Reading Essentials for Biology Glencoe, страница 10

In fact, many desert plants needlittle rainfall. Their leaves, stems, and coatings conserve water.Many also have spines, thorns, or poisons to protect againstplant eaters.Many small desert mammals are plant eaters that hide duringthe heat of the day and search for food at night. The kangaroo ratis a plant eater that does not have to drink water. Instead, theserodents get water from the plants they eat. Coyotes, hawks, andowls are meat eaters. They feed on snakes, lizards, and smalldesert mammals. Scorpions and some snakes use their venom tocapture their prey.Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.What is the grassland biome?Grasslands, or prairies, are large communities covered withrich soil, grasses, and other grasslike plants.

Grasslands mostoften exist in climates that have a dry season. In this type of biome,there is not enough water to support forests. Many of the grassesdie off each winter, but the roots of the grasses survive andenlarge every year. This forms a continuous underground matcalled sod.Grasslands are known as the breadbaskets of the world becauseof the many types of grains that can grow there.

Many otherplants grow well there too, including wildflowers. At some timesof the year, the grasslands are populated by herds of grazinganimals including deer and elk. Other prairie animals includejackrabbits and prairie dogs. Foxes and ferrets prey on prairiedogs.

Many species of insects, birds, and reptiles also make thegrasslands their home.4. Infer Because of themany types of grains thatcan grow in these areas,they are called the breadbaskets of the world.(Circle your choice.)a. tundrasb. grasslandsc. tropical rain forestsWhat is the rain forest biome?Rain forests are home to more types of life than any otherbiome. There are two types of rain forests—the temperate rainforest and the tropical rain forest.

Tropical rain forests havewarm temperatures, wet weather, and lush plant growth. They arelocated near the equator. The hot climate of these rain forestsallows organisms to decay quickly. Plants must quickly absorbthese nutrients before they are carried away from the soil by rain.Temperate rain forests are less common, but they also have largeamounts of moisture.READING ESSENTIALS5.

What are the two typesof rain forests?________________________________________________Chapter 331NameDateClassSection3.2Biomes, continuedWhat is the temperate forest biome?Temperate or deciduous forests have precipitation thatranges from 70 to 150 cm annually. The soil has a rich humus toplayer and a deeper layer of clay. If mineral nutrients in the humusare not immediately absorbed by roots, they might be washed intothe clay and lost from the food web for many years. The forestsare thick with broad-leaved trees that lose their leaves every year.Some of these trees are maple, oak, and elm.

Animals that live inthis biome include mice, rabbits, bears, and many different birds.◗ After You ReadMini Glossarydesert: an arid region with sparse to almost noplant life; the driest biomeestuary (ES chu wer ee): coastal body of water,partially surrounded by land, where saltwater and freshwater mixgrassland: biome of large communities coveredwith rich soil, grasses, and similar plantsintertidal zone: the area of shoreline that liesbetween the high and low tide linesphotic zone: portion of the marine biome that isshallow enough for sunlight to penetrateplankton: small organisms that drift and float inthe waters of the photic zonetaiga (TI guh): the biome just south of the tundra;characterized by a boreal or northern coniferous forest composed of fir, hemlock, andspruce trees and acidic, mineral-poor soilstemperate/deciduous forest: biome composedof forests of broad-leaved hardwood treesthat lose their foliage annually; receives70–150 cm of precipitation annuallytropical rain forest: biome located near theequator; has warm temperatures, lots ofrain, and lush plant growthtundra: the biome that circles the north pole;treeless land with long summer days andshort periods of winter sunlight1.

Review the terms and their definitions in the Mini Glossary above. Use one of these termsthat describes a biome in a complete sentence. Write your sentence in the space below.________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________32Chapter 3READING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.biome: a group of ecosystems with the same climax communities; biomes on land are calledterrestrial biomes, those in water are calledaquatic biomesNameDateClassSection3.2Biomes, continued2. Fill in the blanks below with the following words to make correct statements about thematerial you read in this section: desert, tundra, plankton, photic zone, rain forest.a.

Thebiome is home to more types of life than any other biome.b. Theis so cold that very little life exists there.c. The driest biome is thebiome.d. The part of the marine biome that is shallow enough for sunlight to penetrate is called the.e. The base of the entire marine biome food chain is formed by.Copyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Visit the Glencoe Science Web site at science.glencoe.com to findyour biology book and learn more about biomes.READING ESSENTIALSChapter 333NameDateClassSection4.1 Population DynamicsSC.G.1.4.1 The student knows of the great diversity and interdependence of living things.

Also covers SC.D.2.4.1,SC.G.2.4.5◗ Before You ReadThis section discusses populations—how they grow and why they stop growing. The factors thataffect how populations grow and why they stop growing are called population dynamics. What populations of living things can you observe where you live? Think about populations of plants and animals near your home.

List them below. Have those populations ever increased or decreased? Writedown reasons for changes in those populations.__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________◗ Read to LearnIdentifyGrowth Factors Highlightthe factors that affect thegrowth of populations.Every organism is a member of a population. A population is agroup of organisms of the same species that live in a specific area.You may have a population of grass in your backyard. There alsomay be a population of ants there.

You may even have a population of bacteria on your bathroom door handle.Populations grow, die, increase, and decrease. Factors thataffect the growth rate of populations include food, space, disease,and predators. Scientists have discovered that populations oforganisms tend to grow in the same way. Populations start bygrowing slowly. In the beginning, there are just a few organismsthat reproduce. Soon the rate of population growth increasesbecause there are more organisms reproducing.Population Growth of HousefliesPopulation size1 million500 00010034Chapter 4One yearHow do populations grow?Scientists use graphs to show how populations grow.

The graph of a growing populationlooks like a J-shaped curve. The flat part of theJ shows slow growth. The part of the J thatrises shows rapid growth. The J-shaped curve isa picture of exponential growth. Exponentialgrowth means that as a population gets larger,it grows at a faster rate. For example, you mayhave one dandelion in your backyard.

A fewweeks later you may have twenty dandelions.A few weeks after that you may have hundredsof dandelions. The reason is exponentialREADING ESSENTIALSCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.Principles of Population GrowthNameDateClassSectionPopulation Dynamics, continuedFoodPredatorsExponentialgrowthSpaceCharacteristics of Population GrowthDiseasegrowth. One dandelion produces manyseeds. Twenty dandelions produce hundreds of seeds.Can populations grow and never stopgrowing? No, there are factors that slowdown or limit growth. These are calledlimiting factors. The effects of limitingfactors also can be shown on a graph.The J-shaped curve begins to look likean S-shaped curve as population growthslows or levels off.When populations run out of food orspace, growth starts to slow down. Population growth also slows when disease orpredators attack populations.

Later, youwill read about other reasons why population growth slows.CarryingcapacityPopulation4.1J curveS curve0TimeCopyright © by Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.What is an environment’s carrying capacity?The carrying capacity of an environment is the number oforganisms of one species that can be supported for an unlimitedamount of time. Until carrying capacity is reached, there aremore births than deaths in the population.