Plants: Roots, Stems, Leaves, seeds and Flowers

1. Plants:Roots, Stems, Leaves, seeds and Flowers

2. Why are Plants so Important? • Produce oxygen • Take out carbon dioxide from our world • Can be used to make medicine • Can be used as shelter • Make food (so we have energy) • Can make paper, desks, walls, etc

3. Parts of a Plant

4. Label all parts of plant • Words to use: • - Root - Flower • - Stem - Fruit • Leaves - Seeds

5. Roots – 2 types a) Taproot b) Fibrous Example: Carrots, Turnips Examples: Corn, Beans

6. Functions of ROOTS • Anchors to hold plants in place • Absorb water and minerals • Transport water and minerals to stem • Sometimes used for food storage

7. A Closer Look at Roots

8. Cross Section of a Root

9. How Can Plant Roots Get Damaged? • Adding chemicals to soil (pesticides, chemical waste, etc) • People cutting down trees – chopping off the roots • Putting salt on roads – salt ends up in the Earth/soil • Forest fires (destroy plants and their roots)

10. What happens when a plant’s roots are damaged? • Plant will not grow and die

11. What makes the roots grow downwards? • A hormone inside the plant detects gravity and causes root cells in the bottom tip to reproduce. • This is called ‘gravitropism’

12. Let’s Look at Stems now 

13. Functions of Stems • To hold leaves up to the sunlight • To transport materials between roots and leaves • Food Storage (Example: Irish potato tubers) • Protection (Example – thorns) • Can be used to create new plants • Can carry out photosynthesis (if stem is green – like cactus plant)

14. Stems – 2 types a) Herbaceous b) Woody Example: Tulips Examples: Trees and shrubs

15. Annual Rings • Each year an ‘annual ring’ forms • Scientists count up these annual rings and determine the age of the plant. • Scientists examine the thickness of these annual rings to determine the length of the growing season (i.e. how long summer was, etc)

16. Cross Section of a Stem

17. How Can Plant Stems Get Damaged? • People/animals cut down trees • Harsh weather (like snow, high winds, floods) can break off branches • Acid precipitation • Forest fires

18. What happens when a plant’s Stems are damaged? • Transport of food/water to leaves does not happen – can lead to plant death • Plant not supported properly – so plant falls over • No photosynthesis in green stems

19. What makes the Stems grow Upwards? • A hormone inside the plant makes the stems (shoots) grow upwards • This is also called ‘gravitropism”

20. PLANT TISSUES • Dermal: the outermost cell layers, which protect the plant from cuts, invasion by microorganisms, and water loss. • On leaves and stems, these cells produce a waxy cuticle, like on an apple. They may also produce fine hairs (e.g. peach fuzz) or skin irritants.

21. PLANT TISSUES • Meristematic: cells that divide by mitosis; area of growth • Ground tissue: internal, nonvascular tissues, e.g. the “fleshy” part of apples and pears, may perform functions such as photosynthesis and food storage.

22. Tissues Cont: • Vascular Tissue: • Xylem: conducts water and minerals from the roots to the rest of the plant. • Phloem: food-conducting tissue; transports sugars and other plant products from one part of the plant to another.

23. That’s it for Day 4 work. Now work on HW: p7 and 4.8 #1-5, 7

24. Its all about the Leaves

25. Main Functions • Primary site of photosynthesis • Must be able to: • Capture sunlight • Be able to carry out gas exchange • Prevent dehydration • Regulate water loss by opening and closingguard cells • Storage (for food and water) • Support (like for the tendrils on grape vines)

26. If carrying out photosynthesis was the main function of leaves, then why aren’t all leaves very wide? If leaves were too wide, then leaves would dry out too quickly

27. Basic Leaf Structure

30. How Can Plant leaves Get Damaged? • Insects eating them • Pesticide use (burns leaf/prevent photosynthesis) • Acid rain can burn the epidermis • Forest fires and natural disasters

31. What happens when a plant’s leaves are damaged? • No photosynthesis can occur • This means: - no oxygen, no food being made - animals that eat plants die

33. PHOTOSYNTHESIS SUN + WATER + CO2 GLUCOSE + OXYGEN

34. Fruit/Flowers 

35. Main Function of Fruits/Flowers • To help plant produce a new plant (help hold and protect genetic information and later on get the seeds/pollen/spores out)

37. Life Cycle of Flowering Plants • Male gametes = pollen grains, produced by the stamen (male part of flower, consisting of filament and anther)

38. Life Cycle of Flowering Plants • Female gametes (eggs) are in the pistil (female part of flower), consisting of the sticky stigma, and the ovary) • Eggs are located in spaces called ovules in the ovary

39. Life Cycle of Flowering Plants 1) Pollen carried by wind/animals to other flowers, grows down into the ovary 2) The zygote develops, and a seed is formed 3) The seed (with or without fruit) is released

40. What’s with these Seeds …

41. Seeds vs. Spores • Seeds – have genetic information and nutrition (fleshy part) • Spores – only genetic information (no food or nutrition, no fleshy parts)

42. Main Function of Seeds/Spores • To hold genetic information and create new plant

43. Parts of a Seed • Seed coat – protects embryo • Embryo - little plant - contains food to nourish plant • Seed leaves (cotyledons) - provide the necessary food energy until roots and true leaves form.

45. Is a Bean plant a Monocot or Dicot?Is a Corn plant a Monocot or Dicot?

46. How Can Plant Seeds/spores Get Damaged? • Humans touching them and destroying them • Acid rain • Chemicals being thrown onto plants • Too much heat/cold

47. What happens when a plant’s Seeds/spores are damaged? • Plant will not grow