Slide 1 / 86. Angiosperms: The Flowering Plants

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1 Slide 1 / 86 Angiosperms: The Flowering Plants

2 Slide 2 / 86 Brief Phylogeny of Plants Monocot Dicot This presentation will focus on angiosperms Angiosperm Gymnosperm Seeded Plants Non-Seeded plants Vascular plants Non-vascular plants Aquatic plants

3 Slide 3 / 86 Angiosperms Angiosperms are the flowering seed plants. Angiosperms have dominated the land for over 100 million years and there are about 250,000 known species. Most of our foods come from a few hundred domesticated species of flowering plants. Roughly 70% of angiosperms are polyploid.

4 Flowering Plants Slide 4 / 86 Examples of Angiosperms Deciduous Trees (Trees that loose their leaves in a yearly cycle) Some Grasses

5 Slide 5 / 86 Monocots and Dicots The two main groups of angiosperms are the Monocots and the Dicots. Monocot Dicot The term monocot and dicot refer to the first leaves that appear on the embryo of the plant, the cotyledon.

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7 Slide 7 / 86 Examples of Dicots Fruit Trees Grape Vines Magnolia Tree Pumpkin Patch

8 Slide 8 / 86 Differentiating Monocots and Dicots Monocots and Dicots can be distinguished from each other by looking at a number of identifying traits. These traits include seed leaves, leaf veins, stems, flowers, and roots.

9 Slide 9 / 86 Cotyledon As we already mentioned, the cotyledon is an embryonic seed leaf, which is the first part of the plant to appear after it emerges from its seed. Monocot has one cotyledon Dicot has two cotyledons

10 Slide 10 / 86 Monocot Dicot seed coat seed coat endosperm one cotyledon embryo endosperm two cotyledons embryo

11 Slide 11 / 86 1 A dicot has one cotyledon. True False

12 Slide 12 / 86 Leaf Veins Monocots have parallel leaf veins while dicots have branched leaf veins

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14 Slide 14 / 86 Stem Vascular Bundles The vascular tissue which transports water and nutrients up the stem of the plant has different arrangements in monocots and dicots. Monocots have bundles in complex arrangements Dicots have vascular bundles in a ring

15 Slide 15 / 86 3 This is the stem of a dicot. True False

16 Slide 16 / 86 Flower Petal Arrangements The floral petals on each plant differ in total number. Monocots have petals in multiples of three, while dicots have petals in multiples of four or five. Monocot Multiple of 3 Dicot Multiple of 4 or 5

17 Slide 17 / 86 4 Is this flower a monocot? Yes No

18 Slide 18 / 86 5 This flower is a monocot. True False

19 Slide 19 / 86 Roots Monocots have a fibrous root system, while dicots typically have one taproot.

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22 Slide 22 / 86 Adaptations The adaptations allow plants to function on terrestrial habitats without drying out. Plants need to absorb water and minerals from the soil, CO 2 from the air, and light from the sun.

23 Slide 23 / 86 The plant body Two main sections to the plant body: the roots and the shoots. shoots roots

24 Slide 24 / 86 Functions of the Root System The 3 functions of the root system are to: (1) anchor the plant (2) absorb and transport minerals and water (3) store food

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26 Slide 26 / 86 7 The main function of the root hair is to A B C D increase anchoring power of the plant increase surface area for absorption protect roots from freezing temperatures provide a passageway for nutrients

27 Slide 27 / 86 Shoot System The shoot system consists of the stems, leaves, and reproductive structures

28 Slide 28 / 86 Stems are composed of nodes, where leaves, flowers, and other stems attach. Space between the nodes is the internode. Parts of the stem Leaves are composed of photosynthetic blades and short stalks that attach at the nodes. Leaf

29 Slide 29 / 86 Buds Buds are undeveloped shoots which have the potential to grow into nodes, internodes, and leaves.

30 Slide 30 / 86 Terminal Buds are found at the top of the plant and are responsible for the growth in height. Axillary (or lateral) Buds are found at each point of attachment for a leaf and the stem and are responsible for growth in width. Types of Buds

31 Slide 31 / 86 Apical Dominance Apical Dominance results from the release of the hormone Auxin by the terminal bud which inhibits the growth from the lateral buds. To made a plant bushier, you remove the terminal bud, which then allows for growth from the lateral buds. This is because the bud is removed, which means the hormone suppressing the growth is also removed. This is also why pruning makes fruit trees produce more fruit.

32 Slide 32 / 86 8 Removing the terminal bud of a plant will cause: A B C D an increase in the root system an increase in the size of the leaves increased axillary bud growth a plant to lose the ability to flower

33 Slide 33 / 86 Structural Modifications Based on their functions, many plants have modified structures. Typical structures modified are roots, stems, and leaves.

34 Slide 34 / 86 Modified Roots Many dicots have modified taproots. Carrots, beets, turnips, and sweet potatoes are all roots modified for storage of carbohydrates. The plants use the stored starches for flower production. This is why root crops are harvested before they flower.

35 Slide 35 / 86 Modified Stems A stolon is a modified stem who's purpose is to provide a means for asexual reproduction. Rhizomes (like ginger) and tubers (like potatoes) are underground stems that store starch.

36 Slide 36 / 86 Modified Leaves Spines offer protection Tendrils are modified for grasping

37 Slide 37 / 86 9 A stem modified for nutrient storage is called a A B C D taproot runner tuber bulb

38 Slide 38 / 86 Review: Unique features of plant cells many plant cells are photosynthetic and contain chloroplasts most plant cells have a large central vacuole that helps support the cell and keep it firm plant cells have a cell wall composed of cellulose that surrounds the plasma membrane

39 Slide 39 / 86 Review - Identify the parts of plant cells

40 Slide 40 / Which structure is found in both plant and animal cells? A B C D chloroplasts mitochondria cell walls all three are unique to plant cells only

41 Slide 41 / 86 Everything always goes back to reproduction "An oak tree is just an acorn's way of making more acorns"

42 Slide 42 / Review: Angiosperms are plants. A B C D cone-bearing vascular flowering seedless

43 Slide 43 / 86 The Flower The flower is the reproductive shoot of an angiosperm. It is composed of modified leaves (petals, sepals, stamens, and carpels). The parts of a flower are both male and female.

44 Slide 44 / 86 Structure of a Flower Sepals are green and protect the flower buds.

45 Slide 45 / 86 Structure of a Flower Petals are large, colorful, showy, and used to attract pollinators.

46 Slide 46 / 86 Structure of a Flower Stamens are male structures with pollen-bearing anthers on the tip of a filament. The pollen grains deliver the sperm nuclei to the females.

47 Slide 47 / 86 Structure of a Flower Carpels are female structures composed of the stigma and ovary. Inside the ovary are the ovules which carry the developing egg and supporting cells.

48 Slide 48 / The male organ of the flower is the: A B C D style stamen carpel sepal

49 Slide 49 / In a typical flower, the parts that play the main role attracting animal-pollinators are the: A B C D petals fruits stigmas sepals

50 Slide 50 / The outer surface of a rosebud, before it opens up into bloom, consists of the: A B C D petals stamen ovary sepals

51 Slide 51 / In this picture of a lily, the arrow is pointing to the: A B C D stamen petal sepal stigma

52 Slide 52 / Review: look at photo and determine what type of angiosperm this flower is. A B C D monocot dicot vegetative fertilized How did you determine that?

53 Slide 53 / 86 Fertilization The development of pollen and ovules culminates in fertilization. All seed plants alternate between a diploid sporophyte generation that produce spores by meiosis and haploid gametophyte generation that produces gametes by mitosis. The gametes unite by fertilization to form a diploid zygote which is the first cell of the next sporophyte generation.

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55 Slide 55 / 86 The male gametophyte is the two-celled pollen grain. It undergoes meiosis in the anther and develops into spores. Each spore then develops mitotically to produce two haploid cells, a tube cell, and a generative cell. The outer wall of the pollen grain is thick and resistant to damage. Male Gametophytes

56 Slide 56 / Which flower part produces male gametophytes? A B C D carpels anthers sepals stigmas

57 Slide 57 / 86 Female Gametophytes The female gametophyte develops inside the ovule. One central cell undergoes meiosis and develops into a spore.

58 Slide 58 / 86 Female Gametophytes The nucleus in the spore divides (through mitosis) and forms the embryo sac. This is the female gametophyte. The embryo sac contains a large cell with two haploid nuclei. The specialized ovary tissue at the base of the carpel also houses a haploid egg.

59 Slide 59 / In the flowering plant, eggs are produced in the: A B C D stamens sepals ovules stigma

60 Slide 60 / 86 Pollination Pollen is usually wind or animal dispersed.

61 Slide 61 / 86 Pollen Germination Pollination occurs when the pollen from one flower is delivered to the stigma of another flower. After pollination, the grain germinates and a tube cell grows in the pollen tube downward toward the stigma and ovary. The generative cell divides (through mitosis) and forms two sperm. Once the tube reaches the ovule, it releases both sperm. TED Talks: "The hidden beauty of pollination", Louie Schwartzberg (07:40)

62 Slide 62 / 86 Double Fertilization Fertilization occurs in the ovule. One sperm fertilizes the egg forming a zygote (2n, diploid) which develops into the plant embryo. The other sperm fuses with the 2 central nuclei in the ovule and forms a triploid (3n) nucleus which develops into the endosperm tissue which nourishes the embryo in the seed.

63 Slide 63 / In angiosperms, the process of ensures that the endosperm will develop only in ovules containing a fertilized egg. A B C D cytogenesis meiosis mitosis double fertilization

64 Slide 64 / 86 REVIEW Drag the names to label the Flower carpel anther filament style ovary stigma stamen sepal petal ovule

65 Slide 65 / 86 Ovule develops into a seed Within the ovule, the diploid zygote divides, developing into the embryo. With the first division, one cell becomes the embryo, the other cell becomes a thread that forces the embryo into the endosperm. Near the end of maturation, the seed loses its water and develops a hardened seed coat.

66 Slide 66 / 86 Seed Dormancy Some seeds develop only to a point and then further development is suspended. The purpose of this is to allow time for dispersal. Seasonal conditions also play a role in seed dormancy, with the plant only continuing its maturation when conditions are right. An example of this is chemical dormancy, wherein a seed contains substances (often hormones) to keep the seed dormant for a period. Once these chemicals are washed away (for example by snow melt or spring rains ) the seed can germinate.

67 Slide 67 / 86 Monocot and Dicot Seed Differences Remember that seeds of dicots have 2 cotyledons which absorb endosperm nutrients and take over the role of nourishment. The seed of a monocot is actually a fruit with one seed inside. Corn seeds (the kernels) consist of a protective sheath, the embryonic root and shoot, and a large endosperm. dicot monocot

68 Slide 68 / 86 Ovary develops into a fruit The ovary of a flower changes into a fruit with the release of hormones following fertilization. The fruit houses and protects the seed, as well as aiding with the dispersal.

69 Slide 69 / 86 Pod Formation There are 3 steps to pod formation in a plant 1. pollination takes place 2. petals drop from the flower and ovaries start to grow 3. ovaries form the pod (or fruit)

70 Slide 70 / 86 Variations in Fruit Fruits are very varied in organization How many ovules, how many ovaries, how many carpels, how many flowers are involved and how the fruit is dispersed all account for the variations in fruits.

71 Slide 71 / 86 Types of fruit A peach is an example of a simple fruit. A raspberry is an example of an aggregate fruit. A pineapple is an example of a multiple fruit, one which develops from many united flowers.

72 Slide 72 / Flowers bear seeds in protective areas called: A B C D cones ovaries germination chambers sepals

73 Slide 73 / In the fully mature ovary, the vessel that houses the seed is the: A B C D ovule seed fruit cotyledon

74 Slide 74 / 86 Dicot seed germination In dicots, the root emerges first, followed by young seeds which exit the seed in a hooked shape that protects the meristem. Once the shoot exits the soil, light stimulates the shoot to straighten and the first leaves develop and begin photosynthesis. The cotyledons remain in the soil and decompose. EbE

75 Slide 75 / Which of these structures is first to emerge from a germinating dicot seed? A B C D root hook shoot cotyledon root hair

76 Slide 76 / 86 Monocot seed germination In monocots, the root emerges first, followed by shoots that do not develop into a hook. The shoots are protected by the abrasive soil by a sheath that surrounds them until they break through the surface. The cotyledon remains in the soil and decomposes. MGOA

77 Slide 77 / What eventually happens to the cotyledons of monocots and dicots? A B C D provide strength to the plant they form the leaves they remain in the soil and decompose they form the next ovule in the plant

78 Slide 78 / 86 Asexual Reproduction - cloning Vegetative propagation is the production of offspring from a single parent. The offspring are called clones and are genetically identical to the parent.

79 Slide 79 / 86 Asexual Reproduction - fragmenting Asexual reproduction often involves fragmentation into separate parts, each part developing into a new plant. A garlic bulb is an underground stem that will fragment into cloves, each developing into a new plant.

80 Slide 80 / 86 Advantage to fragmenting The advantage for this is each offspring is well suited to its immediate environment. Fragmented offspring are less fragile than seedlings.

81 Slide 81 / Genetically identical organisms which result from asexual reproduction are called: A B C D clones seeds twins meristems

82 Slide 82 / Which plant part commonly contributes to asexual reproduction? A B C D fruits shoots roots stems

83 Slide 83 / 86 Modern Agriculture Many ornamental trees are propagated through asexual reproduction by leaf and stem cuttings Propagation can also be done genetically through engineered plants (called GMOs - Genetically Modified Organisms) The disadvantage to this is the crop plants which come from cloning have low levels of genetic diversity and they are easily devastated by disease.

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85 Slide 85 / Which of the following shows the disadvantage to cloning as a propagation technique? A B C D its expensive its time consuming with slow results the plants can be easily wiped out by disease it requires a lot of farming space

86 Slide 86 / Foreign genes can be inserted into a plant cell and then cultured to produce: A B C D seeds genetically modified plants clones of the original plant plants that never die