2. AP Biology Why do Venus flytraps have flytraps?

3. AP Biology Plant Nutrition (Ch 38)

4. AP Biology Physiological adaptation Dogs pee on trees…Why don’t trees pee on dogs?

5. AP Biology Physiological adaptation Dogs pee on trees…Why don’t trees pee on dogs? NH 3 animal waste plant nutrient

6. AP Biology Nutritional needs  Autotrophic does not mean autonomous  plants need…  sun as an energy source  inorganic compounds as raw materials  water (H 2 O)  CO 2  minerals

7. AP Biology Macronutrients  Plants require these nutrients in relatively large amounts  C, O, H, N, P, K, Ca, Mg, S

8. AP Biology Mineral absorption  Proton pumps  active transport of H + ions out of cell  chemiosmosis  H + gradient  creates membrane potential  difference in charge  drives cation uptake  creates gradient  cotransport of other solutes against their gradient

9. AP Biology Micronutrients  Plants require in very small amounts  Cl, Fe, Mn, Bo, Zi, Ni, Mb  primarily cofactors for enzyme function

10. AP Biology Nutrient deficiencies  Lack of essential nutrients  exhibit specific symptoms  dependent on function of nutrient  dependent on solubility of nutrient

11. AP Biology Magnesium deficiency  Symptoms  chlorosis = yellowing of leaves  Why? What is magnesium’s function? Take 2 fertilizer pellets & call me in the morning

12. AP Biology Chlorophyll Why does magnesium deficiency cause chlorosis? The chlorosis shows up in older leaves first, because plant moves Mg + to newer leaves. Why?

13. AP Biology The role of soils  Plants are dependent on soil quality  texture / structure  relative amounts of various sizes of soil particles  composition  organic & inorganic chemical components  fertility Agronomists really dig dirt!

14. AP Biology Importance of organic matter  Topsoil  most important to plant growth  rich in organic matter  humus  decomposing organic material breakdown of dead organisms, feces, fallen leaves & other organic refuse by bacteria & fungi  improves soil texture  reservoir of minerals  organisms  1 tsp. of topsoil has ~5 billion bacteria living with fungi, algae, protists, insects, earthworms, nematodes So don ’ t rake your lawn or bag your leaves

15. AP Biology Soil health as a global issue Not taking care of soil health has far-reaching, damaging consequences  1920’s Dust Bowl  lack of soil conservation  growing the same crop year after year (wheat)  grazing by cattle  bare ground exposed to wind erosion in winter  drought

16. AP Biology Soil health as a global issue  Soil conservation & sustainable agriculture  maintaining healthy environment  sustainable production of food supply  economically viable farming industry contour plowingcrop rotation “A sustainable agriculture does not deplete soils or people.” – Wendell Berry cover crops

17. AP Biology Global issues  soil fertility  erosion  irrigation  forestry destruction

18. AP Biology

19. Fertilizers  “Organic” fertilizers  manure, compost, fishmeal  “Chemical” fertilizers  commercially manufactured  N-P-K (ex. 15-10-5)  15% nitrogen  10% phosphorus  5% potassium What are the political, economic, environmental issues?

20. AP Biology Nitrogen uptake  Nitrates  plants can only take up nitrate (NO 3 - )  Nitrogen cycle by bacteria  trace path of nitrogen fixation! What will the plant use N for? root

21. AP Biology Soybean root nodules  N fixation by Rhizobium bacteria  symbiotic relationship with bean family (legumes)

22. AP Biology Increasing soil fertility  Cover crops  growing a field of plants just to plow them under  usually a legume crop  taking care of soil’s health  puts nitrogen back in soil erosion control, too Plow it under? Why would you that?

23. AP Biology 2006-2007 Some plant oddities…

24. AP Biology Parasitic plants  tap into host plant vascular system  What are the pros and cons? Indian pipe Mistletoe

25. AP Biology Carnivorous plants  Why do they do this?  In what type of environment would they be found? Pitcher plantVenus fly trap Sundew

26. AP Biology Pitcher plants Sundews Venus flytrap Figure 37.15c

27. AP Biology Pitcher plant

28. AP Biology Plants of peat bogs  High acid environment  most minerals & nutrients bound up & are not available to plants  must find alternative sources of nutrients

29. AP Biology Mycorrhizae increase absorption  Symbiotic relationship between fungi & plant  symbiotic fungi greatly increases surface area for absorption of water & minerals  increases volume of soil reached by plant  increases transport to host plant

30. AP Biology REVIEW 1. How is symbiosis critical to plant survival and evolution? 2. How do plants take in nutrients? 3. Name two critical nutrients, and state what outcome their deprivation would have on plants.

31. AP Biology 2006-2007 Any Questions??