Download presentation
Presentation is loading. Please wait.
Published byElwin Hicks Modified over 8 years ago
1
Chapter 29
2
500 mya plants and fungi moved from the land to the water All plants evolved from an aquatic green algae In Kingdom Plantae, there are 4 main subdivisions: Bryophytes, Seedless Vascular Plants (ch 29), Gymnosperms, and Angiosperms (ch 30)
3
Plants and algae share 4 key traits due to their evolutionary origins: Rose-shaped complexes for cellulose synthesis Peroxisome enzymes (minimize glucose loss) Structure of flagellated sperm Formation of a phragmoplast (helps form the cell plate during mitosis)
4
Plants (and not algae) have 5 traits that allowed them to move onto land: Apical Meristems Alternation of Generations Walled spores produced in sporangia Multicellular Gametangia Multicellular, Dependent Embryos
5
An apical meristem is a localized region of cell division at the tips of roots and shoots. Mitosis occurs rapidly here, so plants can optimize water and mineral collection from the soil and the atmosphere.
6
The life cycle of land plants alternates between a diploid multicellular organism (sporophyte) and a haploid multicellular organism (gametophyte).
7
Plant spores are haploid reproductive cells Through mitosis, they can develop into gametophytes The diploid sporophyte has multicellular organs called sporangia that produce plant spores Spores are formed from sporocytes (inside sporangia) that go through meiosis
8
Gametes are made in organs called gametangia Female gametangia are called archegonia Male gametangia are called antheridia
9
Zygotes undergo mitosis to become multicellular embryos called embryophytes, which stay inside the female parent’s tissues The embryo has special cells called placental transfer cells that enhance the transfer of nutrients from parent to embryo
10
Vascular tissue is made up of cells that transport water and nutrients throughout a plant. Vascular plants either are seedless (mosses, horsetails, and ferns) or have seeds (gymnosperms like pine trees, angiosperms like flowers) Non-vascular plants include liverworts, hornworts, and mosses
12
Bryophytes are non-vascular, seedless plants Liverworts Hornworts Mosses
13
Phylum Hepatophyta Gametophytes are shaped like livers Common in Northern Hemisphere tropical and subtropical regions
14
Phylum Anthocerophyta Sporophytes are shaped like blades of grass 5 cm high
15
Phylum Bryophyta Gametophytes look like carpets Sporophytes are elongated and visible to the naked eye
16
Gametophytes (the haploid stage) are larger and longer lived than sporophytes (the diploid stage) Germinating moss spores produce a protonema, a mass of green, branched, one- cell thick filaments. They absorb water and form buds that produce gametes called gametophores. The protonema and the gametophore make up the moss gametophyte.
17
Gametophytes are anchored by delicate rhizoids (long tubular single celled filaments).
18
Bryophytes sporophytes are green and photosynthetic, but remain attached to their parental gametophytes which give them sugar, amino acids, minerals and water. Sporophytes are simple and small, made up of a foot (absorbs nutrients), a seta (long stalk), and a sporangium (on top of the stalk, makes spores).
19
Ferns are vascular plants WITHOUT seeds They have swimming sperm and need moist environments Ferns have a life cycle with a dominant sporophyte
20
Xylem are tubes that conduct water and minerals in a plant Xylem is made up of tracheids, tube shaped cells that carry water Their cell walls are strengthened by ligin Phloem are tubes that conduct sugar in a plant
21
Roots are organs that anchor vascular plants and enable them to absorb water and nutrients from the soil Leaves are organs that increase the surface area of vascular plants, capturing more solar energy for photosynthesis
22
Sporophylls are leaves that bear sporangia (which make spores) A group of sporangia are called a sorus (sori), and are shaped like cones called strobili.
23
Seedless vascular plants, like ferns, lychophytes, and horsetails, formed the first forests These removed CO2 from the atmosphere and increased levels of oxygen, causing global cooling and glacier formation. These forests, after millions of years of decay, heat, and pressure, became coal (which now causes global warming).
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.