Vegetative Structure of a leaf...best answer 10 pts....help me pls.?

Question

What is the Vegetative Structure of a Leaf...

Answer 1

Blade. The broad, flat, expanded portion of the leaf, in which most of the photosynthetic activity occurs, is termed the blade.

Petiole. The stalk that supports the blade and connects it to the stem.

Stipules. A pair of small, often inconspicuous appendages that arise at the base of the petiole. Stipules do not occur in all plants and, more often than not, their function is not apparent.

Leaf Axil. The angle formed between the petiole of the leaf and the stem.

Axillary Bud. A small bud located in the leaf axil on the upper side of the petiole where it connects to the stem. Axillary buds usually develop into the branches of the plant body.

Answer 2

The typical plant leaf is made up of many tissues and cells. The top layer is called the upper epidermis and is covered by a waxy cuticle, which prevents moisture loss. On the underside of a leaf, the lower epidermis includes stomata, which are openings to the inner leaf that allow air to enter. The stomata are each opened and closed by a pair of guard cells, which control the amount of CO2 (used in photosynthesis), and moisture let into the leaf (Campbell 1996). Below the upper epidermis are elongated cells including chloroplasts, which contain chlorophyll and other photosynthetic pigments. These cells form the palisade layer. Between the palisade tissue and the lower epidermis lies tissue made up of non-uniform cells separated by air spaces. This tissue is called spongy mesophyll where the cells absorb carbon dioxide and expel oxygen into the air spaces in the processes of photosynthesis and respiration. Although the structure of leaves contain these basic components, all leaves are not the same which allows them to respond differently to like circumstances such as exposure to identical levels of light.