AN INTRODUCTION TO PLANTS

Picture
Copyright to ExcroFlor Canada

Objectives

  • Understand the characteristics of plants, their importance on the planet
  • Learn the anatomy of a plants
  • Identify different parts of a plant and their functions

Materials

  • Projector to show picture 
  • Blackboard/Chalk
  • White paper

An introduction to plants (10 minutes)

Question the students first about what they know on plants. And make them discuss and bring out everything they know. Write all the words on the board. And then explain that we will be looking at plants and their impact on our lives.

Plants are alive, just like people and animals. How do we know this? There are certain characteristics that are specific to all living things on the planet. First, they grow and die. Another factor is that they also need energy, air, water and nutrients to survive. Living things have an ability to reproduce and are made up of cells. They can also be stimulated and react to their surrounding. All these charactertistics apply to plants.
 


Anatomy of a PLant (35 minutes) 

A plant body is made up of three major parts: root, leaf and stem.  Leaves and stems form a shoot.  Each part contains the three major tissue types.  Root is often under the ground and anchors the plant.  From cross section, a typical root contains epidermis, cortex, endodermis and vascular bundles.  From longitudinal view, a root contains a root tip which functions in gravity sensing, a zone of cell division, zone of elongation and zone of maturation.  The function of a root is for anchorage of the plant, and water and mineral uptake.  A stem is the part of the plant from which shoots and buds arise.  The function of stem is for support of the plant, for transportation of water, mineral and food.  Some stems have storage and reproduction function.  Stems have specialized structure celled xylem and phloem for transportation 

Picture
Scanned from Encyclopedia Brittanica
Learn the definitions and functions of the following parts:

Root:
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial (growing above the ground) or aerating. The first root that comes from a plant is 

called a radicle.

The root has 4 different functions in a plant:
         1) absorption of water and inorganic nutrients, 
         2) anchoring of the plant body to the ground 
         3) storage of food and nutrients
         4) to prevent soil erosion. 
 
Shoot:
Shoots are new plant growth. They include stems, flowering stems with flower buds, and leaves. Shoots should not be confused with stems. Shoots are often consumed by animals because the fibres in the new growth have not completed secondary cell wall development. That simple fact makes the shoots soft and easier to chew. However, as the shoot grows older, the cells develop, mature and become harder and have a tougher structure. 

Petal:
Petals are modified leaves that surround the reproductive parts of flowers. Petals are often colorful and come in many different shapes to attract pollinators. Sepals are found directly beneath the petals. In a flower, when a petal and sepal look alike, they are called tepals. 

Petiole:
petiole is the small stalk. It has the function of attaching the leaf to the stem. The petiole has the same internal structure as the stem. It is sometimes called mini-stem.

Stem:
Located above the soil surface, a stem is one of two main structural axes of a plant. The stem is divided into two parts: nodes and internodes. The nodes hold buds which grow into one or more leaves, petals, cones or other stems. The internodes are used to distance one node from another.

Leaf:
The leaf is another main organ in a plant. It is responsible for carrying out photosynthesis (which will see later). It is an above-ground organ that is ideally flat (laminar) and thin. The flatness of leaves works to maximally expose the chloroplast of plants to more light and increase the absorption of carbon dioxide at the expense of water loss.  

Chloropasts:
Chloroplasts are organelles found in plant cells and in any organism that is able to conduct photosynthesis. Chloroplasts are the organelles that capture light energy to conserve ATP.        


ACTIVITY

(10 minuteS)

1.  Take a out a piece of blank sheet 
2. Draw a picture of a plant 
3. Label all the parts we looked at today without looking at the 
   book (teacher will hide away the picture above) 
4. Label as many as you can on your own 
5. Get in groups of 2 and try to complete each other's drawing 
6. The teacher will show you the answer