Plants Part II

Vascular & Nonvascular Vascular –Made up of tube-like, elongated cells for transporting water, food, and other materials –Includes most of the plants you are familiar with: Trees, ferns, grasses, ivy, flowers, etc Nonvascular –Do not have the vascular tissues Mosses, hornworts, liverworts

Vascular & Nonvascular Photo property of Bengt Korling Photo property of c3po.barnesos.net

Photosynthesis 6H2O + 6CO > C6H12O6+ 6O2 –Light dependent reaction Convert light energy to chemical energy (ATP) –ATP is then used in the light independent reaction producing simple sugars The Calvin Cycle –Converts Carbon Dioxide into simple sugars

Factors Affecting Photosynthesis Light Intensity Carbon Dioxide Concentration Temperature –Enzymes work best at specific temperatures

Phloem Tissues Sieve Tube Cells and Companion Cells Purves et al., Life: The Science of Biology, 4th Edition

Xylem Tissues Tracheids and vessel elements Dixon, & Joly (1894)

Root Types Taproots –Single thick structures with smaller branching roots –Accumulate and store food –Examples: carrots and beets Fibrous roots –Many small branching roots

Taproots and Fibrous Roots Asa Gray, The Elements of Botany for Beginners and for Schools

Woody Stems Cork, Phloem, Vascular Cambium, Xylem Composed mainly of dead xylem cells Secondary Growth (via lateral meristem) occurs in the vascular cambium Bark is composed of Phloem cells and cork cambium

Woody Stems

Flowers and Reproduction Courtesy of

Pollination

Monocots & Dicots Courtesy of Cotyledon: embryonic seed leaf

What is the purpose of fruits? Protection Dispersal Unknown original source

Divisions of Plants: Nonvascular Plants Bryophyta – The Mosses –Leaves are usually one cell thick –Rhizoids: like roots, help keep plant anchored Hepaticophyta – The Liverworts –Stems have flat thin leaves arranged in three rows –Also have rhizoids Antocerophyta – The Hornworts –Very similar to liverworts Courtesy of Eric Guinther Unknown source

Divisions of Plants: Vascular Plants Cycadophyta: The Cycads –One of the few seed plants that produce motile (moving) sperm Ginkgophyta: The Ginkgo –Only one living species: Ginkgo biloba –Not found in the wild –Also produce motile sperm –Soft seed-covering produces foul smell –Tolerates smog and pollution Gnetophyta: The Gnetophytes –Most also have separate male and female plants –Welwitschia may live 1000 years!

Divisions of Plants: Vascular Plants Courtesy of Courtesy of Unknown source

Divisions of Plants: Vascular Plants Coniferophyta –Needle-like or scale-like leaves –Most reproduce using cones –Mostly evergreen Anthophyta –Flowering plants –Form seeds enclosed in a fruit Courtesy of Courtesy of

Annuals, Biennials, and Perennials Annuals –Live only for one year or less Biennials –Live two years Perennials –Live for several years