Tag: the leaf

Leaves are exogenous (develop away from the plant body) in origin and develops from the swollen leaf primordium of the growing apex.

• Guard cells are specialized epidermal cells present on the surface of leaves and stems of plants that control the gaseous exchange in plants.
• The guard cells form stomatal pores through which gaseous exchange and transpiration take place.
• In monocots, the guard cells are dumbbell shape.
• In dicots, they are kidney or bean shaped.
• So, the correct answer is 'Beans'.

Stomata are the openings surrounded by the guard cells that are specialized epidermal cells. These are present on the underside of the leaves and perform the functions of exchange of gases and transpiration.

Broad part of leaf is lamina. The lamina is the expanded portion of a leaf and it is specialized for photosynthesis. For this purpose, a leaf is typically flat and thin, to expose the chlorenchyma to light over a broad area and to allow light to penetrate fully into the tissues. 
Thus, the correct answer is option C.

Exogenous, flattened, green, lateral appendages arising from nodes of the stem or branches in acropetal succession are called as leaves. Leaves arise from shoot apical meristem and bear buds in their axils and help in assimilation of food, exchange of gases and transpiration. So, leaf is a lateral outgrowth of stem.  

• During fertilization of Funaria, the ventral canal cell and the neck canal cells of the archegonium dis­integrate forming a mucilaginous substance. This mucilaginous substance absorbs water accu­mulated as rain or dew water, then swells up and the resultant pressure breaks apart the terminal cover cell. Now sugar containing mucilaginous substances ooze out through the opening of the archegonial neck.
• The liberated antherozoids are now attrac­ted chemotactically towards the archegonia. Large numbers of antherozoids enter the neck, but only one of them fuses with the egg nucleus to form the diploid zygote.
  
• Hence In Funaria, archegonia attract antherozoids by 'Sucrose / Sugar '.
• So, the correct answer is 'Sucrose / Sugar '.

• Node: The leaves arise in the regions of the plant known as the plant nodes and are therefore the point of attachment of the leaves. 
• The region of the plant between two nodes is known as the internode.
•  The angle between the upper surface of the leaf and the stem from which it arises is known as the axil. 
• The petiole is the stalk which attaches the leaf to the stem. 

leaf is a green outgrowth of a stem. It performs photosynthesis and provides food to the rest of the plant body. There are different types of leaves found due to climate, water availability, etc. A leaf consists of lamina and petiole, leaves can be monocot or dicot. It contains stomate which helps in gaseous exchange.