1	How plants colonized the land
2	Land Plants evolved from green algae Charophyceans – Extant Chara sp.
3	Evidence Rose-shaped enzyme complexes for cellulose synthesis Peroxisome enzymes (minimization of photorespiration) Structure of flagellated sperm Formation of a phragmoplast (Cell wall formation during mitosis)
4	Plant Clades
5	Alternation of Generations The life cycles of all plants include a haploid Gametophyte generation and a diploid Sporophyte generation. Gametophytes produce gametangia which produce the gametes by mitosis. Antheridia - sperm Archegonia - eggs Sporophytes produce sporangia which produce spores by meiosis
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7	"Dependence of an embryo on..." Dependence of an embryo on female parent (gametophyte)
8	"Walled spores produced in a..." Walled spores produced in a sporangium
9	"Multicellular Gametangia" Multicellular Gametangia Moss archegonia Moss antheridia
10	Derived Traits of Land Plants Apical Meristems
11	"Plant Evolution" Plant Evolution
12	"We will examine three representative..." We will examine three representative groups of land plants Bryophytes (The Mosses) Pterophytes (The Ferns) Angiosperms (Flowering Plants)
13	Phylum: Bryophyta Mosses lack internal water transport tissue (vascular tissue) They are primary producers, but make up a relatively small portion of most ecosystems. They often act as colonizers, being the first plants into new habitats
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15	Moss Growth Habit Moss plants grow in clumps. The clump acts like a sponge holding water.
16	Moss Organs Leaves - photosynthesis Stem - support Rhizoids - anchorage
17	Moss Reproduction Alternation of Generations The alternation between a multicellular haploid “gametophyte” generation and a diploid “sporophyte” generation.
18	Moss Gametophytes
19	Male Antheridia The antheridia are located at the top of the male gametophyte
20	Moss Archegonia The archegonia are located at the top of the female gametophyte
21	Moss Life cycle
22	Moss Sporophyte The zygote develops into the multicellular sporophyte. The sporophyte remains attached atop the female gametophyte
23	Moss Capsule Meiosis occurs in the capsule to produce the haploid spores
24	Sporophyte capsule and caliptera
25	Protonema Moss spores disperse in the wind and germinate into protonema
26	"From the protonema grow young..." From the protonema grow young leafy gametophytes
27	Moss life cycle
28	Limitations of the Moss Lack of vascular tissue Need for free water for sperm transfer Vulnerable protonema stage
29	Sphagnum sp. (Peat Moss) Peat Bogs – Harvested for fuel.
30	People of the Bog
31	Origin of Vascular Plants The forerunners of the modern vascular plants date back about 420 million years.
32	Vascular plants Ferns and other seedless vascular plants formed the first forests. Forests of the Carboniferous period 350-300 million of years ago.
33	"The evolution of land plants..." The evolution of land plants has favored a dominant sporophyte generation.
34	Vascular Tissue Xylem – Tracheids (later vessels) Cells are dead at maturity Transports water and dissolved minerals upwards through the plants Phloem – Sieve tubes Cells are alive but are “anucleate” Transports water and organic molecules (sugars) upward or downwards through the plants.
35	Xylem – Tracheids (later vessels)
36	Phloem – Sieve tubes
37	"Evolution of leaves" Evolution of leaves
38	Spores and Sporangia Homosporous spore production One type of sporangia, single spores type, one “bisexual” gametophyte generation, antheridia makes sperm, archegonia makes eggs. Heterosporous spore production Megasporangia, makes megaspores, female gametophyte, archegonia, egg. Microsporangia, makes microspores, male gametophyte, antheridia, sperm.
39	"Phylum" Phylum: Lycophyta
40	"Phylum" Phylum: Pteridophyta
41	Fern Life cycle
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43	"Gametophyte generation" Gametophyte generation
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45	New sporophytes
46	Fern Life Cycle