PLANT CELLS TISSUES AND ORGANS

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1 PLANT CELLS TISSUES AND ORGANS How does a single seed cell change into a seedling and eventually an adult tree? The answer lies in the processes of and the concept of. CELL SPECIALIZATION In general as cells go through mitosis they produce 2 with genetic information. At some point in their development, cells that start out the same undergo, resulting in cells specialized for different functions. This specialization results from certain in the cell being activated and specific being produced. SPECIALIZED CELLS AND TISSUES IN PLANTS Groups of specialized cells form and groups of tissues work together in such as,, and. Specialized cells called or are responsible. These are cells that can be directed to form specialized tissues. These cells combine to form the three major tissues found in a plant: TISSUE FUNCTION

2 TISSUES WORKING TOGETHER Plants have 3 or 4 organs: THE LEAF upper and middle leaf 1) Use a microviewer or microscope to observe a prepared slide of a leaf cross section. 2) Identify the structures on the slide shown in the above diagram. 3) Describe or give the function of each leaf cell labelled in the diagram below.

3 THE LEAF lower leaf surface 1) Observe the lower leaf surface. 2) Locate the stomata on the prepared slide and label the above diagram. 3) Describe the function of the stomata. 4) Observe the demonstration slide of working stomata. THE CHLOROPLAST AND PHOTOSYNTHESIS Photosynthesis occurs in specialized organelles called found in plant cells. Photosynthetic plants are able to create their own food based on the following balanced chemical equation: Task: 1) Copy figure 2.9 of a chloroplast into your notes. (left diagram)

4 THE STEM The plants stem has 2 main functions: i) ii) In your own words describe the development and function of xylem. _ The xylem vessels are grouped with vessels in, with the strength of each vessel adding to the strength of the others. In your own words describe the formation and function of phloem. 1) Create a simple labelled diagram showing the relationship of xylem and phloem in your notes. (use figure 2.1 on page 64 question 3 and its diagram on page 69) 2) Using a microscope or microviewer, observe the prepared slides provided by your teacher. 3) Look for and identify the parts that you labelled on your diagram from question 1 above.

5 ROOTS Roots a plant to the ground and allow it to take up and from the soil. Some roots also act as a plant s area. A is a good example of this. Another example of this storage would be a. The root consist of the outer layer called the, a middle layer of ground tissue called the and a inner layer of ground tissue called the. Inside the pericycle is vascular tissue, the and. Briefly discuss the function of: Pericycle Cortex 1) Label the cross section of a root. 2) Use a microscope or microviewer to observe and identify the parts labelled in your diagram.

6 Types of Roots ROOT TYPE DESCRIPTION & FUNCTION EXAMPLE & DIAGRAM Taproot Fibrous root PLANTS UNDER ATTACK Plant tissues and organs can be attacked by much the same as animal tissues and organs. More than different viruses are known to infect plant cells causing as many as plant diseases. Two specific examples of theses and their impact are: i) ii)

7 Plant Galls Plant galls are similar to in animals. These are caused by growth of groups of cells. Plants can produce galls in response to by organisms such as,,, and. The attackers have a purpose. They use the plant s to support themselves and their offspring. Insects promote the development of by injecting a chemical in to the plant s tissues. These chemicals interact with the plant s fluids and which are turned on and off in the cells. This stimulates a change in growth of a where young insects develop. The most significant difference between plant galls and animal tumours is: THE FLOWER 1) Read page 68 and summarize it in your own words in your notes. 2) Search the internet for a diagram of a flower with parts labelled and include it in your notes. 3) Answer questions 1, 5, 6, 7 on page 69