The Water Cycle and Plants

1. The Water Cycle and Plants

2. Water Cycle • Essential to all organisms

3. Water Cycle • Essential to all organisms • Availability influences the rate of ecosystem processes

4. Water Cycle • Essential to all organisms • Availability influences the rate of ecosystem processes • Driven by solar energy

5. Water Cycle Draw, label and describe in your notebook

6. Water Cycle Size of arrows show relative amounts

7. Evapotranspiration • When water evaporates out leaves into the atmosphere, other water molecules are pulled up the plant.

8. Evapotranspiration • When water evaporates out leaves into the atmosphere, other water molecules are pulled up the plant. • Plants move water against gravity!

9. Evapotranspiration • When water evaporates out leaves into the atmosphere, other water molecules are pulled up the plant. • Plants move water against gravity! • Due to cohesive properties of water (water molecules stick well to other water molecules)

10. Plants make their own food in their leaves. Photosynthesis Carbon dioxide + water + light energy  glucose + oxygen They have evolved structures to do this job…

12. Epidermis • outer layer of cells • acts like a protective “skin” for the leaf

13. Cuticle • waxy coating covering the epidermis • stops evaporation of water

14. Stomata • openings in the lower epidermis • Surrounded by two guard cells • Allow gas exchange: CO2 in and O2 out

15. Mesophyll • Main inner leaf tissue • Most of photosynthesis takes place here • Upper part of leaf mesophyll is tightly packed with cells full of chloroplasts

16. Vascular Tissues • Xylem carries water from the roots to the leaves • Phloem carries sugars produced during photosynthesis in the chloroplasts of leaves to other places in plant • Both found in vascular bundles in the veins of the leaf

17. Let’s look at vascular tissues in celery stems and leaves