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1UNIT
UNiT TASK PrEvIEw
In this Unit Task you will select a group of organisms and then examine the roles they play in supporting ecosystems You will investigate specifi c threats to their diversity by examining how human actions are infl uencing the group in both negative and positive ways
The Unit Task is described in detail on page XXX As you work through the unit look for Unit Task Bookmarks to see how information in the section related to the Unit Task
diversity of Living Things
oVerALL eXpectAtionsbull analyzetheeffectsofvarious
humanactivitiesonthediversityoflivingthings
bull investigatethroughlaboratoryandorfieldactivitiesorthroughsimulationstheprinciplesofscientificclassificationusingappropriatesamplingandclassificationtechniques
bull demonstrateanunderstandingofthediversityoflivingorganismsintermsoftheprinciplesoftaxonomyandphylogeny
BiG iDeAsbull Alllivingthingscanbeclassified
accordingtotheiranatomicalandphysiologicalcharacteristics
bull Humanactivitiesaffectthediversityoflivingthingsinecosystems
NEL2 Unit 1 bull Diversity of Living Things
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Focus on STSE
A First or LAst chAnce to seeThe biosphere contains an astounding diversity of living things Living things inhabit virtu-ally every square metre of Earthrsquos surface from the deepest ocean trenches to the highest mountain tops Life comes in a truly astonishing array of shapes and sizes both familiar and bizarre You may recognize and admire bald eagles humpback whales and polar bears but know little about or even fear vampire bats tarantulas and giant squid
Biologists discover new types of living things daily but they have catalogued only a fraction of the millions of different kinds of living things thought to inhabit the Earth Biologists also continue to discover important interconnections among organisms For example most plants rely on soil fungi to get nutrients from the soil and most animals depend on microbes living within their bodies to help them digest food
You are fortunate because you will have the opportunity in your life to admire study and benefit from the millions of kinds of organisms with which you share this planet If you are lucky you may see moose while hiking or paddling through Ontariorsquos beautiful old growth forests or examine the several species of small carnivorous plants that live in Ontario bogs You may travel to an ocean to go whale watching or scuba over a coral reef or perhaps visit a tropical rainforest
Unfortunately opportunities like this are limited by past human actions and may be limited even more in the future Climate change habitat destruction pollution and the introduction of invasive organisms are posing a serious threat to the diversity of life on a global scale For the many living things that are endangered the situation is grave The years ahead may be our last chance to see them before they go extinct
The situation however is far from hopeless Actions and decisions we make today can help sustain healthy ecosystems and conserve the diversity of life on Earth Wise choices today can ensure that future generations have a chance to see admire and experience this amazing diversity of life
Questions 1 Some kinds of organisms are far more dramatic than others People often marvel
at their first sight of an elephant or whale a beautiful flower or a towering tree (a) In a small group brainstorm a list of 10 or more of the most interesting kinds
of organisms Provide reasons for your selections(b) Which of these organisms have you seen in real life Which would you like to
see K TI A
2 Humans are very dependent on other organisms for survival Other organisms supply us with foods clothing medicines and building materials (a) Did your list of organisms in question 1 include organisms that benefit you (b) In your group make a second list of 10 or more organisms that you think are
most important to humans Explain your reasoning TI A
3 Although people are most familiar with plants and animals the living world also contains many kinds of fungi protists and other microorganisms Do you think these organisms are as important as plants and animals Why or why not TI A
4 Many scientists are very concerned about threats to Earthrsquos diversity of life Do you share this concern What responsibility do you think we have to protect the diversity of life TI A
Focus on STSE 3NEL
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unit 1 ArE you rEAdy
Concepts review 1 The following key terms are associated with the ways
in which scientists gather information and conduct investigations Explain the meaning of each term Ku TI
(a) hypothesis(b) independent variable(c) dependent variable(d) controlled experiment
2 Decide if the following statements are true or false If they are true copy them directly into your notebook If they are false rewrite each statement to make it true Ku
(a) All living things are made up of many cells(b) Living things grow reproduce and repair
themselves(c) Most living things require energy to function(d) Animals respond to changes in their environment
but plants do not(e) All organisms perform photosynthesis but only
plants perform cellular respiration 3 Match the terms with the statements below Ku
(a) mutualism(b) symbiosis (c) parasitism (d) commensalism (i) a situation in which two organisms live in
close contact and at least one benefits (ii) a situation in which one organism lives in or on
another organism and feeds on that organism (iii) a situation in which two organisms live in
close contact and both benefit (iv) a situation in which two organisms live in
close contact One benefits and the other is not affected
4 Describe the relationships among an embryo tissues and the process of cell differentiation Ku
5 Many biology news stories refer to advances in genetics How are the terms ldquogeneticrdquo and ldquogenetic informationrdquo related to chromosomes DNA and inherited information Ku TI
6 State the function of each of the following Ku
(a) chromosomes(b) mitochondria(c) chloroplasts(d) flagella(e) DNA(f) ribosome(g) nucleus
7 Compare and contrast the following terms Ku
(a) cell wall and cell membrane(b) unicellular and multicellular(c) mitosis and the cell cycle
8 State the function of each of the following Ku
(a) muscle tissue(b) nervous tissue(c) vascular tissue(d) epithelium
9 We are most familiar with plants and animals but they are just two groups of organisms on Earth List 2 or 3 characteristic features of the following groups of living things Ku
(a) protists(b) fungi(c) bacteria
10 Brainstorm a list of different kinds of organisms that might live in a particular habitat such as a forest field or pond Then draw a hypothetical food web that shows how they are interconnected TI C
conceptsbull understandscientificterminologyrelatedtocells
organismsandecosystems
bull compareandcontrastdifferentkindsofcells
bull recognizethepostulatesofthecelltheory
bull understandthatalllivingthingsareinterdependent
bull recognizethathumanactionsinfluencespeciesandthesustainabilityofecosystems
skiLLs bull makebiologicaldrawings
bull properlyuseandcareforamicroscope
bull preparedryandwetmountslides
bull makeandrecordcarefulobservations
bull communicateideasplansproceduresresultsandconclusionsusingappropriatescientificterminologyandformats
bull analyzeandinterpretqualitativeandquantitativedata
4 Unit 1 bull Diversity of Living Things NEL
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11 How does a food web illustrate the interdependence of one kind of organism on another Use an example from your food web to explain what would happen to the ecosystem if one kind of living thing were removed TI A
12 Give one or two examples of ways in which living things influence and are dependent upon(a) the carbon cycle(b) the water cycle(c) the nitrogen cycle Ku A
13 Humans interact with other kinds of living things in many ways Some of these interactions are harmful to ecosystems Match the term on the left with the description of interaction on the below Ku A
(a) invasive species(b) monoculture(c) climate change(d) extirpation (i) Humans are producing large quantities of
greenhouse gases that trap thermal energy (ii) Habitat loss and pollution can lead to the loss
of a species from a particular region (iii) Humans often introduce organisms into new
environments with unforeseen consequences (iv) Humans often grow crops in large fields
containing a single kind of plant 14 Humans can also act to ensure that ecosystem remain
sustainable Ku TI A
(a) What does ldquosustainablerdquo mean(b) Give an example of an action you could take to
improve the sustainability of ecosystems(c) How is the sustainability of an ecosystem influenced
by the diversity of living things in the ecosystem 15 You like all humans depend on other organisms for
food But food is only one of the many benefits to humans of other organisms Brainstorm and list of the many ways that you benefit of other organisms in your daily life TI C A
Skills review 16 Examine the cells in Figure 1 Ku TI A
(a) Identify each cell as a plant animal bacteria or protist Give reasons for your choices
(b) What evidence suggests that some of these organisms have the ability to move
(c) What evidence suggests that one of these organisms has the ability to produce its own food
17 List the characteristics of a good biological drawing Ku
18 Make a biological drawing of one of the cells in Figure 1 Ku C
19 Describe how you would make a wet mount of a sample of banana cells C
20 Describe the step-by-step procedure you would use to observe cells under high power TI C
21 Suggest several safety precautions that you think should be taken when studying live organisms A
CAREER PATHWAYS PrEvIEw
Throughout this unit you will see Career Links in the margins These links mention careers that are relevant to the Diversity of Living Things On the Chapter Summary page at the end of each chapter you will find a Career Pathways feature that shows you the educational requirements of the careers There are also some career-related questions for you to research
NEL Are You Ready 5
Figure 1
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TheenspfollowingenspiconsenspindicateensptheenspAchievementenspChartenspcategoryenspaddressedenspbyenspeachenspquestion
KU ensp KnowledgeUnderstanding TI ensp ThinkingInvestigationC ensp Communication A ensp Application
UNIT
B SELF-QUIZ
for each question select the best answer from the four alternatives
1 What are producers able to do that consumers cannot (24) KU
(a) cycle energy in ecosystems(b) make their own food(c) release energy from food (d) generate thermal energy
2 Th e unique way a species interacts with other species and with its environment is called (25) KU
(a) a trophic level(b) a feeding role(c) an ecological niche(d) a food chain
3 Which of the following is an example of a biotic factor (22 27) KU
(a) sunlight(b) grass(c) soil(d) water
4 Which of the following is true about pesticides (44 45) KU
(a) Pesticides are toxic only to the target species
(b) Pesticides tend to reduce overall food production
(c) Pesticides are used to replace nutrients in soil
(d) Pesticides can pass from an organism to its consumer
Indicate whether each of the statements is true or false If you think the statement is false rewrite it to make it true
5 Primary succession occurs in an ecosystem that has been partially disturbed by an event such as a forest fi re (32) KU
6 Fragmentation of an ecosystem occurs when the ecosystem is divided into smaller parcels making it more sustainable (34) KU
7 A threatened species is a species that may become endangered if current trends continue (33) KU
Copy each of the following statements into your notebook fill in the blanks with a word or phrase that correctly completes the sentence
8 Groundwater can become contaminated with nitrogen compounds from fertilizers through a process called (42) KU
9 An environment and all its organisms form a(n) (22) KU
Match each term on the left with the most appropriate description on the right
10 (a) producer (i) the feeding position of an organism along a food chain
(b) consumer (ii) an organism that obtains energy by eating other organisms
(c) decomposer (iii) a network of feeding relationships within a community
(d) food chain (iv) an organism that obtains energy by eating dead organic matter
(e) food web (v) an organism that obtains energy by making its own food
(f) trophic level (vi) a sequence of organisms each feeding on the next (24 25) KU
Write a short answer to each of these questions
11 List three examples of products we obtain from terrestrial ecosystems (31) KU
12 Explain the diff erence between a population and a community (22) KU
13 Predation and parasitism are two examples of species interactions (27) KU
(a) How are predation and parasitism alike (b) How are they diff erent
164 Unit B bull Sustainable Ecosystems NEL
6646_Sci9_ch04_pp148-165indd 164 71709 60804 PM
ch
Ap
ter
1keY conceptsIn this chapter you will be able to
bullensp describe the nature of biological diversity and the biological species concept
bullensp outline some of the primary human-caused threats to Earthrsquos biodiversity
bullensp explain the principles of taxonomy and phylogeny and the concepts of taxonomic rank
bullensp describe and compare traditional and modern biological classifi cation systems
bullensp outline some of the key features used to classify all living organisms into six kingdoms
bullensp construct and apply dichotomous keys for the purpose of identifying species
bullensp use appropriate sampling methods to collect specimens from an ecosystem and classify them using scientifi c criteria
what Connects Life on EarthLife can be found almost everywhere Organisms live at the bottom of the ocean abyss deep underground on icy mountaintops and in boiling hot springs Even our own bodies are home to countless millions of microscopic organismsmdashwe are their habitat
Emperor penguins show many of the most dramatic and fascinating quali-ties of living things such as the ability to live and fl ourish in extreme environ-ments Emperor penguins begin life by hatching from an egg during sunless days on a sheet of ice in the most inhospitable continent on EarthmdashAntarctica Surviving temperatures of ndash60 degC they are cared for and protected by their parents until they are able to march for tens of kilometres to the waterrsquos edge As they plunge into the icy water they transform from awkward waddlers into majestic high performance swimming machines faster and more agile than almost any fi sh
As unique and marvellous as penguins are they are just one of the millions of remarkable organisms on Earth Our planet is also home to elephants with noses that drag on the ground albatrosses that can stay airborne for more than a year at a time and deadly poisonous stonefi sh hiding in coral reefs Some eastern white cedar trees living in Ontario are over 1000 years old
Th e diversity of life is truly extraordinary It is also immeasurably valuable All organisms including humans depend on other organisms for survival Other organisms provide us with oxygen clean air and water food medicines and building materials But throughout the world native plant and animal populations are declining due to habitat loss pollution over-harvesting and competition with invasive species Many species are threatened with extinction
In this chapter you will examine the grandeur of life beginning with an ex-ploration of the diversity of life and our dependence on it You will learn how organisms are identifi ed and classifi ed and gain insights into why scientists are so concerned about the threats to the diversity of life
understanding Biodiversity
Answer the following questions using your current knowledge You will have a chance to revisit these questions later applying concepts and skills from the chapter
1 How many different kinds of living things do you think there are on Earth How might this diversity be important or valuable
2 How do you think organisms can be distinguished from one another
3 What do you think are the benefi ts of naming and classifying (or grouping) living things How might this be accomplished
STARTiNg PoInTS
6 Chapter 1 bull Understanding Biodiversity NEL
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Identify Exceptional organisms
Skills Questioning Predicting Communicating
A good way to begin a study of the diversity of life on Earth is to consider the great variety of organisms that you are already familiar with In this activity you will brainstorm examples of living things that fall into given categories and suggest some categories of your own
1 Working in small groups brainstorm examples of organisms on Earth that you think best fi t the following categories
You may list more than one kind of organism for each category but you must identify which of these you think is the ldquobestrdquo choice
2 Record your choices in a table or other suitable format
3 Have a class discussion in which groups argue in favour of their selections Be prepared to change your mind if others have a better case for their choice
A Which categories are based on opinion and which are based on an objective characteristic TI
B Did everyone interpret the categories in the same way Did ldquovaluablerdquo or ldquodangerousrdquo have the same meaning for everyone TI
C Were there any choices that almost everyone agreed with Why do you think that was the case TI
Mini Investigation
SKILLSHANDBOOK tk
bullensp largestensplivingenspanimal
bullensp mostenspbeautifulensporganism
bullensp smallestenspplant
bullensp mostenspvaluableenspfood
bullensp mostenspunusualenspanimal
bullensp mostensppowerfulensppredator
bullensp mostenspdangerousensporganism
bullensp mostenspcolourfulenspanimal
bullensp mostenspvaluableenspfungus
bullensp fastestensprunner
bullensp fastestenspflenspyer
bullensp fastestenspswimmer
bullensp threeenspmoreenspcategoriesenspof your own choosing
Introduction 7NEL
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11
Figure 1 Biologists continue to discover new species such as the deep ocean Dumbo octopus
BiodiversitymdashAn introductionLife on Earth is extraordinarily diverse The variety of species on Earth or in any eco-system on Earth is called biological diversity or biodiversity By 2010 the International Year of Biodiversity over 17 million kinds of living things had been identified and described by scientists This number continues to grow as new organisms are dis-covered daily Among them are strange creatures from the depths of Earthrsquos oceans (Figure 1) brightly coloured rainforest birds and some peculiar organisms such as tree kangaroos Biologists believe that Earth may be home to as many as 15 million different kinds of living things
In order to assess the diversity of life scientists must observe and accurately de-scribe each kind of living thing With millions of different kinds of organisms where do scientists begin The first step is to choose a fundamental unit In the case of living things this unit is the species However defining and identifying this unit is not always easy
what Is a SpeciesMost biologists define a species as a group whose members are able to freely breed among themselves under natural conditions This definition is also referred to as the biological species concept It is important to note that members of different species usually do not breed with one another For example under natural conditions lions breed only with lions robins breed only with robins and lobsters breed only with lobsters
In many cases the difference between species is quite obvious For example you would never mistake an elephant for a hippopotamus or an ostrich for a turkey Unfortunately the definition of species above does not fit all living things as well as it does elephants and ostriches Plants for example offer many exceptions Two plants that appear to be distinct species may occasionally undergo hybridization under natural conditions forming a cross between the two species Although hybridization in nature does occur it is relatively uncommon Other plants some fungi and many microscopic organisms (microorganisms) only reproduce asexually For these organisms the spe-cies definition does not apply When this is the case species are defined based on a set of physical characteristics or morphology For example dandelions (which reproduce asexually) are defined by their shared features rather than as members of a population of breeding individuals
Individual variabilityAtoms of an element or molecules of a compound are identical but a species is composed of individuals with different characteristics Just as no two humans look exactly the same the individuals of any given species may show subtle differences (Figure 2) However these individuals still belong to the same species and are mem-bers of the same breeding population
As you will learn in the Genetic Processes unit biologically inherited information (called genetic information) is a primary source of individual vari-ability While the study of the diversity of living things focuses on distinctions among species individual variability is vital to both individuals and entire populations
species all organisms capable of breeding freely with each other under natural conditions
hybridization the crossbreeding of two different species
morphology the physical appearance and characteristics of an organism also the science of the study of these physical characteristics
biodiversity the variety of species and ecosystems on Earth organisms on Earth or in an ecosystem
Figure 2 Humans exhibit individual variability but are all members of the same species
8 Chapter 1 bull Understanding Biodiversity NEL
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