Tag: internal structure of leaf (dicot and monocot)

Questions Related to internal structure of leaf (dicot and monocot)

In a dorsiventral leaf, the location of xylem and phloem is

  1. Abaxial and adaxial respectively

  2. Adaxial and abaxial respectively

  3. Both are abaxial

  4. Both are adaxial


Correct Option: B
Explanation:

in dorsiventral or dicot leaf, midirib or main vein represents the vascular bundles. In this, xylem is present towards upper epidermis and phloem present towards the lower epidermis. These are collateral, conjoint, closed the position of protoxylem and metaxylem is not specified clearly.

So, the correct answer is 'Adaxial and abaxial respectively'.

In dorsiventral leaves stomata occur

  1. More on upper palisade containing surface and less on spongy parenchyma containing lower surfac

  2. Fewer on upper surface and more on lower surface

  3. Equally on both

  4. None of the two surfaces


Correct Option: B
Explanation:

In dorsiventral leaves, less stomata are present in the upper epidermis and more stomata are present on the lower epidermis.

So, the correct option is ‘Fewer on upper surface and more on lower surface’.

Tetrarch bundles occur in

  1. Leaf of Cicer arietinum

  2. Leaf of Pisum sativum

  3. Root of Cicer arietinum

  4. Root of Zea mays


Correct Option: C
Explanation:

Stele with four vascular bundles is called tetrarch stele. it is generally found in dicotyledons. In the vascular bundles xylem and phloem are on different raidii. So the vascular bundles are called radial vascular bundles. In the xylem protoxylem is faced towards the pericycle and metaxylem is faced towards the medulla.  eg:Cicer arietinum  roots. 

So, the correct option is 'Roots of Cicer arietinum.