Tag: structure of a leaf

Questions Related to structure of a leaf

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.

    In a floating leaved plants, stomata occur on

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

    1. Lower surface

    2. Upper surface

    3. Both of (A) and (B)

    4. Absent

    Show answer
    Correct Option: B
    Explanation:

    Stoma (plural stomata) is a pore, found in the epidermis of leaves, stems and other organs that is used to control gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the opening.
    Dicotyledons usually have more stomata on the lower epidermis than the upper epidermis. Monocotyledons, on the other hand, usually have the same number of stomata on the two epidermis.
    In plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely.
    Thus, the correct answer is option B. 

    In a plant where the stomata are absent, some gaseous exchange still takes place through

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

    1. Aerenchyma

    2. Trichomes

    3. Pneumatophores

    4. Lenticels

    Show answer
    Correct Option: D
    Explanation:
    A lenticel is a porous tissue consisting of cells with large intercellular spaces in the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants.
    It functions as a pore, providing a pathway for the direct exchange of gases between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gases. 

    Which one of the following statement is correct?

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

    1. Offspring produced by the asexual reproduction are called clone

    2. Microscopic, motile asexual reproductive structures are called zoospores

    3. In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem

    4. Water hyacinth growing in the standing water drains oxygen from water that leads to the death of fishes

    Show answer
    Correct Option: C
    Explanation:

    Potato, banana, ginger grow from the axillary buds of nodes. Axiallary bud develops from the axillary part of leaf.  These buds can expand to form shoots which grow on to make a whole plant or fruits.

    So, the correct option is 'In potato, banana and ginger, the plantlets arise from the internodes present in the modified stem'.

    A leaf which possesses stomata exclusively its upper side is called as

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

    1. Oat type

    2. Mulberry type

    3. Lotus type

    4. Cactus type

    Show answer
    Correct Option: C
    Explanation:

    A leaf which possesses stomata exclusively its upper side is called as lotus type. Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or macrophytes. These plants require special adaptations for living submerged in water or at the water's surface. The most common adaptation is aerenchyma, but floating leaves and finely dissected leaves are also common.
    Thus, the correct answer is option C.

    Ochreate stipules occur in leafy vegetable

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

    1. Amaranthus

    2. Mentha

    3. Platanus

    4. Rumex

    Show answer
    Correct Option: D
    Explanation:

    There are different types of stipules present in plants such as lateral, ventral, scaly, intrapetiolar, interpetiolar, ochreate, spinous, tendrillar. In ochreate, the stipules are in the form of a tubular sheath around the internode. These are seen in leafy vegetables like Rumex and Polygonum. Foliaceous stipules occur in Lathyrus aphaca. Tendrillar stipules occur in Smilax. Thus, the correct answer is 'Rumex.

    In Nelumbium, Victoria, Tropaeolum the leaf blade is

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

    1. Peltate

    2. Centric

    3. Unifacial

    4. Ligulate

    Show answer
    Correct Option: A
    Explanation:

    In peltate leaf, the leaf blades are deeply lobed. In this, the petiole is attached to the middle of the adaxial side of the leaf. Examples of leaves having peltate leaf blade include Nelumbium, Victoria, Tropaeolum. In this, the petiole is attached to the surface of lamina. Thus, the correct answer is 'Peltate.'