Leaf has 2 main parts:

    1. Leaf Blade

It is the broad, flat surface of Leaf where Photosynthesis occurs. It is generally green in colour due to the presence of a pigment called 'Chlorophyll.' It has a 'mid-rib' or mid-vein in the center from where other smaller veins branch out to the edge.

      2. Stalk

This Stalk connects Leaf Blade to Stem. It has tiny tubes through which water and food are transported to and from the Leaf.

• The main function of the Leaf is to carry-out Photosynthesis which provides the plant with the food it needs to survive.
• 'Photosynthesis' is the process in which the Leaf takes-in Water (from roots), Carbon-di-oxide (from atmosphere) and Sunlight (happens only during day-time, when Sun is present) to prepare food for the plant.
• 'Respiration' is a process in which Plants, just like other Living Organisms take-in Oxygen from the Atmosphere and give-out Carbon-di-oxide. This happens during night-time.

Verified answer

• The leaf blade: It is also called the lamina. It's generally broad and flat. ...
• The petiole: It is the stalk-like structure which connects the leaf blade to the stem. The petiole has tiny tubes, that connect the veins on the leaf blade to the stem.
• A leaf (plural leaves) is the principal lateral appendage of the vascular plant stem,[1] usually borne above ground and specialized for photosynthesis. The leaves and stem together form the shoot.Leaves are collectively referred to as foliage, as in "autumn foliage".[3][4] In most leaves, the primary photosynthetic tissue, the palisade mesophyll, is located on the upper side of the blade or lamina of the leaf[1] but in some species, including the mature foliage of Eucalyptus,[5] palisade mesophyll is present on both sides and the leaves are said to be isobilateral. Most leaves are flattened and have distinct upper (adaxial) and lower (abaxial) surfaces that differ in color, hairiness, the number of stomata (pores that intake and output gases), the amount and structure of epicuticular wax and other features. Leaves are mostly green in color due to the presence of a compound called chlorophyll that is essential for photosynthesis as it absorbs light energy from the sun. A leaf with white patches or edges is called a variegated leaf.

1. The cycle of photosynthesis and respiration maintains the balance of oxygen and carbon dioxide. Photosynthesis produces the oxygen to replenish oxygen that is used up by living organisms during respiration. Carbon dioxide produced during respiration is one of the reactants plants need to perform photosynthesis.

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