Sample Lesson 1

Leaves

The leaves are a plant's means of intercepting light, obtaining and storing water and food, exchanging gases, and providing a site for photosynthesis (which is a process to make food - will be discussed later). Leaves are specially designed by God to allow food production to take place. Most leaves have broad, flat surfaces in order to collect sunlight (which is needed to make food). Leaves also have areas which let out the waste substances created by photosynthesis.

A leaf contains a whole vein system called venation. In this system there are long strips of vascular tissue called veins (see illustration below). Veins supply the leaf with water and minerals, and also move the food made inside the leaf to other parts of the plant. Most leaves contain a central vein called the midrib, which is an extension of the leaf stalk (also called the petiole). The veins that branch off of the midrib are called side veins. The petiole is a thin structure that joins the stem to the main body of the leaf. It contains the leaf trace, which is an area of vascular tissue that branches off the vascular tissue in the stem, to become a leaf's central vein and main supply of minerals.