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Plants without seeds Chapter 8, section 2
Key concepts What characteristics do the three groups of nonvascular plants share What characteristics do the three groups of seedless vascular plants share?
Introduction Imagine you are hiking in the forest. You see many ferns along the trail. You walk a little father and stop to rest near a stream. Here you see mosses everywhere=on the forest floor on rocks and along the banks of the stream. Although ferns and mosses look very different, they have something in common. They reproduce without forming seeds.
Nonvascular Plants Three major groups of nonvascular plants Mosses
Liverworts and hornworts They are low growing plants that live in moist areas where they can absorb water and other nutrients directly from their environment
Mosses Green, fuzzy in the gametophyte generation
Rhizoids anchor the moss and absorb water and nutrients from the soil
Liverworts Grow on a thick crust of moist rocks or soil along the sides of a stream
Hornworts Seldom found on tree trunks or rocks, live in moist soil, mixed in with grass plants
Seedless vascular plants
Among the plants were huge, tree-sized ferns as well as trees with branches that grew in a series of circles along the trunk. Other trees resembled giant sticks with leaves up to one meter long. When the leaves dropped off, they left diamond-shaped scars. These tall odd-looking trees were the ancestors of three groups of plants that are alive today-ferns-horsetails, and club mosses. They are seedless plants that have vascular tissue
Characteristics of seedless vascular plants
Do not produce seeds Reproduce by producing spores Vascular plants grow tall Strong cell walls providing strength and stability Need to grow in moist surroundings in order for gametophytes produce egg cells and sperm cells
Ferns Underground root system
Horsetails Long, coarse, needlelike branches grow in a circle around each joint Stems contains silica During colonial times, Americans used the plants to scrub their pots and pans
Club Mosses Club mosses have vascular tissue
Grow in moist woodlands and near streams
1. Which part of plant look like roots
2. Which parts look like true stems and leaves
Green stem like and leaf like structures
3. Why do scientists call these moss parts roots, stems and leaves?
They do not have transport tissue as true roots, stems and leaves do
4. How are mosses and other nonvascular plants limited by their lack of vascular tissue?
They do not grow very because they cannot transport water as far and as fast as is needed for a tall plant to survive
5. How are these plants similar to most larger plants today?
They have vascular tissue
6. What structures give these seedless plants strength and stability?
7. Why is moisture important for reproduction in seedless vascular plants?
Sperm must swim through water to the eggs
8. What advantage is the cuticle to the plant?
It helps prevent water loss from the plant
9. What two characteristics do mosses, liverworts, and hornworts share?
They are low growing and live in moist environments where they can absorb water and nutrients directly from their environment
10. What two characteristics do ferns horsetails and club mosses share?
Vascular tissue and the use of spores to reproduce
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