Lecture Chapter 29 2 16 12 Bryophyte sporophytes The life cycle of a moss Figure 29 8 Ecological and economic importance of mosses Seedless vascular plants Vascular plants began to evolve during the Carboniferous period 300 60 mya The life cycle of a fern Figure 29 Phylum lycophyta club mosses spike mosses and quillworts Are relics from a far more eminent past Are small herbaceous plants Phylum Pterophyta ferns horsetails and whisk ferns and relatives Ferns are most diverse seedless vascular plants The significance of seedless vascular plants The ancestors of modern lycophytes horsetails and ferns grew to great heights during the Carboniferous forming the first forests You should know Describe four shared characteristics and four distinct characteristics between charophytes and land plants Distinguish between the phylum Bryophyta and bryophytes Diagram and label the life cycle of a bryophyte Explain why most bryophytes grow close to the ground and are restricted to periodically moist environments Describe three traits that characterize modern vascular plants and explain how these traits have contributed to success on land Explain how vascular plants differ from bryophytes Distinguish between the following pairs of terms microphyll and megaphyll homosporous and Heterosporous Diagram and label the life cycle of a seedless vascular plant Chapter 30 plant diversity II the evolution of seed plants Overview transforming the world Seeds changed the course of plant evolution enabling their bearers to become the dominant producers in the most terrestrial ecosystems Figure 30 2 Ovules and production of eggs An ovule consists of a megasporangium megaspore and one or more protective integuments The evolutionary advantage of seeds Seeds provide some evolutionary advantages over spores They may remain dormant for days to years until conditions are favorable for germination They may be transported long distances by wind or animals 30 2 gymnosperms bear naked seeds typically on cones Gymnosperms appear early in the fossil record 360 mya and dominated the Mesozoic terrestrial ecosystems Exploring gymnosperm diversity Lecture Chapter 30 plant diversity II 2 21 12 Fruits are classified into several types Depending on their developmental origin Evolutionary links between angiosperms and animals Pollination of flowers by animals and transport of seeds by animals Are 2 important relationships in terrestrial ecosystems Chapter 38 plant reproduction The embryo and its food supply are enclosed by a hard protective seed coat In a eudicot the embryo consists of the hypocotyl radicle and thick cotyledons The embryo of the monocot has a single cotyledon a coleoptile and a coleorhiza Eudicot seed germination Figure Monocot seed germination The coleoptile pushes upward through the soil and into the air Lecture chapter 30 plant diversity II 2 23 12 Mechanisms of asexual reproduction In some species the root system of a single parent gives rise to many adventitious shoots that become separate shot systems Human welfare depends greatly on seed plants Table 30 1 Five derived traits of seed plants Table You should know Explain why pollen grains were an important adaptation for successful reproduction on land List and distinguish among the four phyla of gymnosperms Describe the life history of a pine indicate which structures are part of the gametophyte generation and which are part of the sporophyte generation Identify and describe the function of the following floral structures sepals petals stamens carpels filament anther stigma style ovary and ovule Explain how fruits may be adapted to disperse seeds Diagram the generalized life cycle of an angiosperm indicate which structures are part of the gametophyte generation and which are part of the sporophyte generation Describe the current threat to plant diversity caused by human population growth Chapter 35 and 36 The 3 basic plant organs roots stem and leaves 3 basic organs evolved roots stem and leaves Roots The absorption of water and minerals occurs near the root tips where vast numbers of tiny root hairs increase the surface area of the root Many plants have modified roots Figure 35 4 Many plants have modified stems Figure Leaves In classifying angiosperms taxonomists may use leaf morphology as a criterion Figure 35 6 Modified leaves serve various functions Figure The 3 tissue systems dermal vascular and ground Each plant organ has dermal vascular and ground tissues Common types of plant cells Parenchyma Thin flexible walls Carry out synthesis and storage of organic compounds cells alive at maturity Collenchyma Thicker cell walls primarily at corners Gives flexible support to growing plant cells alive Sclerenchyma Have thick 2 cell walls with lignin Cells dead at maturity Gives strong support consists of schlereids and fibers Water conducting cells of the xylem and sugar conducting cells of the phloem Figure 35 10 An overview of primary and secondary growth Figure 35 10 Lecture chapter 35 and 36 2 28 12 Primary growth of roots The root tip is covered by a root cap which protects the delicate apical meristem as the root pushes through soil during primary growth Organization of primary tissues in young roots Figure Lateral roots arise from within the pericycle the outermost cell layer in the vascular cylinder Primary growth of shoots A shoot apical meristem Figure Tissue organization of stems In gymnosperms and most eudicots Figure Monocot stems Figure Tissue organization of leaves Leaf anatomy Figure 35 17 Secondary growth adds girth to stem and roots in woody plants Secondary growth occurs in stems and roots of woody plants but rarely in leaves The secondary plant body consists of the tissues produced by the vascular cambium and cork cambium The vascular cambium is a cylinder of meristematic cells one cell thick develops from parenchyma cells Primary and secondary growth of a stem Figure Cross section of secondary growth Tree rings Early wood secondary xylem with thinner cell walls and large diameter represents spring growth Late wood secondary xylem with thicker cells walls represents late summer fall growth before dormant period Viewed in transverse section the vascular cambium Figure 35 19 Figure 35 20 Transport on plants Figure 36 2 Cohesion and adhesion in the ascent of xylem sap Figure Stomata help regulate the rate of transpiration About 90 of water a plant losses Escapes through stomata Transpiration also results in evaporative cooling which can lower