GRADE FIVE SCIENCE
Hello Boys and Girls, Have you had a full week? Has your school completed inter house sports? What part did you play or will you play? Exercise is very good for you. It helps you in your thinking. It is also great to have healthy competition. There is so much to learn.
Have you been having fun finding out about roots and stems? Great! We will now continue to look at leaves this week. Leaves are very important to plants. As you know, there are many different types of leaves as we saw last week. You may look back at the pictures and remind yourself.
Let’s look at parts of a simple leaf. Draw a simple leaf that is different from the one above and label its parts.
A typical leaf consists of two main parts - the blade and the petiole. The leaf blade varies greatly in shape as we have seen in the pictures before. The edges of leaves may be smoothed, toothed, lobed, incised or wavy. The leaf blade may be in one unit, in which case the leaf is called a
leaf, or it may be divided into numerous small parts that look like individual leaves and form a leaf.
The arrangement of a leaf refers to how it grows on the stem. Leaves may be arranged on the stem in a variety of ways. The place on the stem from where the leaves grow is called a node. Some leaves grow opposite, some alternate, some in rosette forms and others in whorls. Let’s look at the veins of leaves.
The veins of leaves may be ● Parallel ● Dichotomous, forming a ‘Y’ ● Palmate, radiating out from a central point ● Pinnate, where the veins are arranged from the midrib
Look at the veins of these leaves Go into the yard and find different shapes and arrangements of leaves and identify them. The texture of leaves may be different. Some may be firm and waxy, shiny, thick, stiff, limp etc. You may find that some leaves may be prickly or have fine hairs. Look at the following leaves that are grouped according to their features. What are the function of leaves? What do leaves do for the plant? Write a few of the functions that you have thought about. Leaves make food for the plant. This is the primary or main function of green leaves. Leaves manufacture food material in the presence of sunlight and chlorophyll. Do you remember what chlorophyll is? Yes, it is the green pigment present in the leaf. This making of food takes place in the presence of water and carbon dioxide. Yes, to make food plants need carbon dioxide, water and sunlight. This is called Photosynthesis is the process by which plants make food. Think of other functions and we will discuss them next week. Until then, goodbye Boys and Girls and remember to pay attention in class!