Tag: botany

Quizzes (264) Questions (5276)

Questions Related to botany

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Which of the following statements are the functions of a medullary ray in plants?

  1. Storage of food

  2. Secondary growth

  3. Both of the above

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Medullary ray is a band of parenchyma in the secondary xylem extending into the secondary phloem of the stems of certain vascular plants, formed by the cambium and helps for the storage of food and conduction of nutrients. it helps in the gaseous exchange through the intercellular spaces.

So, the correct answer is 'Storage of food'.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Lateral roots are endogenous in origin as they develop from

  1. Cortex

  2. Endodermis

  3. Pericycle

  4. Vascular strands
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The roots that arise horizontally from the primary roots which provide anchorage to the plants and fixes it into the soil. 
  • These roots help in the uptake of water and nutrients from the soil which is required for the growth and development of the plants.
  • They are endogenous in nature as it is developed from the cells of the pericycle which become meristematic and undergoes periclinal (parallel to the surface of a part) and anticlinal (right angles to the surface) division.
  • So, the correct answer is 'Pericycle'.
Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Passage cell is always  located opposite to 

  1. Protoxylem elements

  2. Metaxylem elements

  3. Phloem

  4. Pith
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • Passage cells are also known as transfusion cells.
  • They are thin-walled cells which lack suberin and are found in the endodermis (is the central innermost layer of the cortex) of vascular plants (plants which consist of vascular tissues i.e, xylem and phloem).
  • They are located opposite the protoxylem strands or elements.
  • They are found in the endodermis of dicots.
  • So, the correct answer is 'Protoxylem elements'.
Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Parenchyma cells filling the space between dermal and vascular tissues form ________.

  1. Ground tissue

  2. Epidermal tissue

  3. Medulla

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

The tissues present in a plant which are dermal nor vascular are called ground tissues.

  • The ground tissues consist of the following:-
1) Parenchyma cells- are the cells which have a thin primary wall, they are usually present in the pericycle, pith, and medullary rays of primary stem and root.
2) Collenchyma cells - have thin primary walls with secondary thickening at corners.
  • They provide mechanical and structural support in regions of new growth in plants.
3) Sclerenchyma cells - have a thick and lignified secondary walls and are dead in nature. 
  • They provide structural support to plants.
So, the correct answer is 'Ground tissue'.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Ground tissue includes

  1. All tissues internal to endodermis

  2. All tissues external to endodermis

  3. All tissues except epidermis and vascular bundles

  4. Epidermis and cortex
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
The ground tissue of plants includes all tissues except dermal or vascular tissues. It is divided into three classes based on the nature of the cell walls. Parenchyma cells have thin primary walls and remain alive on maturation. Collenchyma cells have thin walls with some areas having secondary thickening. It provides additional structural support in regions of new growth. Sclerenchyma cells have thick secondary walls and is often dead. It provides the main structural support to a plant
So, the correct answer is 'All tissues except epidermis and vascular bundles'
Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

In general, the cells of cortex lack

  1. Chlorophyll

  2. Nucleus

  3. Reserve food

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

Cortex is the ground tissue present between epidermis and endodermis. It is mostly composed of parenchymatous cells. Parenchymatous cells are thin walled polyhedral, isodiametric living cells with sufficient cytoplasm, one or more nuclei and nucleolus. They serve to store food. Chlorophyll is present in chlorenchyma which are specialized to perform photosynthesis and are present in leaves. Thus, the correct answer is option A.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Passage cells are characteristic of

  1. Primary endodermis of dicots

  2. Secondary endodermis of monocots

  3. Bundle sheath of leaves

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Passage cells forms the endodermis of older roots of monocots. They are thin walled and have casparian strips, unlike the other cells that becomes suberized and waterproof. Passage cells function to allow transfer of solutes into the stele, in order to eventually reach the transpiration system.

Thus, the correct answer is option B.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

In roots, the pericycle give rise to

  1. Lateral roots and cork cambium

  2. Cortex and pith

  3. Xylem and phloem

  4. Epidermis and vascular bundles
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Pericycle is a primary tissue of plant roots and is the site for the initiation of lateral roots and two secondary meristems, the vascular cambium and cork cambium (phellogen). 

The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Although it is composed of non-vascular parenchyma cells, it is still considered part of the vascular cylinder, because it arises from the procambium as do the vascular tissues it surrounds.
In dicots, it also has the capacity to produce lateral roots. Branch roots arise from this primary meristem tissue. In plants undergoing secondary growth, the pericycle contributes to the vascular cambium often diverging into a cork cambium
So, the correct answer is 'Lateral roots and cork cambium'

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

The layers of cells lying between endodermis and vascular bundle is

  1. Cortex

  2. Pith

  3. Pericycle

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

The layers of cells lying between endodermis and vascular bundle is pericycle. The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Although it is composed of non-vascular parenchyma cells, it is still considered part of the vascular cylinder, because it arises from the procambium as do the vascular tissues it surrounds.

Multiple choice botany plant tissue system ground tissue system ground tissues tissue systems

Which is not correct about heartwood?

  1. It is formed of living cells.

  2. It contains resins, tannin and other organic contents.

  3. It is of dark colour.

  4. It lies in the centre region.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heartwood is also called as 'duramen'. It is dead, central wood of trees. Its cells usually contain tannins or other substances that make it dark in colour and sometimes aromatic. Heartwood is mechanically strong, resistant to decay and less easily penetrated by wood-preservative chemicals than other types of wood.