1、The Plant Kingdom: Flowering Plants,Chapter 25,LEARNING OBJECTIVE 1,Summarize the features that distinguish flowering plants from gymnosperms,KEY TERMS,ANGIOSPERM Traditional name for flowering plants A large, diverse phylum of plants that form flowers for sexual reproduction and produce seeds enclo
2、sed in fruits,Flowering Plants,Like gymnosperms: Flowering plants have vascular tissues and produce seeds Unlike gymnosperms: Ovules of flowering plants are enclosed within an ovary,KEY TERMS,OVULE Structure in the ovary that contains a female gametophyte and develops into a seed after fertilization
3、 OVARY Base of a carpel or fused carpels that contains ovules and develops into a fruit after fertilization,Orange Fruit Development,LEARNING OBJECTIVE 2,Describe the ecological and economic significance of the flowering plants,Ecology and Economy,Our survival as a species depends on flowering plant
4、s Major food cropsProducts Cork, rubber, tobacco, coffee, chocolate, aromatic oils for perfumes Valuable lumber Fibers and medicines,Economic Botany,Subdiscipline of botany that deals with plants of economic importance Most of these are flowering plants,LEARNING OBJECTIVE 3,Distinguish between monoc
5、ots and eudicots, the two largest classes of flowering plantsGive specific examples of each class,KEY TERMS,COTYLEDON The seed leaf of a plant embryo, which may contain food stored for germination,KEY TERMS,MONOCOT One of two main classes of flowering plants; monocot seeds contain a single cotyledon
6、 Monocots have floral parts in threes Monocots include grasses, orchids, irises, onions, lilies, palms,KEY TERMS,EUDICOT One of two main classes of flowering plants; eudicot seeds contain two cotyledons Eudicots have floral parts in fours or fives Eudicots include oaks, roses, mustards, cacti, blueb
7、erries, sunflowers,Monocots and Eudicots,(a) Monocots, such as this nodding trillium (Trillium cernuum), have their floral parts in threes. Note the three green sepals, three white petals, six stamens, and three stigmas (the compound pistil consists of three fused carpels).,Stigmas of pistil,Anther
8、of stamen,Sepal,Petal,Fig. 25-2a, p. 488,(b) Most eudicots such as this Tacitus bellus have floral parts in fours or fives. Note the five petals, 10 stamens, and five separate pistils. Five sepals are also present but barely visible against the background.,Pistils,Anther of stamen,Petal,Fig. 25-2b,
9、p. 488,LEARNING OBJECTIVE 4,Briefly explain the life cycle of a flowering plantDescribe double fertilization,Life Cycle,Flowering plants undergo an alternation of generations: Sporophyte generation is larger and nutritionally independent Gametophyte generation is reduced to only a few microscopic ce
10、lls,KEY TERMS,DOUBLE FERTILIZATION A process in the flowering plant life cycle in which there are two fertilizations One results in formation of a zygote Second results in formation of endosperm,KEY TERMS,ENDOSPERM The 3n nutritive tissue formed at some point in the development of all angiosperm see
11、ds,Life Cycle: Flowering Plants,Flower of mature sporophyte,Seedling,Fruit,Seed coat,Seed,Embryo,Zygote (2n),Endosperm (3n),Anther,Megasporangium (ovule),Megaspore mother cell,Ovary,DIPLOID (2n) SPOROPHYTE GENERATION,HAPLOID (n) GAMETOPHYTE GENERATION,Megaspore,Egg nucleus,Double fertilization,Two s
12、perm cells,Pollen tube,Polar nuclei,Embryo sac (mature female gametophyte),Developing pollen tube of mature male gametophyte,Pollination,Pollen grain (immature male gametophyte),Each microspore develops into a pollen grain,Microspore,Tetrad of microspores,Microspore mother cells within microsporangi
13、a,Meiosis,1,2,4,5,6,3,8,7,Fig. 25-3, p. 490,Pollen Grains,LEARNING OBJECTIVE 5,Discuss some of the evolutionary adaptations of flowering plants,Adaptations of Flowering Plants 1,Reproduce sexually by forming flowersForm seeds within fruits after double fertilization,Adaptations of Flowering Plants 2
14、,Have efficient water-conducting vessel elements in xylem and carbohydrate-conducting sieve-tube elements in phloemHave pollen grains transported by wind, water, insects, other animals,KEY TERMS,APOMIXIS A type of reproduction in which fruits and seeds are formed asexually,Adaptability of Flowering
15、Plants,LEARNING OBJECTIVE 6,Trace the evolution of flowering plants from gymnosperms,Evolution of Flowering Plants,Probably descended from ancient gymnosperms with specialized features leaves with broad, expanded blades and closed carpelsProbably arose only once,Drimys piperita Carpel,(a) The carpel
16、 resembles a folded leaf in which the ovules borne on its upper surface are enclosed.,(b) A cross section of the carpel, cut along the dashed line in (a).,Stigma,Style,Ovary,Ovules,Stigma,Fused margin,Carpel,Fig. 25-6, p. 493,Fossil Angiosperms,(a) The oldest known fossil angiosperm. This fossil of
17、the extinct plant Archaefructus shows a carpel-bearing stem. It was discovered in northeastern China and is about 125 million years old.,(b) The fossilized flower of the extinct plant Archaeanthus linnenbergeri, which lived about 100 mya. The scars on the reproductive axis (receptacle) may show wher
18、e stamens, petals, and sepals were originally attached but abscised (fell off). Many spirally arranged pistils were still attached at the time this flower was fossilized.,Ovule,Carpel,Scars on reproductive axis,Pistils,Fig. 25-7, p. 494,Evolution of Flowering Plants,Basal Angiosperms,Core Angiosperm
19、s,Evolution of vessel elements,Evolution of flowering plants,(a) One hypothesis of relationships among the flowering plants, based on fossil and molecular evidence. Amborella, water lilies, and star anise are living plants whose ancestors apparently branched off the angiosperm family tree early. The
20、se early groups were followed by the magnoliids, the monocot branch, and the eudicots.,Amborella,Water lilies,Star anise,Magnoliids,Monocots,Eudicots,Fig. 25-8, p. 495,LEARNING OBJECTIVE 7,Distinguish between basal angiosperms and core angiosperms,KEY TERMS,BASAL ANGIOSPERM One of three groups of an
21、giosperms thought to be ancestral to all other flowering plants CORE ANGIOSPERM Group including most angiosperm species Divided into three subgroups: magnoliids, monocots, and eudicots,KEY TERMS,MAGNOLIID One of the groups of flowering plants Core angiosperms once classified as “dicots,” but molecul
22、ar evidence indicates they are neither eudicots nor monocots Includes species in magnolia, laurel, and black pepper families, several related families,LEARNING OBJECTIVE 8,Briefly describe the distinguishing characteristics and give an example or two of each of the following flowering plant families
23、: magnolia, walnut, cactus, mustard, rose, pea, potato, pumpkin, sunflower, grass, orchid, and agave,Flowering Plant Families 1,More than 300 families Magnolia family Important ornamentals and source of timber Examples: southern magnolia, tuliptree,Magnolia Family,Fig. 25-9, p. 497,Flowering Plant F
24、amilies 2,Walnut family Provides nuts for food, wood for furniture Examples: English walnut, black walnut, pecanCactus family Important as ornamentals Examples: prickly pear, Christmas cactus,Walnut Family,(a) The pinnately compound leaves and green fruits of black walnut (Juglans nigra) make the tr
25、ee easy to recognize.,Young tree,Compound leaf,Catkin of male flowers,Fruit (a drupe),Fruit with husk removed to show hard stone,Female flowers,Fig. 25-10a, p. 498,Fig. 25-10b, p. 498,Fig. 25-10c, p. 498,Cactus Family,(c) Cactus flowers contain numerous sepals, petals, and stamens. The compound pist
26、il consists of two to many fused carpels. In this photo of a prickly pear cactus (Opuntia humifusa), the petals, stamens, and stigma are evident.,Stamens,Petals,Stigma,Fig. 25-11c, p. 499,Flowering Plant Families 3,Mustard family Many important food crops Examples: cabbage, broccoli, cauliflower, tu
27、rnip, mustardRose family Commercially important fruits and ornamentals Examples: apple, pear, plum, cherry, apricot, peach, strawberry, raspberry, rose,Mustard Family,(a) A typical mustard flower, showing the four petals arranged in the shape of a cross.,Petal,Pistil,Sepal,Stamen,Fig. 25-12a, p. 501
28、,Mustard Family,Mustard Family,Mustard Family,Rose Family,Rose Family,Rose Family,Flowering Plant Families 4,Pea family Important food crops Examples: garden pea, chick pea, green bean, soybean, lima bean, peanut, red clover, alfalfa,Pea Family,(a) Part of a common bean (Phaseolus vulgaris) plant, s
29、howing flowers and developing fruits.,Remnants of sepals (and sometimes petals and stamens),Compound leaf (three leaflets),Young fruit,Pod (fruit),Seeds,(c) The bean fruit, a legume, is opened to show the seeds.,Remnants of stigma and style,(b) Close-up of a bean flower, showing its irregular coroll
30、a shape.,Keel (two fused petals),Wing,Banner,Sepal,Corolla,Fig. 25-14a-c, p. 503,Pea Family,Pea Family,Flowering Plant Families 5,Potato family Important food crops and chemicals used as drugs Examples: potato, tomato, green pepper, eggplant, petunia, deadly nightshade (belladonna),Potato Family,Flo
31、wering Plant Families 6,Pumpkin family Food crops Examples: pumpkins, melons, squashes, cucumbers, cantaloupe, honeydew, muskmelon, cucumber, watermelon,Pumpkin Family,(a) Cutaway view of a female squash flower. Note the inferior ovary located beneath the point of attachment of the sepals and petals
32、.,Ovary,Style,Stigma,Petals fused into bell shape,Fig. 25-16a, p. 505,Pumpkin Family,(b) Cutaway view of a male squash flower. Note the united anthers.,Anthers,Fig. 25-16b, p. 505,Pumpkin Family,Flowering Plant Families 7,Sunflower family One of the largest families of flowering plants Examples: chr
33、ysanthemums, marigolds, sunflowers, daisies, and some food plants such as lettuce, globe artichokes,Sunflower Family,a) Head of a sunflower (Helianthus annuus).,Disc floret,Ray floret,Fig. 25-17a, p. 506,(d) Bisexual disc floret.,(c) Female ray floret.,Ovary,Corolla,Anther,Stigmas,Disc floret,Ray fl
34、oret,Fig. 25-17cd, p. 506,Flowering Plant Families 8,Grass family Most important family of flowering plants from the human standpoint Examples: rice, wheat, corn, oats, barley, rye, sugarcane, bamboo,Grass Family,(a) The growth habit of a representative grass plant. Grass flowers, which are wind pol
35、linated, are highly modified. Note, for example, the long, feathery stigmas, adapted to efficiently catch wind-borne pollen.,Fibrous root system,Stolon,Rhizome,Sheath,Blade,Inflorescence,Lemma,Reduced petals,Ovary,Feathery stigma,Filament,Palea,Anther,Fig. 25-18a, p. 507,Flowering Plant Families 9,O
36、rchid family One of the largest families of flowering plants; contains a greater variety of flowers than any other family Example: the vanilla orchid Agave family Best known for ornamentals Examples: century plant, sisal hemp, bowstring hemp,Orchid Family,(a) The moth orchid (Phalaenopsis hybrid) ha
37、s photosynthetic aerial roots.,Aerial roots,Fig. 25-19a, p. 509,(b) A Cymbidium hybrid has pseudobulbs that function as storage organs.,Pseudobulbs,Fig. 25-19b, p. 509,(c) Orchid flowers, such as Dendrobium, are distinctive in that the third petal forms a lip.,Lip (modified petal),Sepal,Petal,Fig. 25-19c, p. 509,Agave Family,Animation: Monocot Life Cycle,CLICK TO PLAY,
