UT Arlington BIOL BIOL 3427 - ch20 (9 pages)

Previewing pages 1, 2, 3 of 9 page document View the full content.
View Full Document

ch20



Previewing pages 1, 2, 3 of actual document.

View the full content.
View Full Document
View Full Document

ch20

102 views


Pages:
9
School:
University of Texas at Arlington
Course:
Biol Biol 3427 - Plant Science
Plant Science Documents

Unformatted text preview:

BRYOPHYTES Chapter 20 ADAPTATIONS ENABLING THE MOVE TO LAND 1 A layer of sporopollenin protects charophytes from desiccation sporopollenin is found in the spore wall of land plants 2 Danger of desiccation required new adaptations transport tissue cuticle large compact multicellular body etc 3 Simultaneous evolution of cuticle and stomata with guard cells 4 Support against gravity 5 Reproduction became adapted to periods of moisture so sperms could swim 6 Gametes and spore mother cells became protected from dryness by layers of cells 7 Evolution of xylem and phloem to transport materials to and from different parts of the plant the atmosphere and the soil 8 Alternation of generations a characteristic life cycle Alternation of generation does not occur in the charophyceans This suggests that alternation of generation arose independently in land plants A life cycle characterized by a multicellular haploid gametophyte stage followed by a multicellular diploid sporophyte stage Multicellular dependent embryos The zygote is retained surrounded by tissues of the gametophyte The parental tissue provides the embryo with nutrients Placental transfer cells present in the embryo and sometimes in the gametophyte as well enhance the transfer of nutrients 9 Spores produced in sporangia haploid reproductive cells that become a multicellular haploid gametophyte by mitosis The multicellular sporangium contains sporocytes the cells that undergo meiosis to form spores 10 Plants are eukaryotic multicellular mostly autotrophic organisms with haploid diploid life cycles which retain embryo within female sex organ on parent plant the cell wall contains cellulose CHARACTERS OF NONVASCULAR PLANTS About 17 000 species worldwide divided into three Divisions Bryophyta the mosses Hepatophyta the liverworts and Anthocerophyta the hornworts Their life cycle is similar but the three groups may not be closely related The bryophytes may form a polyphyletic group Bryophyta refers to the phylum of



View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view ch20 and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view ch20 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?