Tag: structure of a leaf

A swollen leaf base is called as Pulvinus. This type of leaves are seen in Fabaceae family. The swelling results due to change in the turgor pressure. Night closure movement of legume leaves shows this pulvinar movement. The pulvinus protects the young axillary bud.

Pulvinus is a swollen leaf base. Pulvinate leaf base is found in leguminous plants. It is seen in mango leaves. It is seen in Fabaceae family. Example includes Trifolium pratense.

Compound leaves are of two types, namely pinnately compound leaves and palmately compound leaves. In palmately compound leaf, the leaflets are arranged at the tip of the petiole. It is further divided into 5 types depending upon the number of leaflets present at the tip of the petiole. In unifoliate, there is only one terminal leaflet is attached at the top of petiole. Example includes Citrus. In bifoliate, two leaflets are attached side by side at the terminal end of petiole. Example includes Balanites roxburghii. In trifoliate, three terminal leaflets are attached at the terminal end of petiole. Example includes Aegle marmelos. In quadrifoliate, four leaflets are attached to the tip of petiole. Example includes Paris quadrifolia. In multifoliate, five or more leaflets are present at the tip of petiole in the form of fingers of the palm. Example includes Bombax malabarica.

A ligule is a variously modified extension of the sheath lying at the base of the blade. While this vegetative part of the leaf blade of the family of grasses, is often a vertical membrane present as an outgrowth at the inner junction of the leaf sheath and blade, in heterosporus lycophytes, this is one of the enigmatic structures. The term which means a little tongue is an appendage that is found at the adaxial side of the leaves. Found in mostly Selaginellales and Isoeteles, the mature ligule shows four regions, sheath, glossopodium, main body and apex. The sheath is the base of the ligule which is composed of long tube shaped cells. The glossopodium is found just above the sheath as vaculoted cells.
Therefore, the correct option is A.

Leaves, in which stomata are present on the upper epidermis are called epistomatic leaves. In Nympheae, Nelumbo, Victoria, epistomatic leaves are present.

So, the correct option is ‘All of the above’.

The function of the stomata is to allow water vapor and gases to pass in and out of the leaf. The stomata are also responsible for the process of transpiration, the rate at which a plant loses water. Air enters the plant through the stomata. The air contains carbon dioxide which is used in the photosynthesis process. Then the transpiration and photosynthesis are the main functions of leaves.

Hydrophytes, in which root system is rooted in the soil and their leaves float on the surface of water. In these leaves, stomata are present on the upper epidermis or surface. Such leaves are called Epistomatous leaves. Eg:Nelumbo, Nympheae.

So, the correct option is ‘Upper surface’.

In the vascular bundles of leaves, xylem is situated towards the adaxial or upper epidermis side and phloem is situated towards the abaxial or lower epidermis side.

So, the correct option is ‘lower epidermis’.

The main function of leaf is photosynthesis. It produces food for the plant. It has a photosynthetic pigment chlorophyll which converts solar energy into chemical energy. The leaf is also involved in the transpiration process. The transpiration process helps in cooling of plant. The exchanges of gases takes place through stomata present on the leaves.