Obj. - Students are analyzing the results of typical experiments involving BTB indicators and designing additonal experiments that will test their ideas about the cellular activities of plants.
Activities:
1.) Open Note Quiz: POST to the website the definitions to 10 of the terms from your term list. This quiz is due no later than 8:30pm today, May 1, 2009.
2.) Analyze the results of the BTB experiments and decide which type of experiment you will perform next week.
IN YOUR SCIENCE NOTEBOOK, answer the following questions and complete the data table:
1. What do you think is going on in these experiments? (The experiments were set up using BTB, a chemical that changes color in response to the gases dissolved in water)
2. What do we know about BTB?
1.) It is blue in a neutral solution.
2.) It is yellow in a weak acid.
3.) When carbon dioxide from the lungs is inhaled into BTB, it reacts with water to form carbonic acid.
Test tubes contain 1 plant, blue or yellow BTB.
Students were told that their experiments would represent either the process of cellular respiration or photosynthesis, and they had to use the results of the experiment to provide evidence for one or the other taking place.
What do we know about cellular respiration?
Write the equation for cellular respiration IN YOUR NOTEBOOK:
What do we know about photosynthesis?
Write the equation for photosynthesis IN YOUR NOTEBOOK:
Complete the data table by analyzing the results of several different experiment results:
Experimental Setup #1
Blue BTB uncovered and left overnight. Results: No Change. Analysis: Dissolved carbon dioxide in the BTB is the same as that in the air.
Experimental Setup #2
Yellow BTB uncovered and left overnight. Results: BTB turns more green/blue (lower CO2 level). Analysis: Carbon dioxide levels are beginning to be the same as the room air.
Experimental Setup #3
Plant in blue or yellow BTB in light. Results: BTB stays blue or turns blue (lower CO2 levels).
THIS IS THE SECTION FOR YOUR ANALYSIS> YOU MUST INCLUDE ANSWERS TO THESE SECTIONS TO RECEIVE YOUR POINT> > >
Analysis: If photosynthesis occurred, what gas molecules would be used by the plant? If CO2 levels were decreasing, where would the solution obtain additional dissolved CO2? (From the air, or from the plant?)
Experimental Setup #4
Plant in blue or yellow BTB in the dark. Results: BTB turns yellow or stays yellow (higher CO2 levels).
Analysis: Does the plant create CO2 during cellular respiration? What is the equation for cellular respiration (see your textbook, or an online resource)? Do plants actually produce carbon dioxide in addition to oxygen? Why or why not?
Experimental Set up #5
Animal in blue or yellow BTB Results: BTB turns yellow or stays yellow (higher CO2 levels).
Analysis: Do animals create CO2? Why or why not?
Assessment: You will be given the following materials to design your experiment (Elodea, BTB, beakers, lights, water, etc.)
1. Draw or diagram your experiment in your notebook.
2. How will you investigate the production of carbon dioxide by your plant?
3. How will you determine whether the plant is producing more or less CO2 than it is using up?
POST your answers to questions 1-3 before class on Monday, May 4th.
1 comment:
Ron Reed
1. Cell respiration- when plants use stored energy to grow with out light
2. Photosynthesis- when plants use light and convert it to energy to grow.
3. pollen- pollen is like a sperm for plants.
4. pollination- when pollen goes into the ovary of a plant.
5. reproduction- is when plant are pollenated and they seed.
6. flowers- are plants that grow naturally.
7.chloroplasts- is in side a plant and it gives the plant its green color.
8. ions- are very small parts of a cell.
9. molecule- is the smallest part of a plant.
10. vegetables- are plants the reproduce on their own without pollination.
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