Bitki Çeşitliliği

Bitki olmadan yaşam düşünülemez 3 milyar yıl öncesinde büyük ölçüde karada yaşam yoktu 1.2 milyar yıl önce cyanobacteria 500 milyon yıl öce hayvan fungus ve bitki 290000 bitki çeşidi

Karasal bitkiler yeşil alglerden (Charophyta) köken almış Bitkiler de bazı yeşil, kırmızı,ve kahverengi algler gibi çok hücreli, ökaryot ve fotosentetik Selüloz H. çeperi (Dinoflagellat, yeşil ve kahverengi alg) Klorofil a ve b (Dinoflagellat ve Euglena)

Charophyta ve bitkilerin paylaştığı 4 özellik Selüloz üreten çember şeklinde yapı Peroksizom enzimleri Kamçılı sperm Fragmoplast oluşumu 30 nm

Genetik benzerlik Nuklear ve kloroplast DNA çalışmaları; bitki ve Charophyta bezerlik fazla Chara, a pond organism (a) 10 mm Coleochaete orbicularis, a disk- shaped charophycean (LM) (b) 40 µm Figure 29.3a, b

Bitki aleminin sınırları ??? Plantae Streptophyta Viridiplantae Red algae Chlorophytes Charophyceans Embryophytes Ancestral alga Figure 29.4

Bitkilerde türemiş özellik Apikal meristem Döl almaşı (çok hücreli bağımlı embrio) Sporangiumlarda üretilen çeperli sporlar Multisellular gametangium Bunlara ek olarak; Kutikül oluşumu, sekonder metabolit üretimi başlamış

Apical meristem ve döl almaşı APICAL MERISTEMS Apical meristem of shoot Developing leaves 100 µm Apical meristems of plant shoots and roots. The light micrographs are longitudinal sections at the tips of a shoot and root. Apical meristem of root Root Shoot Figure 29.5 Haploid multicellular organism (gametophyte) Mitosis Gametes Zygote Diploid multicellular organism (sporophyte) Alternation of generations: a generalized scheme MEIOSIS FERTILIZATION 2n n Spores ALTERNATION OF GENERATIONS Figure 29.5

Sporangiumlarda üretilen çeperli sporlar; multisellular gametangium, çok hücreli bağımlı embrio Spores WALLED SPORES PRODUCED IN SPORANGIA Sporangium Sporophyte and sporangium of Sphagnum (a moss) Longitudinal section of Sphagnum sporangium (LM) Sporophyte Gametophyte MULTICELLULAR GAMETANGIA Female gametophyte Archegonium with egg Archegonia and antheridia of Marchantia (a liverwort) Antheridium with sperm Male gametophyte MULTICELLULAR, DEPENDENT EMBRYOS Embryo Maternal tissue 2 µm Embryo and placental transfer cell of Marchantia 10 µm Figure 29.5 Wall ingrowths Placental transfer cell

Fosilleşmiş spor ve bitki dokusu 475-milyon yaşındaki taştan elde edilmis Fossilized spores. Unlike the spores of most living plants, which are single grains, these spores found in Oman are in groups of four (left; one hidden) and two (right). (a) Fossilized sporophyte tissue. The spores were embedded in tissue that appears to be from plants. (b) Figure 29.6 a, b

Günümüzde yaşayan önemli bitki grupları Table 29.1

Seedless vascular plants Karasal bitkiler iletim dokularının olup olmamasına göre sınıflandırılabilir Land plants Vascular plants Bryophytes (nonvascular plants) Seedless vascular plants Seed plants Mosses Liverworts Hornworts Charophyceans Gymnosperms Angiosperms Pterophyte (ferns, horsetails, whisk fern) Origin of seed plants (about 360 mya) Lycophytes (club mosses, spike mosses, quillworts) Origin of vascular plants (about 420 mya) Origin of land plants (about 475 mya) Ancestral green alga Figure 29.7

Bryofit (İletim Demetsiz Bitki) Yapraksı karayosunları ve iletim demetsiz diğer bitkilerin yaşam döngüsünde Gametofit faz baskındır Bryofitlerde 3 şube Liverworts (Hepatophyta) Hornworts (Anthocerophyta) Mosses (Bryophyta) (İletim demetli bitki grubuna en yakın)

Bryofit Gametofitleri Bütün bryofitlerde ; Haplod gametofitler, sporofitlere oranla daha büyük ve daha uzun süre yaşar Mature sporophytes Young sporophyte Male gametophyte Raindrop Sperm Key Haploid (n) Diploid (2n) Antheridia Female gametophyte Egg Archegonia FERTILIZATION (within archegonium) Zygote Archegonium Embryo Female gametophytes Gametophore Foot Capsule (sporangium) Seta Peristome Spores Protonemata “Bud” MEIOSIS Sporangium Calyptra Capsule with peristome (LM) Rhizoid Mature sporophytes Spores develop into threadlike protonemata. 1 The haploid protonemata produce “buds” that grow into gametophytes. 2 Most mosses have separate male and female gametophytes, with antheridia and archegonia, respectively. 3 A sperm swims through a film of moisture to an archegonium and fertilizes the egg. 4 Meiosis occurs and haploid spores develop in the sporangium of the sporophyte. When the sporangium lid pops off, the peristome “teeth” regulate gradual release of the spores. 8 The sporophyte grows a long stalk, or seta, that emerges from the archegonium. 6 The diploid zygote develops into a sporophyte embryo within the archegonium. 5 Attached by its foot, the sporophyte remains nutritionally dependent on the gametophyte. 7 Figure 29.8

Bryofit gametofit Bazı karayosunları Anteridyumda flagellalı sperm Arkegonyumda yumurta Bazı karayosunları Gövdenin orta kısmında iletim demetlerine sahip olabilir bu sayede vertikal uzayabilir

Hornwort ve karayosun sporofitleri stomaya sahip Bryofit Sporofitleri Bryophyte sporofit Arkegonyum üzerinde gelişir Küçük ve basit Ayak, sap ve sporangium (kapsül) içerir Hornwort ve karayosun sporofitleri stomaya sahip

Bryofit diversity Figure 29.9 LIVERWORTS (PHYLUM HEPATOPHYTA) HORNWORTS (PHYLUM ANTHOCEROPHYTA) MOSSES (PHYLUM BRYOPHYTA) Gametophore of female gametophyte Marchantia polymorpha, a “thalloid” liverwort Foot Sporangium Seta 500 µm Marchantia sporophyte (LM) Plagiochila deltoidea, a “leafy” liverwort An Anthoceros hornwort species Sporophyte Gametophyte Polytrichum commune, hairy-cap moss Figure 29.9

Tohumsuz Iletim Demetli Bitki (Fern, Eğrelti otu) Fern ve diğer tohumsuz iletim demetli bitkiler ormanların ilk halini olusturur Bağımsız ve dallanan sporofit Figure 29.11

Tohumsuz iletim demetli bitki sınıflandırması Lycophyta (Kibrit otu): club mosses, spike mosses, epifit Pterophyta: fern (eğrelti), atkuyruğu LYCOPHYTES (PHYLUM LYCOPHYTA) PTEROPHYTES (PHYLUM PTEROPHYTA) WHISK FERNS AND RELATIVES HORSETAILS FERNS Isoetes gunnii, a quillwort Selaginella apoda, a spike moss Diphasiastrum tristachyum, a club moss Strobili (clusters of sporophylls) Psilotum nudum, a whisk fern Equisetum arvense, field horsetail Vegetative stem Strobilus on fertile stem Athyrium filix-femina, lady fern Figure 29.14

Bryofitlerden farklı olarak Sporofit baskın Bryofitlerden farklı olarak Tohumsuz iletim demetli bitkilerin (fern) sporofit fazı daha baskın Gametofit narin, küçük, toprak yüzeyinde veya altında

The life cycle of a fern Figure 29.12 Sporangia release spores. Most fern species produce a single type of spore that gives rise to a bisexual gametophyte. 1 The fern spore develops into a small, photosynthetic gametophyte. 2 Although this illustration shows an egg and sperm from the same gametophyte, a variety of mechanisms promote cross-fertilization between gametophytes. 3 Key Haploid (n) Diploid (2n) Antheridium Spore Young gametophyte MEIOSIS Sporangium Archegonium Sperm Mature sporophyte Egg New sporophyte Zygote Sporangium FERTILIZATION Sorus On the underside of the sporophyte‘s reproductive leaves are spots called sori. Each sorus is a cluster of sporangia. 6 Fern sperm use flagella to swim from the antheridia to eggs in the archegonia. 4 Gametophyte Fiddlehead A zygote develops into a new sporophyte, and the young plant grows out from an archegonium of its parent, the gametophyte. 5 Figure 29.12

Ksilem ve Floem İletim demetli bitkilerdeki doku Xylem and phloem su ve mineral trakeid Phloem şeker, amino acid, ve diğer organic madde canlı hücre

Sporofil ve Spor Varyasyonu Sporangium tasıyan modifiye yaprak Cogu tohumsuz iletim demetli bitki (Fern, kibrit otu, Atkuyruğu) homospor, tek tip spor, biseksuel gametofit Tohumlu heterospor, iki cesit spor, erkek ve dişi gametofit

Tohumlu Bitkiler (İletim Demetli) Gimnosperm, Angiosperm İndirgenmiş gametofit polen ve ovulde korunur (Ebevyn sporofitte özel dokularca çevrili) Tohumlara ilave olarak, şu özellikler var İndirgenmis gametofit Heterospor Ovul Polen

Gametofit/sporofit ilişki Sporophyte (2n) Sporophyte (2n) Gametophyte (n) Gametophyte (n) Sporophyte dependent on gametophyte (mosses and other bryophytes). (a) Large sporophyte and small, independent gametophyte (ferns and other seedless vascular plants). (b) Microscopic female gametophytes (n) in ovulate cones (dependent) Microscopic female gametophytes (n) inside these parts of flowers (dependent) Microscopic male gametophytes (n) inside these parts of flowers (dependent) Microscopic male gametophytes (n) in pollen cones (dependent) Sporophyte (2n), the flowering plant (independent) Sporophyte (2n) (independent) Reduced gametophyte dependent on sporophyte (seed plants: gymnosperms and angiosperms). (c) Figure 30.2a–c

Ovul ve Yumurta üretimi Ovul içinde megasporangium, megaspore, ve koruyucu integumentler, yumurta (n) Figure 30.3a (a) Unfertilized ovule. In this sectional view through the ovule of a pine (a gymnosperm), a fleshy megasporangium is surrounded by a protective layer of tissue called an integument. (Angiosperms have two integuments.) Integument Spore wall Megasporangium (2n) Megaspore (n)

Pollen ve Sperm üretimi Mikrosporangium, microspor; pollen (n) Polinasyon Pollenin ovule transferi

Germination olursa 2 sperm taşıyan polen tüpü ovul içindeki dişi gametofite ulaşır Female gametophyte (n) Egg nucleus (n) Spore wall Male gametophyte (within germinating pollen grain) (n) Discharged sperm nucleus (n) Pollen grain (n) Micropyle (b) Fertilized ovule. A megaspore develops into a multicellular female gametophyte. The micropyle, the only opening through the integument, allows entry of a pollen grain. The pollen grain contains a male gametophyte, which develops a pollen tube that discharges sperm. Figure 30.3b

Tohumun evrimdeki avantajı Tüm ovulden oluşur Koruyucu doku, embriyo, besi doku Gymnosperm seed. Fertilization initiates the transformation of the ovule into a seed, which consists of a sporophyte embryo, a food supply, and a protective seed coat derived from the integument. (c) Seed coat (derived from Integument) Food supply (female gametophyte tissue) (n) Embryo (2n) (new sporophyte) Figure 30.3c

çıplak tohum (kozalak) en iyi örnek koniferler Sube Gimnosperm çıplak tohum (kozalak) en iyi örnek koniferler Sube Cycadophyta Gingkophyta Gnetophyta Coniferophyta

Figure 30.4 PHYLUM CYCADOPHYTA PHYLUM GINKGOPHYTA PHYLUM GNETOPHYTA Gnetum Ephedra Ovulate cones Welwitschia PHYLUM GNETOPHYTA PHYLUM CYCADOPHYTA PHYLUM GINKGOPHYTA Cycas revoluta Figure 30.4

Figure 30.4 Douglas fir Common juniper PHYLUM CYCADOPHYTA Pacific yew Common juniper Wollemia pine Bristlecone pine Sequoia PHYLUM CYCADOPHYTA Figure 30.4

İğne yapraklılıların yaşam döngüsü *sporofit baskın *fertilize olmuş ovülden tohum oluşumu *polenin ana rolü; spermi ovüle taşımak An ovulate cone scale has two ovules, each containing a mega- sporangium. Only one ovule is shown. 2 Figure 30.6 Ovule Megasporocyte (2n) Integument Longitudinal section of ovulate cone Ovulate cone Pollen Mature sporophyte (2n) pollen cone Microsporocytes grains (n) (containing male gametophytes) MEIOSIS Micropyle Germinating pollen grain Megasporangium Sporophyll Microsporangium Surviving megaspore (n) Archegonium Egg (n) Female gametophyte pollen grain (n) Discharged sperm nucleus (n) tube Egg nucleus (n) FERTILIZATION Seed coat (derived from parent sporophyte) (2n) Food reserves (gametophyte tissue) (n) Embryo (new sporophyte) Seeds on surface of ovulate scale Seedling Key Diploid (2n) Haploid (n) In most conifer species, each tree has both ovulate and pollen cones. 1 A pollen grain enters through the micropyle and germinates, forming a pollen tube that slowly digests through the megasporangium. 4 While the pollen tube develops, the megasporocyte (megaspore mother cell) undergoes meiosis, producing four haploid cells. One survives as a megaspore. 5 A pollen cone contains many microsporangia held in sporophylls. Each microsporangium contains microsporocytes (microspore mother cells). These undergo meiosis, giving rise to haploid microspores that develop into pollen grains. 3 The female gametophyte develops within the megaspore and contains two or three archegonia, each with an egg. 6 Fertilization usually occurs more than a year after pollination. All eggs may be fertilized, but usually only one zygote develops into an embryo. The ovule becomes a seed, consisting of an embryo, food supply, and seed coat. 8 By the time the eggs are mature, two sperm cells have developed in the pollen tube, which extends to the female gametophyte. Fertilization occurs when sperm and egg nuclei unite. 7

Angiosperm Angiospermler çiçek ve meyveye sahip (evrimsel adaptasyon için önemli) Çiçekli bitkiler olarak bilinir En yayın ve diverse olan grup Üreme organları çiçek ve meyve

Çiçek (Flower) Çiçek yapı Sepal Petal Stamen Carpels (pistil) Anther Filament Stigma Style Ovary Carpel Petal Receptacle Ovule Sepal Stamen Figure 30.7

Meyve (Fruit) Olgunlaşmış ovary Figure 30.8a–e (b) Ruby grapefruit, a fleshy fruit with a hard outer layer and soft inner layer of pericarp (a) Tomato, a fleshy fruit with soft outer and inner layers of pericarp (c) Nectarine, a fleshy fruit with a soft outer layer and hard inner layer (pit) of pericarp (e) Walnut, a dry fruit that remains closed at maturity (d) Milkweed, a dry fruit that splits open at maturity

Taşınma şekilleri Figure 30.9a–c (a) Wings enable maple fruits to be easily carried by the wind. (a) Seeds within berries and other edible fruits are often dispersed in animal feces. (b) The barbs of cockleburs facilitate seed dispersal by allowing the fruits to “hitchhike” on animals. (c) Figure 30.9a–c

Angiospermlerde yaşam döngüsü double fertilization; 2 sperm polen tüpü ile ovüldeki dişi gametofite girer bir sperm dişi gametofitteki yumurtayla, diğeri merkezde yer alan 2 nukleusla birleşir (endosperm) endosperm fotosetez aşamasına kadar (filiz) embriyoyu besler

Figure 30.10 Key Mature flower on sporophyte plant (2n) Ovule with megasporangium (2n) Female gametophyte (embryo sac) Nucleus of developing endosperm (3n) Discharged sperm nuclei (n) Pollen tube Male gametophyte (in pollen grain) Sperm Surviving megaspore (n) Microspore (n) Generative cell Tube cell Stigma Ovary MEIOSIS Megasporangium grains Egg Nucleus (n) Zygote (2n) Antipodal cells Polar nuclei Synergids Egg (n) Embryo (2n) Endosperm (food Supply) (3n) Seed coat (2n) Seed FERTILIZATION Haploid (n) Diploid (2n) Anther Style Microsporangium Microsporocytes (2n) Germinating Anthers contain microsporangia. Each microsporangium contains micro- sporocytes (microspore mother cells) that divide by meiosis, producing microspores. 1 Microspores form pollen grains (containing male gametophytes). The generative cell will divide to form two sperm. The tube cell will produce the pollen tube. 2 When a seed germinates, the embryo develops into a mature sporophyte. 7 In the megasporangium of each ovule, the megasporocyte divides by meiosis and produces four megaspores. The surviving megaspore in each ovule forms a female gametophyte (embryo sac). 3 The zygote develops into an embryo that is packaged along with food into a seed. (The fruit tissues surround- ing the seed are not shown). 6 After pollina- tion, eventually two sperm nuclei are discharged in each ovule. 4 Double fertilization occurs. One sperm fertilizes the egg, forming a zygote. The other sperm combines with the two polar nuclei to form the nucleus of the endosperm, which is triploid in this example. 5 Figure 30.10

Fosil Angiosperm Hem gelişömiş hemde primitiv özellik Figure 30.11a, b Carpel Stamen Archaefructus sinensis, a 125-million-year- old fossil. (a) Artist’s reconstruction of Archaefructus sinensis (b) 5 cm Figure 30.11a, b

Dog rose (Rosa canina), a wild rose Monokot ve dikot Orchid (Lemboglossum fossii) Monocot Characteristics Embryos Leaf venation Stems Roots Pollen Flowers Pollen grain with one opening Root system Usually fibrous (no main root) Vascular tissue scattered Veins usually parallel One cotyledon Two cotyledons netlike usually arranged in ring Taproot (main root) usually present three openings Zucchini (Cucurbita Pepo), female (left) and male flowers Pea (Lathyrus nervosus, Lord Anson’s blue pea), a legume Dog rose (Rosa canina), a wild rose Pygmy date palm (Phoenix roebelenii) Lily (Lilium “Enchant- ment”) Barley (Hordeum vulgare), a grass Anther Stigma California poppy (Eschscholzia californica) Pyrenean oak (Quercus pyrenaica) Floral organs usually in multiples of three Floral organs usually in multiples of four or five Filament Ovary Eudicot MONOCOTS EUDICOTS Figure 30.12