Monilophytes are monophyletic horsetails

Info icon This preview shows pages 12–15. Sign up to view the full content.

Monilophytes are monophyletic Horsetails → photosynthetic stems, no leaves Ferns dominate tracheophytes Seed plants Benefits of seeds Embryophytic Dispersal
Image of page 12

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Dormancy Most ferns are homosporous Seed plants = heterosporous Pine tree Male+female cones on same tree → diecious Sporophylls are born on comes Microsporangium, microspore, pollen grain(microgametophyte) Female gametophyte is enclosed w/ protective tissue → dependent on sporophyte for nutrition Megasporangium, megaspore, megagametophyte (¼ gametes survive) Reduction in size of gametophytes All heterosporous, allow dispersal, allow dormancy, sporophyte dominant Gymnosperms Naked seed Divided into four groups → monophyletic Cycads Ancient, very large, slow growing Motile sperm (largest sperm) Ginkgos One extant species Diecious Tolerate high pollution levels Motile sperm Females lost cones Seeds smell bad Gnetophytes Vessel cells, homoplasious to angiosperms Gnetum - tree form Welwitschia 2 leaves, diecious, longest leaves on plants Ephedra Most gnetophytes belong to ephedra → respiratory Conifers Microsporangia (2n) produce microspores Megasporangium- produces female spores → become nucellus(2n) Megaspore(n) Integument(2n)- part of sporophyte, opening called micropyle, allows entry of pollen for fertilization Pollen tube grows through micropyle Fertilization can take up to 15 months Angiosperms Life cycle
Image of page 13
Megaspore only goes through 3 mitotic divisions 7 celled embryo sack 8 nuclei Male gametophyte: 3 celled Each microspore divides into a tube cell and a generative cell The generative cell divides to form 2 sperm cells Both sperm cells fuse with parts of the female gametophyte Sperm & egg= zygote (2N) Sperm and polar nuclei = 3N endosperm Angiosperms have double fertilization 2N zygotes and 3N endosperm Angiosperms vs. gymnosperms Flowers Reduced cells in gametophyte Speed of pollen tube growth Double fertilization Triploid endosperm Archaefructus Extinct, darwin’s abominable mystery, 125 million years ago, no sepal or sepals Amborella trichopoda Only remaining species in genus Small shrub or tree, small flowers Functionally diecious Nymphaeales - water lilies Fully aquatic, no vessel cells Stomata on one side of leaves, extended leaf and flower stems Austrobaileyales - star anise and relatives Small groups, woody plants Chloranthaceae and Certaphellum High O 2 production, aquarium plants Magnoliidae Economically important, trimerous Broadleaves, branching veins Eudicots “True” dicots, 4-5merous Coffee, tomato, cocoa, venus fly trap Monocots Make up the majority of angiosperms, economically important, rice=endosperm Pollination Biotic Beetles
Image of page 14

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

Image of page 15
This is the end of the preview. Sign up to access the rest of the document.
  • Fall '18
  • jessica poulin
  • Evolution, Cellular differentiation

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern