Seedless Plants Ch12.2 7th Pdf

Seedless Plants Chapter 12 Section 2

Objectives: • List 3 nonvascular plants and 3 seedless plants • Explain how seedless plants are important to the environment • Describe the relationship between seedless vascular plants and coal

Is that a fact!! • Photographers (in the old days) created an explosive flash of light with powder. • The powder contained spores from club mosses (seedless vascular plants)

2 Groups of Plants That Do Not Make Seeds: • Nonvascular plants: mosses, liverworts, and hornworts • Vascular plants: ferns, horsetails, and club mosses

1. Nonvascular Plants: • Are small • Grow on soil, bark of trees, and rocks • Live in places that are damp • Do not have true stems, roots, or leaves

Mosses • Live together in large groups • Cover soil or rocks with a “mat”

• Have leafy stalks and rhizoids (root-like structure that holds these plants in place) • Rhizoids help the plants get water & nutrients • 2 stages to their life cycle (sporophyte/gametophyte)

Mosses -

http://www.science-art.com/gallery/47/47_6292006204817.jpg

Liverworts & Hornworts • Also are small • Live in damp places

• Similar life cycle: ▫ Gametophytes of liverworts can be leafy & mosslike or broad & flattened ▫ Gametophytes of hornworts are broad and flattened ▫ Both have rhizoids

Liverworts & Hornworts -

http://www.biology-blog.com/images/blogs/10-2006/plants-cycle-561.jpg

The Importance of Nonvascular Plants • Usually the 1st plants to live in a new environment (ex: newly exposed rock) • They form a thin layer of soil after they die (reduces soil erosion) • Animals eat or nest in them (habitat, food) • Peat mosses: useful to humans (fuel, potting soil)

2. Seedless Vascular Plants: • Larger than nonvascular plants • Include ferns, horsetails, and club mosses • Have specialized vascular tissue

Ferns • Grow in a variety of places (cold to warm) • Small or large • Rhizome: an underground stem from which new leaves and roots grow • Leaves: fronds coil (fiddleheads)

Ferns • Sporophyte: leafy fern • Gametophyte: tiny; about the size of your fingernail (green and flat – shaped like a heart)

http://botit.botany.wisc.edu/images/130/Ferns/Sporophyte_images/Fern_labeled_MC_.jpg

Ferns – life cycle

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Horsetails & Club Mosses • Horsetails: ▫ Grow in wet marshy places ▫ Stems are hollow and contain silica (gritty texture) – scouring rushes ▫ Similar life cycles to ferns

• Club Mosses: ▫ Grow in woodlands ▫ Not actually mosses – have vascular tissue ▫ Life cycle similar to ferns

Horsetails -

http://www.sdnhm.org/valentien/plantportraits/samples/03-35_horsetail250x400_ol.jpg

Club Mosses -

http://www.uwsp.edu/biology/courses/botlab/images/Lab22Ferns/22IB1a.JPG

Importance of Seedless Vascular Plants: • • • • • •

Help form soil Help prevent soil erosion Formation of communities Popular house plants Some are edible Shampoos, dietary supplements, skin-care products… • Remains of ancient seedless vascular plants formed coal

Quick Quiz: • What is the difference between a rhizoid and a rhizome? • Describe the environmental importance of mosses, liverworts, and hornworts.