Stomata Lab

vocabulary word! Stomata – small openings found on the underside of a leaf. Stomata allow passage of gases into and out of the plant leaf. This is the site where carbon dioxide is taken into the leaf and oxygen is released from the leaf. Water can also exit the leaf through these pores.

The stomata pores are surrounded on both sides by jellybean shaped cells called guard cells. These cells expand or contract to open or close the stomata. Guard cells also close when the plant is dehydrated or in dry weather to keep more water in the plant.

The number of stomata on the underside of a leaf can tell a lot about a plant. Usually, a high concentration of stomata indicates fast growth and a wet climate. Lower concentrations of stomata indicate lower rates of photosynthesis and growth and are adaptations for dry weather.

Under your definition, draw a diagram of a stomata.

http://www.youtube.com/watch?v=IlmgFYmbAUg

vocabulary word! transpiration – the evaporation of water into the atmosphere from the leaves and stems of plants. Draw a diagram of transpiration under your definition.

We will create a lab report on your paper for today. Write “observation:” then answer this question - What is in the plastic bag placed around the leaves overnight?

What question could you ask about the colors in this leaf? Write the word “question:” Where is the water coming from?

What do you think the final result of the experiment will be? Write the word “hypothesis:” Write down your prediction of what will happen during the experiment. Youe hypothesis will answer the question you just wrote. It should be a statement and a complete sentence.

Procedure You have three different leaves on your desk. As a table, you will explore both sides of the leaf using the digital microscopes. Pay special attention to the underside of the leaves.

On your paper, draw three boxes and label them “leaf 1”, “leaf 2”, and “leaf” 3. In each box, draw and color a sketch of the underside of each leaf.

Open and Closed Stomata

Open and Closed Stomata

Chlorophyll

Write down the results of the experiment. Write the word “data:” Write down what you saw on the video and the microscope pictures. Describe it in as much detail as you can.

Based on what you saw, how would you answer your original question? Write down the your conclusion. Write the word “conclusion,” then answer this question. Based on what you saw, how would you answer your original question?

Complete the worksheet for the lab Complete the worksheet for the lab. You may work with other students at your table and use the internet to research the extension questions.