Diversity of Living Things Unit 1 Chapter 1: Understanding Biodiversity The variety of life forms on Earth is called biodiversity, comprising species diversity, genetic diversity, structural diversity, and individual variability. All species are dependent in a variety of ways on this diversity. All organisms are classified into different groups based on physical and evolutionary characteristics, making it easier for scientists to study and define, and to share knowledge with one another. Biodiversity also encompasses the diversity in ecosystems: diversity of habitats and interactions. Loss of biodiversity threatens the health of ecosystems and thus the survival of all species. Chapter 2: The Prokaryotes, Viruses, and Protists Prokaryotes, viruses, and protists are the most abundant organisms on Earth and they are not visible to the unaided human eye. Prokaryotes include all the organisms in the Kingdoms and Domains Eubacteria (Bacteria) and Archaea. Bacteria play key roles as decomposers and pathogens, and in the production of foods and medications. Archaea live in extreme conditions, but little else is known about them. Viruses are responsible for many human diseases ranging from the common cold and chicken pox to AIDS, cholera, and rabies. Many viruses are harmful, but they are important in ecosystems as a means of population control. They may also be used in gene therapy to deliver drugs or genes to cells. The smallest eukaryotes and some of the largest belong to the Kingdom Protista, including all eukaryotes other than fungi, plants, or animals. Protists play key roles in aquatic ecosystems. As a result of this extreme diversity, there is no typical protist. Protists exhibit a wide variety of cell features, different ways of moving (if they move at all), different ways of getting nutrients and energy, and very different methods of reproducing. Big ideas All living things can be classified according to their anatomical and physiological characteristics. Human activities affect the diversity of living things in ecosystems. Chapter 3: The Fungi, Plants, and Animals Fungi, plants, and animals are organisms that have adapted to living in the variable and challenging conditions of terrestrial ecosystems. Adaptations include mechanisms for dealing with changes in temperature, loss of water, and the need to support their own mass. They have also adapted to life on land with each other and have established many relationships: producer and consumer, predator and prey, and symbiotic relationships. NEL Unit 1 Overview 1
1.1 Biodiversity An Introduction Textbook pp. 8 13 Main idea: The biological species concept defines species as a population of individuals that are able to freely breed under natural conditions. Biologists have identified and described more than 1.7 million species. 1. Would you expect that bald eagles and red-tailed hawks would be able to breed with each other? Explain. T / I 2. Which two types of organisms are exceptions to the biological species concept? Explain why. T / I Main idea: All species depend on other species in a variety of ways for their own survival. 3. Create a flowchart in the space below that shows the direction in which energy from food flows through the following organisms: heterotrophs, micro-organisms, autotrophs. Label each step in the process. K/U C 4. Fill in Table 1 with an example of each type of species interaction. K/U Table 1 Interactions Between Species Interaction Example Food supply Protection Transportation Reproduction Hygiene Digestion 2 Unit 1 Diversity of Living Things NEL
Main idea: Biodiversity refers to the variety of species in an ecosystem but also includes structural diversity within ecosystems and individual variability within species. 5. Complete Table 2 to compare different types of biodiversity. T / I Table 2 Three Types of Biodiversity Type of Biodiversity genetic diversity species diversity structural diversity Description and Example Study Tip A diverting activity? The word diverge means to go in different directions. The word diversity, which means variety, comes from the same Latin words and has a related meaning in the terms biodiversity, species diversity, genetic diversity, and structural diversity. Look for other words that use the Latin roots prefix dis- and the root verge- and learn their definitions. 6. A plantation of white pine trees that are all the same age is sure to be lacking which two types of biodiversity? Explain why. T / I Main idea: Species evolve over time and space. 7. In your own words, explain what is meant by the statement Species evolve over time and space. K/U T / I 8. The physical and behavioural changes that occur in an entire population of a species over time are called. K/U Main idea: Although new species are still being discovered, biodiversity is under threat from many human activities. 9. In your own words, explain how today s high rate of species extinctions is different from previous mass extinctions. K/U 10. List four ways that the loss of biodiversity affects humans and other species. K/U (i) (ii) (iii) (iv) NEL 1.1 Biodiversity An Introduction 3
1.2 The Nature of Classification Textbook pp. 14 20 Vocabulary biological classification botanist binomial nomenclature kingdom taxonomy genus taxon dichotomous key Main idea: Classification systems are useful, but extremely variable. 1. In your own words, write a definition for biological classification. K/U 2. Give an example of an organism that fills each of the following ecosystem roles. K/U (a) producer: (b) herbivore: (c) carnivore: (d) scavenger: Main idea: The science of classifying living things is called taxonomy. 3. What is another term for taxonomy?. K/U 4. In Table 1 below, list three types of observed characteristics that help biologists identify organisms and an example of each characteristic. K/U Table 1 Observed Characteristics Types of observed characteristics Examples 5. Fill in the Venn diagram below to show the similarities and differences between Siamese cats and poodles. K/U A Siamese cats Poodles 4 Unit 1 Diversity of Living Things NEL
6. List three challenges that make identifying species challenging. T / I Main idea: Traditional taxonomy groups species together according to shared characteristics. 7. Carl Linnaeus is considered the father of taxonomy. What did he introduce to the science of classification? K/U 8. Carl Linnaeus considered species to be types of living things that could be grouped into according to shared characteristics. K/U Main idea: All species are given a unique binomial (two-word) species name. 9. What is the formal system now used to name species? K/U 10. In the name Ursus maritimus, is the genus name, and is the species name. T / I 11. Of Ursus maritimus, Ursus americanus, and Numenius americanus, which two species are most closely related? Explain how you can tell. T / I Main idea: Traditional taxonomy groups species into a number of major levels, or taxa. Scientists often disagree about the criteria used to group species. 12. In the Linnaean system, each taxon consists of species that have similar features. Provide two characteristics that only organisms in class Mammalia possess. K/U T / I 13. Based on traditional taxonomy and information in the text, fill in the blanks in Table 2 below. K/U T / I Table 2 Human and Honey Bee Taxa Names Taxon Human Honey Bee Animalia Animalia Learning Tip Naming Species The first word of a binomial species name is always capitalized. The second word is always lowercase. Both words are printed in italics. The names of other taxonomic levels are normally capitalized. Binomial species names can also be abbreviated. For example, Homo sapiens can be written H. sapiens. Study Tip Taxa Mnemonic Devices A common mnemonic device for remembering the order of the traditional taxa from least to most specific is King Philip came over from Germany stunned (Kingdom Phylum Class Order Family Genus Species). Try to come up with your own. phylum Mammalia Primates Hominidae Insecta Hymenoptera Apidae genus species (binomial) Homo sapiens Apis mellifera 14. What issue do scientists often disagree about when they are trying to classify species? K/U NEL 1.2 The Nature of Classification 5
MAin idea: Dichotomous keys are often used to help identify species. 15. Briefly explain how to use a dichotomous key to identify an organism. K/U 16. Complete the following dichotomous keys using the bird illustrations below. T / i C A bill elongated bill strongly curved... bill straight bill uniform in width... (a) (b) bill greatly widened at end... (c) bill not elongated bill straight... (d) bill strongly hooked... (e) spoonbill heron ibis eagle cardinal 6 Unit 1 Diversity of Living Things NEL
Phylogeny and Modern Taxonomy 1.3 Vocabulary evolution phylogeny phylogenetic tree clade Textbook pp. 21 25 MAin idea: Modern biological classification is based on phylogeny, which is the evolutionary relatedness of species. 1. In your own words, describe the theory of evolution. K/U C STUDy TiP The Phyl- Family The root word of both phylum and phylogeny comes from the Greek root phyl-, or tribe. Look for other scientifi c words that use this root word. 2. How is phylogeny different from the relationships shown in a family tree? T / i MAin idea: Phylogenetic trees are used to show evolutionary relationships among species and groups. 3. What do the individuals in a family tree have in common with the groups of organisms in a phylogenetic tree? T / i 4. What types of evidence support the relationships shown in phylogenetic trees? K/U 5. In Figure 1, label the top and bottom of the arrow at the right of the phylogenetic tree to represent the passage of time. K / i rhinoceros horse zebra Figure 1 NEL 1.3 Phylogeny and Modern Taxonomy 7
MAin idea: A clade is a taxonomic group that includes all the descendants of a common ancestor. Use Figure 2 below to answer questions 6 to 8. Figure 2 6. How many clades are shown in Figure 2 above? Which of the animals belong to each of the clade(s)? T / i 7. What part of Figure 2 above represents the common ancestor of all of the animals? T / i 8. In Figure 2, do the gull and the fox form a clade? Explain why or why not. T / i MAin idea: Both traditional and phylogenetic classifi cation systems have advantages and disadvantages. 9. Fill in Table 1 below with the advantages and disadvantages of traditional and phylogenetic classification. T / i Table 1 Classifi cation Advantages and Disadvantages Advantages Disadvantages Traditional classifi cation Phylogenetic analysis 8 Unit 1 Diversity of Living Things NEL
Kingdoms and Domains Vocabulary prokaryote eukaryote domain 1.4 Textbook pp. 26 29 Main idea: Most biologists classify living things using a system of six kingdoms and three domains. 1. Match the organisms on the left with their correct definition on the right. K/U (a) prokaryotes (i) unicellular and small multicellular organisms with organelles (b) eukaryotes (ii) organisms that have organelles but that are not fungi, plants, or animals (c) protists (iii) unicellular organisms without membrane-bound organelles 2. Are pine trees prokaryotes or eukaryotes? Explain. T / I 3. Complete the tree diagram below to show how the three domains relate to the six kingdoms of life. T / I All organisms Learning Tip Name Change Archaea used to be called Archaebacteria, but we now know that they are distinct from Eubacteria, the true bacteria. Domain Eubacteria Domain Domain Kingdom Kingdom Archaea Kingdom Kingdom Kingdom Plants Kingdom 4. Your classmate states that some animals are prokaryotes. Do you agree or disagree? Explain. T / I C Main idea: The most easily recognized kingdoms of life are Animals, Plants, and Fungi. Eubacteria and Archaea are the most difficult to distinguish. 5. What is one reason why we most easily recognize organisms that belong to the fungi, plant, and animal kingdoms? T / I 6. Are Eubacteria and Archaea prokaryotes or eukaryotes? Explain. K/U 7. Eubacteria are commonly called. K/U Study Tip Rhyming Helps You can distinguish Archaea and Eubacteria easily for yourself by remember the rhyming phrase Eubacteria are true bacteria. In fact, many scientists do not consider Archaea bacteria, so they simply call the domain Eubacteria Bacteria. Come up with other rhyming phrases that can help you remember scientific facts. NEL 1.4 Kingdoms and Domains 9
8. Most prokaryotes consist of cells, but some others consist of K/U Main idea: Protista is the only kingdom that does not represent a clade. 9. Give two examples of protist characteristics that demonstrate their diversity. K/U 10. Give two reasons why protists are not considered a clade. K/U Main idea: The six-kingdom, three-domain system is based on phylogenetic relationships revealed by genetic evidence. Use Figure 1 below to answer Questions 11 to 13. Eubacteria Archaea Eukaryotes purple bacteria cyanobacteria flavobacteria gram positives thermotogales green nonsulfur bacteria thermoproteus pyrodictium methanobacterium methanococcus methanosarcina haloarchaea entamoebae slime moulds microsporidia animals fungi ciliates plants flagellates trichomonads diplomonads Figure 1 Domain diagram Most recent common ancestor of all living organisms 11. Judging from the evolutionary relationships shown in the diagram of the domains of life (Figure 1), are eukaryotes more closely related to Archaea or Eubacteria? Explain. C A 12. Why are animals, plants, and fungi so close together on the rightmost tree in the domain diagram above (Figure 1)? T / I 13. Do you think the domain diagram could change? Explain. T / I 10 Unit 1 Diversity of Living Things NEL
1.5 Biology JOURNAL Birds in a Class of Their own MAin idea: Phylogenetic classification of organisms has revealed some surprising relationships. More will likely emerge as research and debate continue. Textbook pp. 30 31 Use Figure 1 below to answer questions 1 to 3. Class Amphibia Class Mammalia Class Reptilia Class Aves amphibians mammals turtles lizards and snakes crocodilians dinosaurs birds A common ancestor of all reptiles Figure 1 Phylogenetic tree showing traditional taxonomy 1. According to the Class names in Figure 1 above, are reptiles and birds in the same class? Explain. T / i 2. According to Figure 1, are birds more closely related to dinosaurs or to crocodilians? Explain. T / i LeArNINg TiP Taxa Names The name of the traditional taxonomic class for birds, Aves, is adapted from the Latin word for bird, avis. 3. According to Figure 1, the crocodile group of reptiles is more closely related to birds than to other reptiles. Should crocodilians be considered reptiles if they are genetically more closely related to birds than to other reptiles? If so, should birds also be considered reptiles? Explain your answers. T / i C A 4. Suppose you were revising this textbook in the year 2025. How many of the phylogenetic tree illustrations in this chapter would you expect to have to revise? Most? A few? None? Explain your answer. C A NEL 1.5 Biology Journal: Birds In a Class of Their Own 11
CHAPTER 1 Summary Understanding Biodiversity Biodiversity includes is evaluated by biological classification genetic diversity which result from species diversity structural diversity dichotomous key such as traditional taxonomy phylogeny hybridization evolutionary change organized by taxa including results in determination of clade shown by kingdom, phylum, class, order, family, genus, species phylogenetic tree resulting in kingdoms of life binomial nomenclature (genus & species) domains of life including including eubacteria, archaea, protists, fungi, plants, animals eubacteria, archaea, eukaryotes 12 Unit 1 Diversity of Living Things NEL
Chapter 1 Questions 1. Two plants that appear to be different species will sometimes breed with each other. What is this process called? (1.1) K/U (a) morphology (b) biodiversity (c) genetic diversity (d) hybridization 2. Clades are based on the most fundamental connection between species: their (a) evolutionary relatedness (b) morphology (c) taxon (d) domain (1.3) K/U 3. Indicate whether each statement is true or false. If you think the statement is false, rewrite it to make it true. (a) Carl Woese concluded that all organisms could be classified into six kingdoms based on differences in genetic makeup. (1.4) K/U K/U Knowledge/Understanding T / I Thinking/Investigation C Communication A Application (b) Most scientists consider birds to be a group of living dinosaurs. (1.5) K/U 4. Complete Table 1 below with details about the six kingdoms of life. (1.4) T / I Table 1 Kingdoms of Life Kingdom Prokaryotic or eukaryotic? Number of cells Example Eubacteria prokaryotic unicellular Salmonella Archaea Protista Fungi Plants Animals NEL Chapter 1 Questions 13
5. Explain why the creation of an accurate biological classification system for plants was necessary to ensure human health and success. (1.2) C A 6. Is morphology more important to traditional taxonomy or to phylogeny? Explain. (1.1, 1.2, 1.3) A 7. Fill in the Venn diagram below to compare birds and crocodilian reptiles. (1.5) A Birds Crocodilian Reptiles 8. Complete the bubble map below to show six properties of plants. (1.3) A reproduce sexually; sometimes asexually Plants cell walls composed of cellulose 9. Suppose your lab partner suggested that you attempt to classify a prokaryote using the biological species concept. How would you respond? Explain. (1.1, 1.3) A 14 Unit 1 Diversity of Living Things NEL