Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

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

Silica incrustation is found on the leaf surface in

  1. Mango

  2. Grasses

  3. Castor

  4. Oleander
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Plastochron is

  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
Reveal answer Fill a bubble to check yourself
A Correct answer
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'
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

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

  1. Transport of water and minerals

  2. Mechanical support

  3. Transport of organic food material

  4. All of these
Reveal answer Fill a bubble to check yourself
D Correct answer
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 ".

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

Period between initiation of two successive leaves or nodes is

  1. Plastochron

  2. Diurnal cyclicity

  3. Internode

  4. Allelopathy
Reveal answer Fill a bubble to check yourself
A Correct answer
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'
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

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

  1. Cystoliths

  2. Raphides

  3. Sphaeraphides

  4. Otoliths
Reveal answer Fill a bubble to check yourself
A Correct answer
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'.
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

Which one of the following statements is not correct?

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

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

  1. Leaf base

  2. Leaf buttress

  3. Node

  4. Plastochron
Reveal answer Fill a bubble to check yourself
A Correct answer
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'
    Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

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

    1. Nerium

    2. Eucalyptus

    3. Both A and B

    4. None of the above
    Reveal answer Fill a bubble to check yourself
    C Correct answer
    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.
    Multiple choice botany leaf - external morphology morphology of leaf structure of a leaf the leaf

    In a unifacial leaf, the stomata are present in

    1. Lower epidermis

    2. Upper epidermis

    3. Both of (A) and (B)

    4. Petiole
    Reveal answer Fill a bubble to check yourself
    C Correct answer
    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.

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

    In a floating leaved plants, stomata occur on

    1. Lower surface

    2. Upper surface

    3. Both of (A) and (B)

    4. Absent
    Reveal answer Fill a bubble to check yourself
    B Correct answer
    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.