1. 1 Seed Plants Gymnosperms & Angiosperms copyright cmassengale

2. 2 Evolution Of Land Plants REMEMBER: Terrestrial plants evolved from a green algal ancestorTerrestrial plants evolved from a green algal ancestor The earliest land plants were nonvascular, spore producers (bryophytes)The earliest land plants were nonvascular, spore producers (bryophytes) Ferns were the 1 st vascular, spore producing plantsFerns were the 1 st vascular, spore producing plants Gymnosperms & angiosperms were the 1 st vascular, seed plantsGymnosperms & angiosperms were the 1 st vascular, seed plants copyright cmassengale

3. 3 MulticellularMulticellular AutotrophicAutotrophic Alternation of GenerationsAlternation of Generations Reproduce by SeedsReproduce by Seeds Vascular tissue for transportVascular tissue for transport Heterosporous – make female megaspores & male microsporesHeterosporous – make female megaspores & male microspores Characteristics of Seed Plants Dandelion dispersing seeds copyright cmassengale

4. 4 Reasons for Success on Land Waxy cuticle Stomata with guard cells to open & close Gametes protected in tissue called Gametangia Pollen tube to transfer sperm to the egg instead of water Seeds protect developing embryo & contain food copyright cmassengale

5. 5 Seeds and Fruits copyright cmassengale

6. 6 Seeds Seeds contain a young, developing plant embryo Seeds are covered with a protective seed coat (testa) Inside is stored food or endosperm that the young plant uses as it begins to sprout or germinate Seeds form from ripened ovules after fertilization copyright cmassengale

7. 7 Parts of a Seed Embryo Primary root or Radicle One or two embryonic leaves called Cotyledons Plumule becomes the shoot Stem like portion below cotyledons called Hypocotyl Stem like portion above cotyledons called Epicotyl copyright cmassengale

8. 8 Endosperm (3n) Seed Coat Cotyledon Plumule Epicotyl Hypocotyl Radicle copyright cmassengale

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10. 10 Seed Dispersal Seeds must be scattered (dispersed) away from the parent plant Testa (seed coats) may last thousands of years Seeds eaten by animals aren’t digested but pass out with wastes copyright cmassengale

11. 11 Seed Dispersal Seeds may have adaptations such as stickers, hooks, or fuzz to adhere to animals copyright cmassengale

12. 12 Seed Dispersal Both water and wind can scatter seeds Wind Dispersal Water Dispersal copyright cmassengale

13. 13 Seed Dispersal Methods copyright cmassengale

14. 14 Seed Germination Early growth of plant embryo Begins when seed absorbs water & breaks seed coat (testa) Embryo uses stored food of cotyledons to begin growing copyright cmassengale

15. 15 Fruits Form when ovary with ovules (eggs) ripens May be dry and hardened (nuts) May be enlarged and fleshy (berries, apples, tomatoes) Used to help disperse seeds copyright cmassengale

16. 16 Types of Fruits Simple fruits – form from a single ovary (apple) Aggregate fruits – forms from several ovaries of the same flower (blackberry) Multiple fruit – forms from several ovaries of different flowers (inflorescence) copyright cmassengale

17. 17 gymnosperrms angiosperms Taxonomy of Vascular Seed Plants Phylum Gnetophyta: Ephedra, Gnetum Phylum Cycadophyta: Cycads Phylum Ginkgophyta: Ginkgo Phylum Coniferophyta: Conifers Phylum Anthophyta: Flowering plants copyright cmassengale

18. 18 Gymnosperm –Intro and evolution –Life cycle and reproduction –Uses and significance Angiosperms: Flowering plants –Intro and evolution –Life cycle and reproduction –Uses and significance –Monocots vs. dicots 12: Gymnosperms and Angiosperms copyright cmassengale

19. 19 GYMNOSPERMS Introduction – Gymnosperm means “naked seed” (From the Greek: gymnos = naked; sperm = seed) More advanced than ferns – do not have spores, they have seeds. The seeds of the gymnosperms lack a protective enclosure (unlike flowering plants which have flowers and fruit). Examples of gymnosperms: Conifers (pine trees), cycads, ginkgo biloba copyright cmassengale

20. 20 Wood produced by gymnosperms Gymnosperms have a very efficient and effective vascular system Usually woody plants Xylem  wood of a tree Phloem  bark of the tree Wood is formed from secondary growth copyright cmassengale

21. 21 Primary vs. secondary growth 1. Primary growth – occurs in apical meristems of shoots and roots Results in increase in length 2. Secondary growth – derived from secondary or lateral meristems Results in increase in girth (width) Common in trees (wood and bark) copyright cmassengale

22. 22 Annual rings Annual rings – xylem formed by the vascular cambium during one growth season Early Spring wood – vessel diameter is large, xylem walls are thinner Late Summer wood – vessel diameter is small, walls are thicker Tropical trees: have no annual rings, because seasons are so similar copyright cmassengale

23. 23 Gymnosperms Mainly woody plants that include Oldest living trees: bristlecone pine, 5000 yrs old! Most massive trees (giant sequoia): up to 375 ft. tall, 41 ft wide! Tallest living trees (redwoods) copyright cmassengale

24. 24 Conifers Conifers adapted to temperate to cold regions Narrow leaves (needles) help to conserve water Covered by resins – for protection from predators, fire, etc. copyright cmassengale

25. 25 Other gymnosperms Cycads – short shrubs, native to tropical regions (look like palms) Ginkgo biloba – a “living fossil”, male and female tree, used as a medicinal plant copyright cmassengale

26. 26 Other gymnosperms Welwitschia – a bizarre gymnosperm plant that grows in Namib desert (So. Africa). Live up to 2000 years in these extreme conditions! Only makes two leaves throughout its life. It takes water from sea mist copyright cmassengale

27. 27 Significance of gymnosperms Ecological importance: Provide food and habitat for wildlife Forests prevent soil erosion Reduce greenhouse-effect gasses Economic and commercial importance: Lumber for wood, paper, etc. Resins – wood, furniture, etc. Ornamental plants (trees, landscaping) Food – pine nuts (pesto, etc.) copyright cmassengale

28. 28 ANGIOSPERMS Angiosperm means “covered seed” Have flowers Have fruits with seeds Live everywhere – dominant plants in the world 260,000 species (88% of Plant Kingdom) Angiosperms are the most successful and advanced plants on earth copyright cmassengale

29. 29 Evolution of Angiosperms Advancements over gymnosperms: Angiosperms have flowers – many use pollinators Fruits and seeds – adapted for dispersal Double fertilization of the endosperm in the seed copyright cmassengale

30. 30 Flower structure Male sex organs: Stamens, composed of anther – organ that produces pollen (male gametophyte) Female sex organs: The carpel Ovary is the enlarged basal portion of carpel that contains the ovules (female gametophyte) The stigma is the receptive portion of the carpel for pollen grains to adhere copyright cmassengale

31. 31 Flower structure Non-reproductive parts: Sepals (green) are the outermost whorl of leaf-like bracts Petals (usually colored) are the inner whorl of leaf-like bracts Both can have various shapes and colors Tepals - _______________ copyright cmassengale

32. 32 Angiosperm lifecycle Flowering plants exhibit alternation of generations. The large, familiar flowering plant is the diploid sporophyte, while the haploid gametophyte stages are microscopic. The unique feature about the life cycle of flowering plants is a double fertilization that produces a diploid zygote and a triploid endosperm or nutritive tissue. copyright cmassengale

33. 33 Double fertilization Pollen grain germinates on stigma forming a pollen tube, which grows down style to the ovary Pollen has 2 haploid sperm nuclei, which travel to the ovary One sperm nucleus fertilizes the haploid egg forming the 2n zygote Another sperm nucleus unites with the 2 polar nuclei, forming the triploid (3n) endosperm copyright cmassengale

34. 34 Seeds copyright cmassengale

35. 35 Monocot vs. dicot Angiosperms are divided into monocots and dicots As the zygote grows into the embryo, the first leaves of the young sporophyte develop and are called as cotyledons (seed leaves) Monocots have one cotyledon (corn, lily, etc). Dicots have two cotyledons (bean, oak, etc). copyright cmassengale

36. 36 Comparing monocot vs. dicot plants FEATUREMONOCOTSDICOTS Cotyledons12 Leaf venationparallelbroad Root systemFibrousTap Number of floral parts In 3’sIn 4’s or 5’s Vascular bundle position ScatteredArranged in a circle Woody or herbaceous HerbaceousEither copyright cmassengale

37. 37 Monocot vs. dicot Number of cotyledons: one vs. two copyright cmassengale

38. 38 Monocot vs. dicot Leaf venation pattern: Monocot is parallel Dicot is net pattern copyright cmassengale

39. 39 Monocot vs. dicot root Monocot: Fibrous root Dicot: Tap root copyright cmassengale

40. 40 Monocot vs. dicot Flower parts: Monocot: in groups of three Dicot: in groups of four or five copyright cmassengale

41. 41 Monocot vs. dicot Vascular bundle position: Monocot: Scattered Dicot: arranged in a circle copyright cmassengale

42. 42 Monocot vs. dicot Stem type: Monocot: Herbaceous Dicot: herbaceous or woody copyright cmassengale

43. 43 Summary: Monocot vs. dicot copyright cmassengale

44. 44 Notice how the importance of the gametophypte dwindles as we move from mosses to ferns to seed plants. The gametophyte of a seed plant is microscopic and not green (does not carry out photosynthesis) copyright cmassengale

45. 45 Lots of specialized terms are used to describe the life cycle of seed plants. This whole structure is an ovule (integument, the cells of the megasporangium, and the cells of the megaspore). The megaspore is formed by meiosis, so is a haploid gametophyte, the rest is diploid sporophyte. copyright cmassengale

46. 46 One of the female gametophyte cells becomes an egg (n). The rest divide to produce the rest of the cells of the female gametophyte. A male gametophyte (n), or pollen grain, enters the ovule, and the nucleus of one of its cells acts like a sperm, and fertilizes the egg (= zygote). copyright cmassengale

47. 47 The haploid female gametophyte (minus the cell that became the egg) becomes a mass of tissue that will provide a food supply for the new embryo developing from the zygote. The integument becomes a hard seed coat. Note that the embryo stops developing until it germinates - thus the “baby plant” in a peanut! copyright cmassengale

48. 48 Gymnosperms are seed plants that do not have a fruit around the seed, and thus have “naked seeds”. Most of us think of gymnosperms as just “pines” (or conifers), but there is quite a diversity. Ginkos live on campus - have you seen one? The “fruit” is not really a fruit, but part of the ovule.. pine gingko copyright cmassengale

49. 49 Angiosperms do not have naked seeds, but seeds surrounded by a n extra layer of tissue that forms a fruit (which may be juicy or dry). Fig. 30.8, 30.9 copyright cmassengale

50. 50copyright cmassengale

51. 51 Almost all angiosperms fall naturally into two groups, monocots (one cotyledon, or seed leaf) and dicots (two cotyledons). A few dicots don’t form a clade, but the huge majoroty that do are called true dicots, or eudicots. Fig. 30.12 (p. 603) copyright cmassengale

52. 52 Angiosperms and animals have evolved very intricate mutualistic interactions involving pollination - interactions that benefit both. copyright cmassengale

53. 53 male cone microsporophyll microsporangium copyright cmassengale

54. 54 female cone scale “megasporophyll” ovule.mega- sporangium copyright cmassengale

55. 55 scale seeds copyright cmassengale

56. 56 Giant Redwood or Sequoia Coniferophyta copyright cmassengale

57. 57 Leaves : Many different sizes, shapes. (Pine needles, cabbage, oak, etc.) * Capture sun’s energy for photosynthesis * Structure of a leaf: - Upper surface cells - Chloroplasts - Veins with xylem and phloem - Underside surface cells - Stomata (“stoma” in Greek means “mouth”, opening) copyright cmassengale

58. 58 The Structur e of a Leaf copyright cmassengale

59. 59 VENATION copyright cmassengale

60. 60 Transpiration = process of evaporation from leaves. * Too much evaporation and the plant shrivels and dies * Closing the stomata helps slow down transpiration. copyright cmassengale

61. 61 Stems : support the plant and carry substances between the roots and leaves. * Some stems also store food (starches) like in asparagus. * They vary in size and shape: - Boabab tree has a huge stems. - Cabbage have short, hidden stems. copyright cmassengale

62. 62 Parts of a Woody Stem copyright cmassengale

63. 63 Annual Rings = xylem rings * Spring Xylem is wide & light brown (grows rapidly) * Summer Xylem is thin & darker (grow slower) * Each pair of light & dark rings = one year’s growth. copyright cmassengale

64. 64copyright cmassengale

65. 65 Roots: (Anchors. Absorbs water & nutrients from soil) * Two Types 1. Taproot = deep into soil 2. Fibrous Roots = several branching main roots * Root structure - Root Cap the rounded tip containing dead cells. - Root hairs increase surface absorption area - Cambium produces xylem and phloem tissues. - Xylem transports substances up to the plant - Phloem brings food down to the growing root copyright cmassengale

66. 66 Tap Root Fibrous Roots copyright cmassengale

67. 67 Root: Internal Structure copyright cmassengale

68. 68 Roots do not absorb water and minerals through a smooth Epidermis. Tiny, hairlike projections called ROOT HAIRS on the epidermis absorb water and dissolved minerals from the soil. Root Hairs also INCREASE the Surface Area of the Plant Roots. copyright cmassengale

69. 69 Gymnosperms Gymnosperm = seed plant that produces naked seeds. * Many have needlelike or scalelike leaves and deep root systems. * Note the book says fossils indicate there were many more gymnosperms in the past than today. This is because the global flood 4,000 years ago wiped out many plants. (The dates given by many books of millions of years are false guesses. See the booklet by Dr. Humphreys.) copyright cmassengale

70. 70 Types of Gymnosperms: - Cycads (look like palm trees with large cones) - Ginkgo (only the Ginkgo biloba survives today) - Gnetophytes (found only in deserts - Conifers (largest & most common, pines, cedars, etc.) [Conifers are evergreens: keep needles all year] copyright cmassengale

71. 71 Oldest living organism – Bristlecone Pine About 4,000 years old copyright cmassengale

72. 72 Reproduction of Gymnosperms: * Cones – covered in scales, both male and female cones are produced. - Pollen is produced by male cones, and pollen are tiny cells that later become sperm cells. - Ovule is a structure containing an egg cell. Pollination = transfer of pollen from male structure to female part. (Pollen falls from a male cone to a female cone and fertilizes an ovule, which develops into a seed, with the zygote as the embryo part of the seed. It can take two years for seeds to mature, then the cones open & wind carries the seeds off.) copyright cmassengale

73. 73 Angiosperms Angiosperms – Two characteristics: 1. flowers 2. fruit (To remember, think: “Angie” likes flowers, but “Gym” does not.) * They produce seeds inside a fruit. * Flower = angiosperm reproductive structure * Fruit starts as an Ovary = where the seeds develop copyright cmassengale

74. 74 Flower Structure : Not all flowers have same parts. Some have only male parts. * Sepals = leaf-like structures covering a bud. * Petals = colorful structures of an open flower. * Stamens = male parts (stalks topped by knobs) * Pistils = the female parts in the center of the flower. - Stigma = sticky tip of the pistil - Style = tube connecting stigma to ovary. copyright cmassengale

75. 75 The Structure of a Flower copyright cmassengale

76. 76 Life Spans of Angiosperms: * Annuals = complete a life cycle in one year. (pansies, wheat, tomatoes, cucumbers, etc) * Biennials = complete life cycle in two years. (Second year they produce flowers and seeds.) (Parsley, celery, etc) * Perennials = live for more than two years (Oak tree, honeysuckles, etc) (Roots and stems survive the winter) copyright cmassengale