Tag: evs

Quizzes (439) Questions (4580)

Questions Related to evs

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Root cap regenerated/dead torn cells of root cap are replaced by the activity of

  1. Plerome

  2. Dermatogen

  3. Calyptrogen

  4. Periblem
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Calyptrogen is the formative tissue found in the growing point of a root, giving rise to the root cap. Calyptrogen, as a rule, is characteristic of monocotyledonous plants. In most dicotyledonous plants, instead of calyptrogen, there is a tissue that also gives rise to the root’s absorbent external piliferous layer; this tissue is called dermatocalyptrogen.
The correct option is 'Calyptrogen'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

In the transverse section of a dicot root.

  1. The protoxylem vessels are present towards the periphery and metaxylem vessels are present towards the centre

  2. The protoxylem vessels are present towards the centre and metaxylem vessels are present towards the periphery

  3. Protoxylem is completely surrounded by the metaxylem vessels

  4. Metaxylem is completely surrounded by protoxylem
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In dicot roots, the xylem arrangement is exarch, meaning the protoxylem is located towards the periphery and the metaxylem is towards the center.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

In which of the following organs, growth is subapical?

  1. Shoot

  2. Petiole

  3. Root

  4. Pedicel
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Roots grow in length only from the ends. The tip of the root is covered by a root cap, which gives protection to the growing tip as it makes its way through the soil. The root has a subapical region, which is divided into three zones. They are, the zone of cell division, the zone of elongation and the zone of cell maturation. The subapical region carries out the growth of the roots.

 Hence, the correct answer is option C.
Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Root region with thin-walled, small cells having sense cytoplasm is

  1. Region of cell elongation

  2. Maturation region

  3. Proximal to cell elongation zone.

  4. Distal to cell elongation zone
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The protoplasm of the cell is surrounded by a primary cell wall which is laid down as the cell begins to grow. It is thin and composed of cellulose, hemicellulose and pectic substances. Once growth has ceased a secondary cell wall may form inside the primary cell wall.

So, the correct option is 'Region of cell elongation'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Main component of middle lamella is?

  1. Mg pectate

  2. Calcium pectate

  3. Calcium carbonate

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

The middle lamella is a pectin layer which cements the cell walls of two adjoining plant cells together. It is the first formed layer which is deposited at the time of cytokinesis. The cell plate that is formed during cell division itself develops into middle lamella or lamellum. In plants, the pectins form a unified and continuous layer between adjacent cells. Frequently, it is difficult to distinguish the middle lamella from the primary wall, especially in cells that develop thick secondary walls. The middle lamella is made up of calcium and magnesium pectates.

So the correct option is 'Mg pectate'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Consider the following statements.
(a) In a dicot root, the vascular bundles are collateral and endarch.
(b) The inner most layer of cortex in a dicot root is endodermis.
(c) In a dicot root, the phloem masses are separated from the xylem by conjunctive tissue. 
Of the above given statements

  1. (a) is true; but (b) and (c) are false

  2. (b) is true; but (a) and (c) are false

  3. (a) is false; but (b) and (c) are true

  4. (c) is false ; but (a) and (b) are true

  5. (c) is true; but (a) and (b) are false
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Dicot root shows radial vascular bundles, i.e., vascular bundles arranged in a ring. In this type of vascular bundle, the xylem and phloem are situated at different radii. Xylem is of exarch type, i.e., protoxylem is away from centre and metaxylem is towards centre. Hence, statement (a) is wrong.
The innermost layer of cortex in a dicot root is endodermis. It completely surrounds the stele. It consists of single layer of barrel shaped cells which lack intercellular spaces. Hence, statement (b) is correct. 
In a dicot root, the phloem masses are separated from the xylem by conjunctive tissues. Later, vascular cambium forms from this conjunctive tissue. Hence, statement (c) is correct. 
Thus, the correct answer is '(a) is false; but (b) and (c) are true'.

Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Passage cells are thin walled cells found in ____________________.

  1. Phloem elements to serve as entry points

  2. Testa of seeds for emergence of embryonal axis

  3. Central area of style for passage of pollen tube

  4. Endodermis of roots to facilitate rapid transport of water from cortex to pericycle
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Passage cells are thin walled cells present opposite to xylem patches in the endodermis of the root. They are endodermal cells.They are also called transfusion cells. They help in water transport from cortex to pericycle. 
So the correct answer is 'Endodermis of roots to facilitate rapid transport of water from cortex to pericycle'
Multiple choice evs identifying the plants absorption of water from the soil root system the root system

Velamen tissue is found in ................

  1. Mesophytes

  2. Epiphytes

  3. Hydrophytes

  4. Xerophytes
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A typical aerial root of epiphytes consists of a specialised outer epidermis of several cell layers, called as the velamen. When mature, these cells are dead and filled with air. The velamen acts as a site for temporary water storage.
So, the correct answer is 'Epiphytes'