Stomata Condensation by Plants

1. Stomata Condensation by Plants Presentation by: • Ladan Soroosh • Chandani Sompura • Vanessa Kaye • Allison Kreis

2. Plant Environments • Plants can live in extreme climates. • Not all plants grow all over the world. • Small changes have enabled plants to survive in certain environments. • Many elements make up plant’s environment. • E.g. sunlight, temperature, precipitation, & natural community.

3. Biomes: Natural Communities • 6 Biomes: tundra, forests, chaparrals, grasslands, savannas, & deserts • Forests cover 1/3 of the earth’s land • 3 major groups: coniferous forests, temperate deciduous forests, & tropical rain forests

4. Plant 1 • Dracaena: temperate deciduous plant • Temperate deciduous forests cover large areas of North America. • Most areas have cold winters & warm, wet summers. • Mostly called broadleaf trees • Lose leaves every fall & grow new ones in spring.

5. Plant 2 • Hawaiian Ti Plant: tropical plant • Grow in warm, wet weather, year round. • Most are broadleaf, & do not lose leaves completely • Heavy rainfall occurs throughout the year.

6. Plant 3 • Lantana: desert plant • Deserts cover about 1/5 of the earth’s land. • All deserts receive little rain & have either rocky or sandy soil. • In most deserts, the temperature rises above 100º F, for most of the year.

7. Plant 3 (Cont.) • Desert plants are dispersed. • Roots of most plants extend over large areas, to capture as much water. • They usually have small leaves to conserve water by reducing surface area from which transpiration occurs. • Stomata are closed during the day.

8. What is a stoma? • Pore-like structure on leaves and stems • Pore is surrounded by guard cells with bands of cellulose micro fibrils

9. Function of Stomata • Allows CO2 to diffuse into the leaf, while water vapor diffuses out • Controls the amount of gas diffusion and water transpiration

10. Environmental Factors • Stomata will open if: • There is light • Low levels of CO2 in the leaves • Stomata will close if: • Plant is losing a lot of water • It is nighttime (for most plants)

11. Mechanism to control opening of the pore • Proton pump activated • Active Transport of K+ into the cell • Increase in negative water pressure • Water enters cell • Increase turgor • Pore opens

12. Mechanism to control closing of the pore • Proton pump deactivate • K+ leaves via passive diffusion • Water follows via osmosis • Decrease turgor • Pore closes

13. Procedure: • Materials: • Get 3 plants • Tropical plant • Desert plant • Temperate deciduous plant • Eye dropper • Small plastic measuring cup • Nail polish • Scotch tape • Plastic bags • Microscope with slides

14. Beginning of first 24-hr period • Give water to plants • 90mL of water to each with an additional 30mL to the desert plant • Cover each plant with a plastic bag, leaving a small opening (~2-3 in) at the bottom

15. Beginning of second 24-hr period • Carefully remove bags from plants • Using eye dropper, collect water-droplets from leaves • Empty dropper contents into measuring cup, while counting how many drops were collected • Record data • Give water to each of the plants • 30mL of water

16. End of second 24-hr period • Measure amount of water released by each plant • Record data

17. Third 24-hr period • Add 30mL of water to each plant • Measure amount of water released by each plant

18. Final Steps • Select leaves to view under microscope • Cover portion of leaf with nail-polish and let dry • Pull nail-polish layer off leaf with scotch tape • Place the tissue layer on a slide and focus it under a microscope

19. Results

20. Results (Cont.)

21. Results (Cont.)

22. References • “Plant,” World Book. 1999 World Book, Inc. Chicago IL. • “Desert,” Microsoft Encarta Encyclopedia 2000. 1993-1999 Microsoft Corporation. • http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/G/GasExchange.html.