Tag: internal structure of leaf (dicot and monocot)

A.Isobilateral leaves – Mesophyll is undifferentiated, contains spongy parenchyma only.

B.Dorsiventral mesophytic leaves – Mesophyll is differentiated into upper palisade parenchyma and lower spongy parenchyma.

C.Dorsiventral xerophytic leaves – Mesophyll is differentiated into upper and lower palisade parenchyma and middle spongy parenchyma.

D.Vertical leaves - Mesophyll is differentiated into upper and lower palisade parenchyma and middle spongy parenchyma.

So, the correct option is ‘isobilateral leaves’.

In isobilateral leaves or monocot leaves, stomata are present on both upper or adaxial epidermis as well as lower epidermis or abaxial epidermis.

So, the correct option is ‘Both upper and lower surfaces’.

Dicot leaf differs from monocot leaf anatomically in terms of presence of more number of stomata in the lower epidermis, presence of differentiated mesophyll,  and vascular bundle.

Leaf, in which both surfaces are similar in appearance are called isobilateral leaves. These are found in monocotyledons. It is due to the presence of spongy parenchyma.

So, the correct option is ‘Similarly two green surfaces’.    

• Leaves have a layer of waxy cuticle on their surface as it helps in preventing water loss due to excess transpiration. The leaves may also have hair on the lower surface which act as trichomes and protect the surface of the leaves.
• The epidermis of the leaves has minute pores called stomata through which gaseous exchange takes place.
• Endodermis and Casparian strips are present in the roots of the plants.

Bulliform cells or the motor cells are the modified epidermal cells present on the upper surface or the adaxial surface of the monocot leaf (the grasses). They are colourless, large-sized and vacuolated cells. They regulate the rolling of leaves to prevent the loss of water. When water is adequately present, they become turgid and keep the leaf open and exposed. When there is scarcity of water, the become flaccid and roll-up the leaf to prevent the loss of water.

Palisade parenchyma cells are plant cells found within the mesophyll in leaves, right below the upper epidermis and cuticle. They are vertically elongated, a different shape from spongy mesophyll cells beneath them in the leaf. Their chloroplasts absorb a major portion of the light energy used by the leaf. 

Palisade cells are plant cells found within the mesophyll in leaves, right below the upper epidermis and cuticle. They are vertically elongated, a different shape from spongy mesophyll cells beneath them in the leaf. Their chloroplasts absorb a major portion of the light energy used by the leaf. Palisade cells occur in dicotyledonous plants and also in the net-veined monocots. The spongy mesophyll are usually ball-shaped with large intercellular spaces but usually contains fewer chloroplasts than the palisade cells. They are also present in dicot leaf. 

Stomata is a pore, found in the epidermis of leaves, 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. Stomata are present in the sporophyte generation of all land plant groups except liverworts. 

Dorsiventral leaf i.e. Mesophyll is the ground tissue and it occurs between the two epidermal layers. It is heavily composed of chlorenchyma cells. The mesophyll is differentiated into two regions an upper palisade parenchyma and lower spongy parenchyma. Palisade parenchyma is again composed of two or three layers of elongated and compactly arranged chlorenchyma cells.

Also, the isobilateral leaf has undifferentiated mesophyll.

Therefore, the correct answer is option B.