1. 6 th Grade - plants

2. Purpose of plants  Why do we need plants???

3. Leaves  Purpose of leaves  to produce food for plant

4. Needs of Leaves Needs of Leaves:  Water – from the ground  Air – through the stomata (stoma) – little holes in the bottom of the leaf  Light – from the sun

5. Photosynthesis  Photosynthesis – The chemical process by which green plants produce food  without photosynthesis plants cannot grow  Plants are the only living things that can make their own food  All life depends on plants

6. Definitions of photosynthesis  Chlorophyll – the pigment (coloring) that makes plant green  Chloroplasts – tiny packages of chlorophyll contained in the cells of the leaf  Glucose – a type of sugar that plants need to live  Leaves also make proteins and vitamins for plant’s nourishment

7. Process of Photosynthesis

8. Parts of a leaf VEIN MIDRIB STEM

9. Parts of a leaf  Stem – joins the leaf to a plant  Vein – spread outward from the stem, transport liquids and reinforce structure  Midrib – large vein that runs straight up the middle of the leaf  Color – most food making cells (top)  Cuticle – waxy covering that coats the skin of a leaf and prevents water from escaping

10. Special Leaves TTTTwining climbers VVVVines – plants that climb upwards as they grow by clinging to tall objects TTTTendrils – special leaves that are the hands with which a vine grasps a support structure

11. TTTTasty storage space TTTThese leaves grow partially below the ground. They insulate the plant in the cold. MMMMany layers of lower leaves that remain below the ground for a bulb. Ex. onion

12. PPPPrickly Protection SSSSpines – of cacti are special leaves that contain no chlorophyll SSSSpines protect the water storing stem of the cactus plant

13. IIIInsect Eaters ““““insectvorous” insect eaters CCCContain chlorophyl (manufacture their own food) but also obtain some food from bodies of their victims

14. Insect Eaters  Venus fly trap  Leaves are hinged so they can close like jaws of a steel trap  Tiny hairs on the inside trigger the jaws when touched by an insect

15. Insect Eaters  Bladderwort  Underwater plant  Hollow, bladder-like leaves filled with water  When trigger hairs are bumped the leaf expands and creature is trapped as water is sucked into the leaf

16. Insect Eaters  Pitcher plant  Attracts insect with its bright color leaves and smell of its honey like nectar  When an insect lands on the rim it slides down the slippery sides and becomes trapped

17. Insect Eaters  Sundew  Attracts insects with its glistening bait – sticky “dew drops”  Insects get stuck on the dew drops and then the long hairs close around it.

18. Roots and Stems  Shoot System – every part of the plant visible above ground  Root system – part of the plant located below the ground

19. Roots Roots:  Always grow downward  Anchor plant in soil; keep soil from washing or blowing away  Main job is to absorb water and minerals for the plant’s use  Taproot – main root that goes deep into the ground to locate water

20. How a root functions  A root grows only at its tip. The root cap is a layer of protective cells that cover the tip. Root hairs, tiny projections near the end of the root, worm their way through the soil to find water. Roots absorb more water than is necessary. Water that is not needed evaporates through the stomata.

21.  Roots are the shipping and receiving warehouse for the plant (bring in water and minerals to the leaves; store extra glucose, food)  Roots store extra sugar by converting it into substances called starches

22. Stems Plant Super highway with 2 pipelines  1. carries water and minerals from roots to leaves  2. carries dissolved food from leaves to stem to roots

23. Parts of stems  Stem tip – upper part – produces plant’s growth  Cellulose – tough material made by plant cells, forms a strong cell wall around each plant cell  Cell Wall – outer membrane of plant cell  Stolon (runner) – stem that grows along the surface of the ground  Rhizomes – thick storage stems below the ground that help produce new plants

24. Tropism Def: growth of a plant in response to a condition in its environment 4 types of Tropism  Geotropism – plant’s response to gravity  Hydrotropism – plant’s response to water  Phototropism – plants response to light  Thigmotropism – plants response to touch