Tag: internal structure of leaf (dicot and monocot)

Leaves, in which both surfaces are differentiated are called dorsiventral leaves. In these leaves, palisade parenchyma is present towards the upper epidermis and spongy parenchyma is present towards the lower epidermis. Because of this reason, in dorsiventral leaves, the upper side is dark green in colour and lower side is light green in colour.

So, the correct answer is ‘Upper surface is dark green as compared to the lower surface’.

The parenchyma with loosely arranged cells, present in the mesophyll of leaves is called spongy parenchyma.

So, the correct option is ‘Loosely arranged’

In xerophytic leaves, mesophyll is differentiated into palisade and spongy parenchyma. In these leaves, palisade parenchyma is present on both sides. i.e towards upper epidermis and lower epidermis. In the palisade parenchyma cells are cylindrical in shape contains more number of chloroplasts. In spongy parenchyma, cells are oval in shape, loosely arranged, with less number of chloroplasts. 

The region present between the upper and lower epidermis of leaves is called mesophyll. It is differentiated into upper palisade and lower spongy parenchyma in dicot leaves or dorsiventral leaves, whereas in monocot leaves or isobilateral leaves, it is undifferentiated and it shows spongy parenchyma.

So, the correct option is ‘All dorsiventral leaves’.

a-bulliform cells                3) Grasses

b)Pericycle                         1) Initiation of lateral roots

c)Endarch xylem                5)stem

d)Exarch xylem                  2)Root

e)Bundle sheath cells       3)Grasses

So, the correct option is ‘a-3, b-1, c-5, d-2, e-4

Transpiration is the evaporative loss of water by plants. It occurs mainly through the stomata in the leaves. Usually the lower surface of a dorsiventral (often dicotyledonous) leaf has a greater number of stomata while in an isobilateral(often monocotyledonous) leaf. There are almost equal number of stomata on both surfaces.

Dorsiventral leaves orient themselves at an angle to the main axis and perpendicular to the direction of sunlight. Most dicots have dorsi-ventral leaves that are net-veined, including most trees, bushes, garden plants and wildflowers. Mesophyll is the ground tissue between the upper and lower epidermis. In dorsiventral leaf, it is differentiated into palisade parenchyma and spongy parenchyma. Palisade parenchyma lies towards the upper epidermis and consists of one, two or three layers of elongated cells, densely packed with no intercellular spaces and contains chloroplast

In the vascular bundles of dicot leaves, xylem and phloem are present on same radius and also present side by side. So they are called collateral and conjoint. Cambium is absent between xylem and phloem. So, It is called closed vascular bundle.

A dorsiventral organ is one that has two surfaces differing from each other in appearance and structure, as an ordinary leaf. This term has also been used as a synonym for dorsoventral organs, those that extend from a dorsal to a ventral surface. Dorsi-ventral leaves which usually orient at an angle to the main axis and held perpendicular to the direction of sunlight. An isobilateral leaf is usually vertically oriented to expose both surfaces to the sun. The leaves hang vertically to expose one face directly to the drying sun, then the other face. They have equal numbers of stomata in matching quantities and surface qualities of cuticle on both faces of the leaf. Epistomatic leaf has stomata on the upper surface only. Hypostomatic leaf having stomata on the underneath, i.e., foliar abaxial surface.