flank.
  1. Summit-  The rate of division is slow and it is located at the apex.
  2. Flank- The rate of division is very fast and it lies behind the summit.
    • Leaf primordium is formed on the flanks by the flank meristem.
    • So, the correct answer is 'Leaf base'

    In which plant palisade tissue is present on both sides of leaves?

    botany leaf - external morphology morphology of leaf structure of a leaf the leaf

    1. Nerium

    2. Eucalyptus

    3. Both A and B

    4. None of the above

    Show answer
    Correct Option: C
    Explanation:
    Leaves capable of being divided into symmetrical halves along two different planes is called as isobillateral.
    Eucalyptus and Nerium oleander are both isobilateral. So, they have palisade on both sides and the leaves.

    In a unifacial leaf, the stomata are present in

    botany leaf - external morphology morphology of leaf structure of a leaf the leaf

    1. Lower epidermis

    2. Upper epidermis

    3. Both of (A) and (B)

    4. Petiole

    Show answer
    Correct Option: C
    Explanation:

    In an unifacial leaf, the stomata are present in lower and upper epidermis. Unifacial leaf is also called as isobilateral or amphistomatic. Unifacial leaf is a leaf that develops from one side of the leaf primordium only and in consequence has only an encircling adaxial or abaxial epidermis (may be secondarily flattened and appear dorsiventral).
    Thus, the correct answer is option C.