Reading Essentials for Biology Glencoe (794133), страница 56
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Underline a factabout each plant division.1. What are the highlightsof plant evolution?________________________________________________________________________Phylogeny is the evolutionary history of a species. Once plantsadapted to life on land, they were not finished adapting. Manygeological and climate changes have taken place since the firstplants evolved. Landmasses have moved from place to place overEarth’s surface. Climates have changed.
Bodies of water haveformed and then disappeared. Hundreds of thousands of plantspecies have evolved and many of them became extinct as conditions changed. As plant species evolved in this changing landscape, they kept many of their old characteristics and developednew ones.Botanists (scientists who study plants) use plant characteristics toclassify plants into divisions. Highlights of plant evolution include:1. origins of plants from green algae,2. the production of a waxy cuticle,3. the development of vascular tissue and roots, and4. the production of seeds.Producing seeds is one way to separate plants into two groups—non-seed plants and seed plants.________________________238Chapter 21READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Phylogeny of PlantsNameDateClassSection21.2Survey of the Plant Kingdom, continuedNon-seed PlantsNon-seed plants produce reproductive cells called spores.
Somenon-seed plants are vascular, and some are non-vascular. Thereare seven divisions within the non-seed plant group.What are hepaticophytes?Hepaticophytes (heh PAH tih koh fites) make up one division ofnon-seed plants. Hepaticophytes include plants commonly knownas liverworts. They are small plants with flattened bodies thatremind some people of the shape of an animal’s liver. Liverwortsare nonvascular plants. They grow only in moist environments.Because they are nonvascular, they move water and nutrientsthroughout the plant by osmosis and diffusion. Some studies suggest that liverworts may be the ancestors of all plants.2. What do studies suggestabout liverworts?________________________________________________________________________What are anthocerophytes?Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Anthocerophytes (an THOH ser oh fites) also are small, nonvascular plants that grow in damp, shady habitats.
They rely onosmosis and diffusion to transport nutrients. The sporophytes ofthese plants resemble the horns of an animal, giving the plants thecommon name of hornworts.What are bryophytes?Bryophytes (BRI uh fites) are commonly called mosses. Theyare nonvascular plants. However, some mosses have cells thattransport water and sugars. Moss plants are usually less than5 cm tall.
They have leaflike structures that are only one or twocells thick.What are psilophytes?Psilophytes, known as whisk ferns, are vascular plants. They areunique among vascular plants because they do not have roots orleaves. They consist of thin, green stems. Psilophytes are found intropical and subtropical environments. Only one genus of psilophytes can be found in the southern United States.READING ESSENTIALSChapter 21239NameDateClassSection21.2Survey of the Plant Kingdom, continuedWhat are lycophytes?Once lycophytes (LI koh fites) were 30 m tall and formed alarge part of the forests that existed during the Paleozoic Era.Lycophytes, the club mosses, are usually less than 25 cm high.Lycophytes are vascular plants that have stems, roots, and leaves.What are arthrophytes?Arthrophytes (AR throh fites), often called horsetails, are vascular plants.
They have hollow, jointed stems. Circling the stemare leaves that resemble scales. All modern horsetails are small,but their fossil relatives were the size of trees.What are pterophytes?Pterophytes (TER oh fites) are the most well-known and diversegroup of non-seed vascular plants. You know them as ferns. Fernswere abundant in forests of the Paleozoic and Mesozoic Eras.They have leaves called fronds that vary in length from 1 cm to500 cm.
The pterophytes are the only group in the non-seed vascular plants that have complex leaves.Seed Plants________________________Seed plants produce seeds. A seed consists of a plant embryoand a food supply covered by a hard protective coat. In dry conditions, seeds are better adapted for reproduction than spores.
Allseed plants have vascular tissues.________________________What are cycads?________________________Cycads (SI kuds) were abundant during the Mesozoic Era.Today there are about 100 species of cycads. They look like palmtrees, have scaly trunks, and come in various heights. Cycads produce male and female cones on separate trees. Cones are scalystructures that support male or female reproductive structures.Seeds are produced in female cones. Male cones produce cloudsof pollen.What are gnetophytes?Gnetophytes (NEE toh fites) are divided into three groups.One group contains tropical trees and climbing vines.
The secondgroup includes shrubs that grow in dry, desert regions. The thirdis a single species that lives in the deserts of southwest Africa.240Chapter 21READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.3. What do all seed plantshave in common?NameDateClassSection21.2Survey of the Plant Kingdom, continuedWhat are ginkgophytes?There is only one living species in this division, the Ginkgobiloba. Ginkgoes (GING kohs) are small trees with fan-shapedleaves. Like cycads, ginkgoes have male and female reproductivestructures on separate trees.
Because the seeds produced onthe female tree have an unpleasant smell, male ginkgoes are usually planted.What are conifers?4. How many differentspecies are in the ginkgophyta division?________________________________________________________________________Conifers (KAH nuh furz) are cone-bearing trees such as pine,fir, cypress, and redwood. Conifers produce seeds in cones. Manyconifers have needlelike leaves.
Bristlecone pines, the oldest livingtrees in the world, are conifers. The Pacific yew, another type ofconifer, is a source of cancer-fighting drugs.What are anthophytes?Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Anthophytes (AN thoh fites) are the flowering plants. Thereare approximately 250 000 species of anthophytes. Anthophytesproduce flowers from which fruits develop.
A fruit usually contains one or more seeds. Anthophyta is broken into two classes.You will learn about those in a later chapter.◗ After You ReadMini Glossarycones: scaly structures produced by some seedplants that support male or female reproductive structures and are the sites ofseed productionfrond: fern leaves; may vary in length from 1 cmto 500 cm1.
Review the terms and their definitions in the Mini Glossary above. Then on the blank linesbelow, use each term in a sentence.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________READING ESSENTIALSChapter 21241NameDateClassSection21.2Survey of the Plant Kingdom, continued2.
Read each sentence below the diagram. If the statement describes non-seed plants, writeits letter in the Non-seed box. If the statement describes seed plants, write its letter in theSeed box.PlantsPlants are divided into two groupsbased on whether or not a plantproduces seeds.Non-seedSeeda. There are seven divisions of these plants.b. These plants release seeds.c. These plants release reproductive cells called spores.d. There are five divisions of these plants.e.
These plants may be either vascular or nonvascular.f. These plants contain a plant organ made up of an embryonic plant and a food supplycovered by a hard protective coat.Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.g. All of these plants are vascular.Visit the Glencoe Science Web site at science.glencoe.com to findyour biology book and learn more about surveying the plant kingdom.242Chapter 21READING ESSENTIALSNameDateClassSection22.1 Nonvascular Plants◗ Before You ReadSC.F.1.4.2 The student knows that body structures are uniquely designed and adapted fortheir function. SC.F.2.4.1 The student understands the mechanisms of asexual and sexualreproduction and knows the different genetic advantages and disadvantages of asexualand sexual reproduction.You will learn more about mosses in this section.
Mosses are among the first plants to grow in anarea after a fire or where the ground has been disturbed in some way. For this reason, moss is oftencalled a pioneer species. How might a habitat benefit by pioneer species such as moss? Write yourthoughts on the lines below.______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________◗ Read to LearnCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.What is a nonvascular plant?If you live in a moist environment, you are likely to see nonvascular plants.
That is because nonvascular plants need to be nearwater for life functions such as reproduction and photosynthesis.A steady supply of water is not available everywhere, thereforenonvascular plants are limited to moist habitats near streams andrivers, or in temperate and tropical rain forests. Nonvascularplants do not have roots.How is alternation of generations unique innonvascular plants?Remember that the life cycle of all plants includes an alternation of generations between a diploid sporophyte and a haploidgametophyte.
In nonvascular plants, the gametophyte generationis dominant. Sporophytes depend on gametophytes for water andother substances. Sporophytes grow attached to the gametophytes.The illustration at right shows sporophytes growing attached tothe gametophytes.Gametophytes of nonvascular plants produce two kinds of sexual reproductive structures. The male reproductive structure iscalled the antheridium (an thuh RIH dee um).
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