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Biology 11 Elgin Park Secondary 2016/2017 Name: _______________________ Block: ___ Teacher: _____________________ Room: _____ Biology 11 Teacher: Ms. Trevelyan Website : mrstrevelyan.com Office hours: Mondays, Wednesdays after school E-mail: [email protected] Room : 243C Welcome to Biology 11! Over the next few months, you are going to explore a world of science you’ve probably never experienced before! BIG IDEAS: Characteristics of Living Things All living things have common characteristics Process of Evolution Living things evolve over time. Taxonomy Organisms are grouped on the basis of identifiable similarities. Materials Covered 1. Scientific Method 2. Evolution 3. Taxonomy 4. Cells 5. Viruses 6. Bacteria 7. Plants 8. Animals EVALUATION Tests and Quizzes Assignments, labs Final Exam 45% 30% 25% TOTAL 100% CLASS EXPECTATIONS 1. Students are expected to arrive to class on time and be seated before the bell rings. If you are late, please wait outside the door until the teacher comes and lets you into the class. 2. Students are expected to attend class on a regular basis. If you miss a class for any reason, it is your responsibility to talk with your teacher on the day of your return to school so that you can collect missed work. If you miss a test, please bring a note signed by your parents/guardian explaining the reason for your absence. a. Late work with a valid excuse will be accepted for full marks b. Late work without a valid excuse that is handed in after the assignment has been marked and returned to students will be given a maximum of 50% of the mark. 2 3. Be respectful of your fellow students and your teacher. When someone is speaking, pay attention. Do not use cell phones or other electronic devices during lecture time or group work. 4. Please be aware that cheating and/or plagiarism will result in a mark of zero being assigned to all students involved. This includes sharing test questions/answers with other students who have not yet written the test, copying homework or lab work from another student, or copying information from the internet without giving your source proper credit. Your parents/guardians and the school administration will be notified. 5. Food and/or drink are not permitted during labs. This is for safety reasons! WHAT TO EXPECT FOR WORK LOAD Biology 11 is a senior science class. As such, it will have a heavier workload than any of the junior science classes you have experienced. This means you will probably have to do homework almost every night, and in addition may have to do some review too. There is a lot of vocabulary in Biology, so expect to have to learn a lot of new words. There is also a lot of reading. By the end of the course, you will have hopefully improved your skills to read and write in a scientifically precise and objective orientated manner. Biology 11 will also have many labs. You will be expected to attend these and participate. There will be some animal dissections, please inform the teacher right away if you are not comfortable with these for religious or personal reasons. It can be expected that every lab will have a lab report that must be handed in for marks. The ultimate goal of labs is to reinforce the course material and provide you with an opportunity to develop your lab skills. TEXTBOOK AND SUGGESTED SUPPLIES 3 ring binder Pencils Pencil crayons Rulers Calculator Glue sticks Pens Lots of lined paper Colored pens Biology 11 Textbook My textbook number is _____________________. FROM THE TEACHER There are a lot of exciting and interesting things to learn in Biology 11- I hope you enjoy the course!! I encourage you to try your best. If you do, I will always be willing to help you! Best Regards, Ms. Trevelyan 3 4 Building a Science Vocabulary! This is the longest word in the English language! What do you suppose it means? Do you think there are hints in the word itself? ____________________________________________________________________________ ____________________________________________________________________________ One challenge of biology to students is that it introduces a large number of new words. These words are used to name or describe living things and their parts, functions, and processes. In biology, many words are built from Greek and Latin terms that serve as root words Word roots can be added to other word roots. Prefixes can be added at the beginning of the word, and suffixes can be added to the end. In this way, words are produced which other biologists can understand, and which otherwise might take one or more whole sentences to express. The root cyto is a good example. It comes from a Greek word meaning hollow vessel. In biology, cyto always means cell. This gives rise to words like cytology. The suffix –ology means the study of. Therefore, cytology is the study of cells. On the next page is a list of some greek and latin root words commonly used in biological terms. You are NOT expected to memorize these! However, you might start to recognize some of these as you develop your vocabulary in biology. 1. 2. 3. 4. 5. dicephalosis is superior to monocephalosis gymnopodosis erythrocephalis postautocardosis rhinorrhea two heads are better than one barefootedness redhead after his own heart runny nose 5 ROOT WORK LIST: MEANING OF WORD ROOTS, PREFIXES, AND SUFFIXES USED IN BIOLOGY a, an without anemia ab away from abnormal ad, af near, toward adrenal, afferent alb white albumin algia pain neuralgia amphi both amphibious anti against antitoxin aqua water aquatic archae ancient Archaeopteryx arthr joint arthritis ase enzyme lipase auto self autobiography bi two or twice biceps bio life biology blast that which will germinate blastula brachi arm brachial card heart carditis carn flesh carnal caryo nucleus of a cell eucaryote cephalo head cephalothorax chloro green chloroplast chondr cartilage Chondrichthyes chromo color chromosome cide kill bactericide coel cavity coelom com, con with community costa rib intercostal cyst capsule nematocyst cyto, cyte cell leukocyte decid to cut off deciduous dendr tree dendrite dent, dont tooth denture, orthodontist derm skin epidermis di two diatomic dis, dys ill or bad disease eco household ecology ecto outer ectoderm ectomy removal appendectomy emia blood anemia endo inner endoderm enter intertine enteric epi on, at, beside epidermis erythro red erythrocyte eu true eucaryote ex out exterior fer bearer Rotifera gastro stomach gastric juice gen producing antigen gymno naked gymnosperm hemo blood hemoglobin herb non-woody plant herbarium hepato liver hepatic duct hetero other heterosexual homo, homeo same homogeneous hyper above, excessive hyperacidity hypo below, not enough hypothyroidism ia, iasis disease pneumonia ichthys fish ichthyology inter between interspecies intra within intraspecies iso same isoptera itis inflammation of appendicitis kin motion cytokinisis lac milk lactose leuco, leuko white leukocyte logy study of biology lysis dissolving cytolysis macro large macronucleus mal bad malnutrition mega very large megaspore meso middle mesophyll meta beyond or after metamorphosis micro small microbe mito thread mitochondrion mono one monoculture morpho shape, form morphology myo muscle myofibril nema thread nematocyst nephr kidney nephritis neuro nerve neurology oma tumor or swelling sarcoma omni all omnivore ophth eye ophthalmology orni bird ornithology ortho straight orthoptera osis act, condition acidosis osteo bone osteopath oto ear, otitis ovi, oo egg, oviduct oocyte para beside parathroid patho disease pathology ped, pod foot milliped peri around pericardium phago eating phagocyte pheno to show phenotype photo light photograph phyll leaf mesophyll phyto plant saprophyte pino to drink pinocytosis plasma form cytoplasm plast particle chloroplast poly many polysaccharide post after, behind posterior proto first protozoa pseudo false pseudopod pter wing diptera pulmo lung pulmonary renal kidney adrenal glands rhea, rrhea flow or discharge diarrhea rhino noserhinoceros sal salt saline sclero hard arteriosclerosis soma body chromosomes stom mouth stomata sym, syn binding together sympathy therm heat thermometer trop turn phototropic troph nourishment autotrophic viv living viviparous vore to devour carnivore xeros dry xerophyte zo animal zoology zyg united zygote 6 PART A: Your task is to analyse each of the following words with the help of a good dictionary. Separate each word into its parts, looking up and recording the meaning of each part. Then look up and record the meaning of the combined term. 1. biology 2. ecology 3. biosphere 4. autotrophic 5. heterotrophic 6. photosynthesis 7. saprophyte 8. carnivore 9. herbivore 10. omnivore 11. commensalism 12. bacteriophage 13. gametophyte 14. sporophyte 15. mesophyll 16. monocotyledonous 17. dicotyledonous 18. parthenogenesis 19. metamorphosis 20. ectothermic 21. endothermic 22. hypothalamus 23. leukocyte 24. erythrocyte 25. pericardium 7 PART B: The names at various levels of classification are often made up of Greek or Latin roots. Follow the same procedure as above with these terms: 1. Tracheophyta 2. Gymnospermae 3. Basidiomycetes 4. Ascomycetes 5. Chiroptera 6. Orthoptera 7. Porifera 8. Arthropoda 9. Coleoptera 10. Homoptera 11. Hemiptera 12. Hymenoptera 13. Echinodermata 14. Platyhelminthes 15. Rotifera 16. Osteichtyes 17. Chondrichthyes Part C: Now it is your turn. Using Greek or Latin root words, create four of your own biological terms! Word Definition 1. 2. 3. 4. 8 OVERVIEW: 1. Observation 2. Question 3. Prediction/ Hypothesis 4. Experimentation 5. Conclusion Review of the Scientific Method Science is ultimately based on observation (perceiving objects or events using one of the five senses). Observations often lead to questions, which lead to experiments to answer the questions. A prediction is an expected outcome. A hypothesis is a testable statement that proposes a possible explanation for an observation. You can make a hypothesis using a prediction. Formal hypotheses use an if (statement or relationship is true) then (you would expect a certain result) format. e.g. If Fertilizer A causes plants to grow, then plants given Fertilizer A will be taller than plants that do not receive it Fertilizer A is the independent variable; it is the thing being tested (goes on x-axis) Taller is the dependent variable, it is thing being measured (goes on y-axis) **The dependent variable depends on the independent variable** The hypothesis is then tested by experimentation. An experiment compares two groups: 1. Experimental Group- receives some kind of treatment (e.g. Fertilizer A) 2. Control Group- receives no treatment (e.g. no Fertilizer A) Everything about the two groups except the treatment you are testing must remain exactly the same. Why do you think this is? ____________________________________________________________________________ ____________________________________________________________________________ The variables that are kept the same are called controlled variables. Examples in this case include same temperature, same amount of water, same amount of sunlight for the treatment group and the control group. Collecting Data You can collect numerical data such as height in centimetres (quantitative data) or nonnumerical data such as red (qualitative data) Key terms: prediction Fertilizer A experimental If…then experimentation question observation hypothesis qualitative quantitative experiments independent taller dependent control 9 Quantitative data is usually organized into a table and/or graph. Draw a linear graph below using the data from the table. Remember to include a title and label the x-axis and y-axis. Day 1 Average height of Treatment (cm) 10 Average height of Control (cm) 7 5 25 15 10 45 20 15 60 35 20 68 45 treatment control Which form of data presentation do you find easier to read, the table or the graph? Explain why. ____________________________________________________________________________ ____________________________________________________________________________ Conclusion Scientists will examine the data to determine whether the hypothesis was rejected or accepted. Often, they use statistics to see if the difference between treatments was real or just happened by random chance. A large number of replications (30+) helps reduce errors in data. Technically, a hypothesis can be supported but never “proven” true. You would say, rather, you failed to reject your hypothesis if your data supported it. The conclusion should include: 1. A statement of the purpose of the experiment 2. If the hypothesis was accepted or rejected 3. Relevant data to support or reject #3, or if data was inconclusive 4. Any problems that occurred during experimentation 5. The next step in building on what was learned- future experiment(s) What is a Theory? A theory is an explanation for natural events that is based on a large number of observations. It is important to realize that theories explain what we observe. Theories must be falsifiable and, if new data does not support it, theories can be modified or changed. Example: the Germ Theory explains why we get sick and why we get infections. It uses observation of viruses and bacteria as well as data from those who get ill to create a theory on what causes the illness. Key terms: replication graph explanation accepted table Failed rejected Germ theory large modified falsifiable 10 The Scientific Method (aka the Process of Science) 1. Put the following steps of the scientific method in the proper order: ____ Organize and analyze the data ____ State the hypothesis ____ Identify the problem ____ State the conclusion ____ Design and carry out an experiment ____ Make an original observation ____ Ask a question 2. Match the term with its definition 1. Theory ____ A. Suggested explanation to a problem or observation based upon known information 2. 3. Law Hypothesis ____ ____ 4. Experiment ____ 5. Variable ____ 6. Control ____ 7. Data ____ B. Used to test a hypothesis C. Anything that can affect the results of an experiment D. Observations and measurements made during an experiment E. Part within the experiment that is maintained without change in order to provide a comparison for the part of the experiment containing the variable F. Many hypotheses that have been tested and supported by a great amount of evidence over a long period of time G. Statement describing (but not explaining) a natural event or phenomenon 8. Conclusion ____ 9. applicaiton ____ H. New use to which results are put or new technique developed I. A summary that explains whether or not the data support the hypothesis 11 3. A hypothesis statement may start with “if” (referring to cause), followed by the word “then” (referring to effect). For example: If I brush my teeth twice a day, then I can protect my teeth from decay. Complete the following hypothesis statements: a. If heat is applied to a liquid, then_______________________________________ b. If _____________________________________________ then living things in that ecosystem will be affected c. If a student misses many summer school classes, then _______________________ ___________________________________________________________________ d. If a wet rag is wrung out in outer space, then ______________________________ ___________________________________________________________________ 4. Develop a hypothesis for what may happen in the following situations: a. You have a long distance to travel when your gas needle signals empty Hypothesis: ________________________________________________________ __________________________________________________________________ b. The element on top of your stove is a bright red colour Hypothesis: ________________________________________________________ __________________________________________________________________ c. The soup you are eating is much too salty Hypothesis: ________________________________________________________ __________________________________________________________________ 5. The table below lists observations made of a candle, both before and after burning. Check QL for qualitative observation (characteristics) or QT for quantitative observations (measurements). Add a comment or explanation if you need to justify your choice. Observation 1. The candle is cylindrical in shape 2. It is 2 cm in diameter 3. The length is about 15 cm 4. The length decreases during the observation period 5. The candle is translucent 6. The last 2 mm of the wick glowed red QL QT Comment/Explanation 12 6. What can you conclude from the following graphs? Conclusion from table: Student’s Favourite Juices: _____________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Conclusion from table: Unemployment Rates: _____________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ 7. In the 1950’s scientists were running field experiments to compare three insecticides: Zap, Rid and KFB Formula 9 (KFB-9 for short). The scientists were employed by Y.U.K. Chemicals Inc., makers of Zap. They designed the field tests in order to see whether or not further research into the problem was necessary. The chemicals were sprayed on 3 separate fields and the experiment was repeated three times. Sometime after spraying, the scientists swept the area above the fields with large nets to capture any surviving flying insects. The bugs were counted and the table and graph that follows shows the data obtained from those field tests. Field Number Insecticide Used # of Surviving bugs found 1 Zap Trial 1 48 Trial 2 63 Trial 3 52 Trial 4 54.3 2 Rid 119 103 136 119.3 3 KFB-9 110 130 114 118 13 Comparing Average Effectiveness of 3 Insecticides 120 100 80 60 40 20 0 ZAP Rid KFB-9 a. Give one possible hypothesis for this experiment b. Why would some scientists argue that this was not a fair test? c. What factors must be controlled in this experiment? d. Do you think this was a controlled experiment? Why or why not? e. What is the conclusion for these results? 8. Think of a testable question you have and describe how you would design an experiment to test it. Question: __________________________________________________________________ Hypothesis: _________________________________________________________________ Treatment: ________________________________________________________________ Control: ___________________________________________________________________ Independent Variable: _______________________________________________________ Dependent Variable: ________________________________________________________ (Proposed) Conclusion: ______________________________________________________ 14 Unit 1: Process of Evolution Living things evolve over time. Evolutionary change: -role of DNA in evolution as a hereditary material -five agents of evolutionary change Mutation Genetic drift Gene flow Non-random mating Natural selection Development of the theory of evolution Lamarck Darwin Models of evolution Gradual change model Punctuated equilibrium model Speciation: -divergent evolution -convergent evolution -co-evolution e.g. flowers and pollinators Trends in complexity Body transport Gas exchange Cephalization Reproduction Symmetry Coelom Tissue development Vascularization Artificial selection and genetic modifications Plant and animal breeding Gene therapy and GMO’s Ethical considerations What is the role of DNA in evolution and biodiversity? What characteristics allow organisms to live in unique environments? How might the range of abiotic and biotic characteristics on Earth help us to understand space exploration (ex. Extreme environments…Mars or the moon?) What will the discovery of new fossils and genes reveal about the early evolution of plants and animals? 15 16 Section 1: CHARACTERISTICS OF LIVING THINGS Sometimes it is not easy to tell if something is alive e.g. fire-> “eats”, “grows”, needs oxygen, “dies”, but we know it is not living (it is in fact a chemical reaction) How do we define “living”? It must: 1. Respond to the environment e.g. poke- ouch! 2. Need energy (aka “food”) a. Plants are AUTOTROPHS and get food automatically using photosynthesis e.g. sunlight + CO2 + H2O C6H12O6 (sugar) + O2 b. Animals are HETEROTROPHS and obtain their food from other organisms e.g. eating other animals and plants 3. They grow e.g. baby child adult (bigger, more cells) 4. They reproduce -old organisms die and need to be replaced -some reproduce asexually (one parent producing a genetically identical offspring) -some reproduce sexually (two parents producing a genetically different offspring) -some species can do both! E.g. fungi 5. They must get rid of waste -animals sweat, feces, urine, CO2 6. They are made up of cells -viruses are NOT made up of cells! -cells are the building blocks of all living things -PROKARYOTIC cells are the most primitive and are lacking many structures -no membrane bound organelles (e.g. mitochondria, chloroplasts…) or nucleus -very small -include the Kingdoms Archaeobacteria and Eubacteria (bacteria) -EUKARYOTIC cells are more complex -have membrane bound organelles and a nucleus -bigger than prokaryotes -include the Kingdoms Animalia, Plantae, Fungi, and Protista Key terms: energy reproduce cells grow fire prokaryotic respond asexually heterotrophs sexually waste bacteria autotrophs eukaryotic 17 Review Questions- CHARACTERISTICS OF LIVING THINGS 1. How do autotrophs differ from heterotrophs? 2. How are prokaryotic cells different from eukaryotic cells? Which one are you made up of? 3. Which of the above characteristics do you think is most critical in defining a living organism? Explain why. 4. Viruses are in the “grey area” between living and non-living things. Research the characteristics of viruses and decide whether you categorize viruses as living or nonliving. Support your decision. 5. Movement is often used as a criteria to determine if an organism is living, but this is not always accurate. Explain why. 18 Section 2: DNA and Protein Synthesis Part I- The Nucleus and DNA: Control Centre of the Cell Every cell in your body has a specific _JOB__- but how do they become specialized? E.g. hair cells vs. skin cells vs. retina in the eye The _NUCLEUS_ in the cell contains the master set of instructions that tells the cell: a. what it will _DO (IT’S JOB) b. how it will function c. when it will _REPRODUCE_ and _GROW_ d. when it will die But how does the nucleus do this? How does it send messages to the rest of the cell? * The nucleus contains _DNA_, which carries the master set of _INSTRUCTIONS__for cell function * DNA (_DEOXYRIBONUCLEIC ACID__) is a double stranded helix that looks like a twisted ladder the sides of DNA are made of _SUGAR_ and _PHOSPHATE___ the steps of DNA are made up of 4 _BASES__: Adenine Cytosine Guanine Thymine Base Pairing Rules ADENINE (A) always pairs with __THYMINE_ (T) CYTOSINE (C) always pairs with _GUANINE_ (G) The bases in DNA are held together by weak HYDROGEN bond. These are cut apart by enzymes to allow for DNA REPLICATION and PROTEIN SYNTHESIS. Key terms: job phosphate instructions Guanine Protein synthesis grow hydrogen Cytosine sugar replication do Thymine dna bases Nucleus reproduce Deoxyribonucleic acid adenine 19 Part 2- The Role of DNA in Hereditary Traits and Evolution 1. DNA has many functions: A. DNA contains INSTRUCTIONS for all CELL FUNCTIONS and, therefore, DNA indirectly controls all of the functioning of all living things. B. DNA determines the HEREDITARY TRAITS of an individual C. DNA _EVOLVES__ (changes through mutations and recombination). This allows for new characteristics & abilities to appear which may help an individual to survive & reproduce. D. Self replication: DNA has the ability to make COPIES of itself 2. The arrangement of bases in DNA directs all cell activity -the bases are like letters that carry a message (_CODE_) -the code gives instructions for a specific task. 3. Genes are found on chromosomes A _GENE_is a small segments of DNA found at specific places on a chromosome that code for a protein. Each chromosome carries 1000s of genes! genes can vary in length from 100s to 1000s of BASES the arrangement of bases will decide what kind of protein is produced e.g. ACCATAGG makes protein “A” AGGCGTTA makes protein “B” only certain genes are _ACTIVATED_ in each type of cell. Depending which genes are active, different proteins are produced, and this causes cells to have different functions. E.x. You do not have skin pigment genes being used by your stomach cells ONE GENE ONE TYPE OF PROTEIN ONE FUNCTION 4. MUTATIONS can change DNA and affect protein structure and function If a mutation is beneficial and helps survival, it can lead to EVOLUTION! mutations are RARE, RANDOM and usually HARMFUL…more on this later! Key terms: Gene Cell functions instructions bases evolves evolution activated hereditary code mutations traits Copies 20 Section 3: Introduction to the Theory of Evolution Why is evolution important and relevant? Without evolutionary theory as a guiding framework, biology is just a collection of facts. “Seen in the light of evolution, biology is perhaps, intellectually the most satisfying and inspiring science. Without that light, it becomes a pile of sundry facts – some of them interesting or curious but making no meaningful picture as a whole.” Theodosiuos Dobhansky, 1973 What do we mean by the term evolution? 1. All species share a common ancestor. 2. Species have changed through time, ie they have adapted to different habitats. These 2 ideas are sometimes referred to as “descent with modification.” Today we sometimes use a more specific definition which refers to genetics: Evolution is … “A change in the frequency of alleles in a population over time.” We will study the 4 aspects of evolution, we will look at evidence for evolution, we will look at theories of evolution, how new species evolve, and finally patterns of evolution. Theories of evolution- Chp 15 pg. 376 (Lamark) and pg. 386, pg. 398 (Darwin) Evidence for evolution –Chp 15-3 pg. 382 – 385 Speciation –Chp 16-3 pg. 404-410 Patterns of evolution – pg 435- 439 Vocabulary Here are some terms that you should familiarize yourself with as we go through this unit: Evolution Theory Fossil Natural Selection Artificial Selection speciation Reproductive isolation Coevolution Fitness Struggle for existence Adaptation Survival of the fittest Descent with modification Behavioural isolation Geographical isolation Common descent Homologous structure Vestigial organ Directional selection Stabilizing selection Temporal isolation Adaptive radiation Disruptive selection Genetic drift Founder effect Convergent evolution Genetic equilibrium Allelic frequency Punctuated equilibrium Hardy-Weinburg principle Because evolution follows changes in the environment, to gain an appreciation of evolution it is helpful to review the changes that have occurred on earth since its formation 21 Section 3.1- A BRIEF OVERVIEW OF HISTORY OF LIFE ON EARTH 1. Formation of the earth’s__OCEANS__ and __ATMOSPHERE___ filled up. 2. Ancient atmosphere consisted of __CH4___, NH3, CO, CO2, N2, and H2O, but lacked free O2. There was intense ___LIGHTENING___and UV radiation. 3. Rocks 3.5 bya contain fossils of _ARCHAEOBACTERIA__. Organisms are heterotrophic absorbing organic molecules from surrounding water. Survived anaerobically (without_OXYGEN___) as photosynthesis had not yet occurred. 4. First photosynthetic eubacteria found. _OXYGEN__is produced. 5. Oxygen began to accumulate in the__ATMOSPHERE__. 6. Origin of aerobic metabolism and eukaryotes.__PROTOZOANS__, algae, fungi and simple, worm-like soft bodied animals evolved. 7. Animals with _HARD PARTS__(shrimp-like arthropods) evolved in the ocean. As well as primitive chordates (animals with backbones). 8. Invasion of land begins. _PLANTS_first and then lobe-finned fish. 9. Origin of__AMPHIBIANS_. 10. Major radiation of insects, amphibians, cone-baring plants, and reptiles with __AMNIOTIC__eggs evolve. 11. A few reptile lineages give rise to ___MAMMALS__ and dinosaurs. 12. Dinosaurs rule! 13. Mass __EXTINCTION__of Dinosaurs. 14. Mammals undergo adaptive radiation. Mammals found on all_CONTINENTS__. Key terms: Plants Lightening Oxygen extinction Mammals Amniotic Oxygen amphibians CH4 4.6 billion Hard parts oceans Protozoans Years ago Continents Amphibians Atmosphere archaeobacteria 22 Section 3.2- The Theory of Evolution is Born! Consider the following: 1. At one time, there was no life on Earth. Today, the Earth is full of living organisms 2. 99.9% of all organisms that ever existed are extinct 3. Organisms that exist today did not necessarily exist millions of years ago These concepts suggest that organisms have changed through time= EVOLUTION Where did the theory of evolution come from? Early time- 17th Century Most people believed in _CREATIONALISM__, which considered that all life was created just as it is now. Essentially, all plants and animals _APPEARED__ at the same time and have never changed. Creationism suggests that species are “_FIXED_.” Creationism also implies that earth itself also has never changed, mountains have always been _MOUNTAINS__ and the age of the earth is only about _10,000__ years old. These ideas were _NOT_ based on any evidence, but instead on a _BELIEF_. 18th Century Naturalists began systematic classification systems, especially _LINNAEUS_ (17071778). Many naturalists noticed that groups of organisms had similar __CHARACTERISTICS__, appeared to be _RELATED_ and appeared to be suited to their particular _ENVIRONMENT__. European naturalists travelled more widely and discovered more fossils, which clearly showed that organisms have _NOT_ always looked the same. _EXTINCTIONS_were also observed (eg the Dodo bird), so species were not “fixed.” 19th Century During this time, exploration and science flourished even further Lamarck, Wallace and Darwin developed theories about how a species can change over time Key terms: millions mountains extinctions Linnaeus appeared characteristics belief not No life theories 99.9 fixed environment theory 10,000 creationism 23 1. JEAN-BAPTISTE LAMARCK (1774-1829) Lamarck proposed animals evolve through inheritance of acquired characteristics (not true!). Suggested individuals capable of transforming through want/need For example, if a giraffe stretched his neck a lot, his neck would become longer and his offspring would inherit longer necks. 2. CHARLES DARWIN (1809-1882) and ALFRED WALLACE (1823-1913) In 1831, Darwin went on a voyage around the world on the HMS Beagle. The trip took 5 years! Darwin collected plant and animal samples and studied the new species etc. discovered on the journey Darwin noticed there was a pressure on organisms to survive and that the most well adapted organisms are more likely to survive and pass on their traits to their offspring. He coined the term NATURAL SELECTION to explain this process. It suggested that individuals were fixed and unchanging, and those well adapted survived and passed on their traits to their offspring. Darwin published a book called THE ORIGIN OF SPECIES in 1859 together with ALFRED WALLACE, who had developed the same theory of natural selection independently. 20/21st Century Discovery of the structure of _DNA_, ability to compare DNA and proteins of different organisms, and the information from _GENETIC_ studies support the theory of natural selection. Geologists prove the earth is about __4.6 BILLION_ years old, plenty of time for species to evolve. Key terms: HMS Beagle Natural selection DNA adapted Origin of species unchanging transforming pressure inherit genetic Alfred Wallace collected Pass on 4.6 billion 24 Acquired characteristics Review Questions- LAMARCK’S THEORY 1. Describe Lamarck’s three assumptions (see page 376) : a) Tendency towards perfection -all organisms have an inborn tendency toward complexity and perfection. They are continually changing and acquiring features that help them live more successfully. Ex. urge to fly flying birds b) Use and Disuse -if an organ or body part is used, it will change accordingly; if not used, it will decrease in size c) Acquired Traits -Lamark believed that acquired traits could be passed on (inherited) by offspring Why Life Changes According to Lamarck One of the earliest theories of change (evolution) was proposed by LAMARK. He observed that each kind of animal had ADAPTED to live efficiently in its environment. These adaptations occurred gradually, through time due to the way the animal USED its body parts. Those body parts not regularly used would DISAPPEAR because they were not needed for survival . (Law of use and disuse.) Lamarck explained evolution through INHERITANCE of acquired characteristics ie. Characteristics are passed on to the next GENERATION. For example: The giraffe is a leaf-eating animal The giraffe lives in regions where vegetation is not abundant and leaves are not near the GROUND. Giraffes have to STRETCH to reach the leaves. Through time this stretching would cause the neck and the front legs to ELONGATE. Changes in body shape caused by the way giraffes stretched their bodies was passed on to their OFFSPRING. Therefore, all future GENERATIONS would have these characteristics. At the same age, the YOUNG would have longer necks and legs than the previous generation. Keywords Stretch Young Disappear Ground Lamark 25 Used Generations Generation inheritance Offspring Elongate adapted Review Questions- DARWIN’S THEORY Describe the 5 points of Darwin’s Theory of Evolution (pg 386): 1. Individual organisms differ, and some of this variation is heritable 2. Organisms produce more offspring than can survive, and many that do survive do not reproduce 3. Because more organisms are produced than can survive, they compete for limited resources 4. Each unique organism has different advantages and disadvantages in the struggle for existence. Individuals best suited to their environment survive and reproduce, passing on their traits to their offspring, causing populatinos to change over time. 5. Species alive today are descended with modification from ancestral species that lived in the distant past. Why life Changes according to Darwin Charles Darwin recognized the importance of the TRAITS/CHARACTERISTICS Darwin observed much VARIATION within a species eg. the height of people. He also had read Malthus and realized that way more babies in most species were born than survived to adulthood The differences between individuals made it possible for some to be more SUCCESSFUL than others in finding food, escaping predators and ultimately surviving. This idea is called “NATURAL SELECTION.” If the environment CHANGES, natural selection will result in different individuals surviving. For example: The ancestors of modern day giraffes had SHORTER necks. Those ancestors had VARIATION within their population. Longer necked giraffes were able to reach the highest leaves where MORE food was available. Therefore, longer-necked giraffes were HEALTHEIR and able to produce more BABIES. The subsequent generation of giraffes had a HIGHER proportion of individuals with longer necks. The PROCESS occurred over and over again through thousands of generations until today giraffes have very long necks (but with the same number of vertebrae). Keywords Babies Variation Natural selection Traits/characteristics Environment 26 Shorter More Healthier Changes Successful higher Process Variation Section 3.3 EVIDENCE FOR EVOLUTION At this point (18th and 19th centuries) evolution meant: Organisms change over time Organisms have a common ancestor 1. FOSSILS Can be dated Older organisms are simpler in form than modern organisms show gradual series of changes in form Indicate that mass extinctions occurred 2. HOMOLOGOUS STRUCTURES Body parts of different organisms that on the surface look different, but anatomically are very similar. Often have different functions E.x. forelimbs of mammals (human, cat, whale, bat) Suggests that all mammals evolved from a common ancestor and that they adapted to different habitats. Fossils evidence has supported this idea. This process is called divergence. 3. ANALOGOUS STRUCTURES Body parts of different organisms that have similar functions and superficial appearance but very different anatomy. Ex. the flippers of penguins, sharks and dolphins Suggests that if 2 unrelated organisms occupy a similar environment then they will face similar selective pressures and will begin to look like one another. 4. VESTIGIAL STRUCTURES Structures with no current function, Are homologous to functional structures in related organisms. Ex. ear muscles and body hair in humans, remnant leg bones in whales Structure may have had a function in an ancient ancestor Over time the structures gradually disappear. Key terms: changes leg dated different similar 27 similar no extinction Common ancestor pressures function simpler disappear divergence 5. ARTIFICIAL SELECTION Rapid, heritable changes have been produced in domestic animals and plants by selectively breeding organisms with desired features. If differences as vast as those occurring between the Chihuahua and the Great Dane can be produced in a few thousand years of artificial selection by humans, it seems likely that much larger changes could occur in hundreds of millions of years. 6. MOLECULAR BIOLOGY Biological molecules such as proteins (amino acid sequence) or DNA (genetic code) can be compared between different organisms. The more similar the biological molecules, the more closely related the different organisms are 7. EMBRYOLOGY Embryology= the study of embryos (an unborn or unhatched animal) Embryos of many different kinds of animals look very similar and it is often difficult to tell them apart. Many traits of one type of animal appear in the embryo of another type of animal. E.x. fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth. This shows that the animals are similar and that they develop similarly, implying that they are related, have common ancestors and that they started out the same, gradually evolving different traits, but that the basic plan for a creature's beginning remains the same. Key terms: proteins similar larger domestic closely 28 embryology ancestors breeding traits DNA Desired features similar related EVIDENCE FOR EVOLUTION ASSIGNMENT Instructions: For this assignment, you will present images that illustrate evidence for evolution. Your pictures may be hand drawn or printed from the internet. They should be coloured and include a brief description of what they are showing and how this supports the theory of evolution. Images should include: 1. Fossils – Make a photo gallery of fossils that show: a. The oldest organisms are simple in form - check out the oldest fossils or fossils of the Cambrian period b. Organism change over time - this will require several images showing an organism changing over time - check out the Burgess shale fossils as a starting point c. There have been mass extinctions -find a fossil of a species that no longer exists today- like a dinosaur! 2. Homologous Structures -Find a picture illustrating homologous structures and colour the bones in the forelimb of each mammal 3. Analogous Structures -Find pictures of unrelated organisms with similar appearing body parts. Explain the origin of each organism. 4. Vestigial Structures -Find a diagram of a person showing at least 5 vestigial structures. State the original use of each structure. 5. Artificial Selection -Choose a domesticated animal to illustrate the numerous varieties of a single species. 6. Similarities in Embryology -find images of 3 organisms that look similar in the early stages of development You can present your images as a booklet, poster, or pamphlet. Give your assignment a title and be sure to include your name, block and date. Due date: _____________________ Total Marks: _________ 29 USING COMMON MOLECULES TO COMPARE SPECIES Examining the relationships between biological molecules, such as proteins or DNA can tell scientists how closely related organisms are. The more similar these molecules are, the more recently the organisms had a common ancestor. Follow the directions for each table. 1. There are 146 amino acids in the protein hemoglobin. This table shows a portion of the amino acid sequence for hemoglobin for 6 different mammals. Circle or highlight the amino acids in the chimp, gorilla, monkey, horse, and kangaroo sequences that differ from those in the human sequence. Amino Acid # Human Chimp Gorilla Rhesus Monkey Horse Kangaroo Amino Acid # Human Chimp Gorilla Rhesus Monkey Horse Kangaroo 2. 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 thr thr thr leu leu leu ser ser ser glu glu glu leu leu leu his his his cys cys cys asp asp asp lys lys lys leu leu leu his his his val val val asp asp asp pro pro pro glu glu glu gln leu ser glu leu his cys asp lys leu his val asp pro glu ala lys leu leu ser ser glu glu leu leu his his cys cys asp asp lys lys leu leu his his val val asp asp pro pro glu glu 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 asn asn asn asn asn asn phe phe phe phe phe phe arg arg lys lys arg lys leu leu leu leu leu leu leu leu leu leu leu leu gly gly gly gly gly gly asn asn asn asn asn asn val val val val val ile leu leu leu leu leu ile val val val val ala val cys cys cys cys leu ile val val val val val cys leu leu leu leu val leu ala ala ala ala ala ala his his his his arg glu The table shows the number of amino acids in cytochrome c that differ between several organisms and humans. Cytochrome c is a protein found in mitochondria. It is often studied because most organisms have mitochondria and therefore they have cytochrome c. Rewrite the information in the blank table by listing the organisms IN ORDER with the greatest number of differences at the top and the least at the bottom. Species Comparison Human—chimp Human—fruit fly Human—horse Human—pigeon Human—rattlesnake Human—red bread mold Human—rhesus monkey Human—screwworm fly Human—snapping turtle Human—tuna Human—wheat # of differences 0 29 12 12 14 48 1 27 15 21 43 Part IV Questions: Use all of the above tables to answer the questions below. 1. On the basis of hemoglobin similarity, which organism appears to be most closely related to humans? Least related? 2. On the basis of cytochrome c similarity, which organism appears to be most closely related to humans? Least related? 3. If the amino acids sequences in the proteins of two organisms are similar, why will their DNA also be similar? 30 Species Comparison 4. # of differences Many biologists believe that the number of differences between the proteins of different species indicates how long ago the species diverged from a common ancestor. Why do these same biologists believe that humans, chimps, and gorillas diverged from a common ancestor only a few million years ago? Section 3.4- EVOLUTION BY NATURAL SELECTION in FIVE STEPS STEPS: 1) Variation within a Species -Individuals within the species are not _IDENTICAL__ -Variation in colour, size, _SMELLING ACUITY (sharpness)_, RESISTANCE to disease, speed, allergies. 2) _Environmental Pressures/Changes_ Ex. Flooding, increase/decrease temperatures, predators, drought, lack of food, lack of space. 3) _ Differential Reproduction __ Selection occurs, you have babies or you don’t have babies Who selects? ….Nature or the _ENVIRONMENT_. 4) __Survival of the Fittest__ -Only some individuals get to reproduce and leave viable offspring, (VIABLE_-offspring that can have their own babies ie. Not _STERILE_) -Some traits (those that are NOT advantageous) _DISSAPEAR_ from the species. 5)_ Evolution Occurs _ -The next generation exhibits an increase in the frequency of the “best” traits. 31 Key terms: Differential Reproduction Sterile disappear Environment identical viable ability resistance smelling acuity Evolution Occurs Survival of the fittest Environmental Pressures/Changes HOMEWORK: Using the 5 Steps of Natural Selection explain how: 1. the length of the giraffe’s neck evolved. 2. the polar bear’s fur color evolved 3. the vocalizations of the killer whale evolved. Section 3.5 -THE SELECTION PROCESS BACKGROUND 1. Genetics Natural selection acts separately on each trait or characteristic of an organism. Every trait or feature of an organism is determined by at least one gene. Most organisms have 2 copies of every gene. E.x. eye color one gene that has 2 possible alleles or trait of a gene a blue allele (b) a brown allele (B). Typically, there is dominance between the different alleles so that person with: B B – brown eyes Bb – brown eyes bb - blue eyes Selection can change in frequency of a particular trait eg. eye color and or the frequency of a particular allele of a gene eg.”b” the allele for blue eyes. The % of a particular allele in a population is called allelic frequency. We use the term phenotype to describe the obvious characteristic or trait, while we use the term genotype to describe the combination of alleles. 2. The Bell Curve The bell curve refers to the shape of a graph that illustrates the normal distribution of traits in a population. Works for all traits E.x. foot length. When environmental conditions change a certain less common phenotype can become advantageous, as a result the curve can change or shift. 32 Populations do not decide to adapt, or mutate, after an environmental change. The phenotype has to already be there by chance; otherwise the population may become extinct. Natural selection can change the distribution of a trait along three paths: directional, stabilizing, or disruptive. Key terms: gene genotype decide characteristics dominance shape change phenotype allele Allelic frequency extinct shift distribution 3. THREE TYPES OF SELECTION a) Directional selection – causes a shift in a populations phenotypic distribution An extreme phenotype that was once rare is now common The mean value of a trait shifts in direction of the more advantageous phenotype b) Stabilizing Selection – the intermediate phenotype is favoured and becomes more common Decreases genetic diversity Extreme phenotypes may be lost c) Disruptive Selection – occurs when both extremes are favored and the intermediate are selected against. Intermediate forms are selected against Can lead to the formation of a new species Key terms: advantageous disruptive common against directional favoured shift stabilizing decreases Extremes 33 EXAMPLES OF SELECTION For each scenario below decide which type of selection is at work. Grass plants in Welsh Copper mines. Soil contaminated by copper from the mines is lethal to normal grass plants, but a chance mutation allowed one plant to grow. This plant prospered and reproduced, but only on the contaminated soil. On normal soil it grew more slowly than the normal plants and was easily out-competed. So now there are two varieties growing close together TYPE OF SELECTION: Pesticide Resistance Warfarin is a poison used to kill rats. When warfarin was introduced, some rat populations already contained rats with a chance mutation that gave them resistance to the poison. Without warfarin, stabilising selection favors normal rats – resistant rats are selected against, because they need a lot of vitamin K in their diet. Warfarin was a new environmental factor that killed normal rats. A few resistant rats survived, reproduced and passed on the resistance gene. They produced a new population of resistant rats. TYPE OF SELECTION 34 The Coelacanth. This fish species was known only from ancient fossils and was assumed to have been extinct for 70 million years until a living specimen was found in a trawler net off South Africa in 1938. So this species has not changed in all that time. TYPE OF SELECTION Bacterial resistance to antibiotics. Antibiotics kill bacteria, but occasionally a chance mutant appears that is resistant to that antibiotic. In an environment where the antibiotic is often present, this mutant has an enormous selective advantage since all the normal (wild type) bacteria are killed leaving the mutant cell free to reproduce and colonize the whole environment without any competition. Some farmers routinely feed antibiotics to their animals to prevent infection, but this is a perfect environment for resistant bacteria to thrive. The best solution is to stop using the antibiotic so that the resistant strain has no selective advantage, and may die out. TYPE OF SELECTION Sickle-cell anemia. People homozygous for this recessive allele usually die before reproducing. Their red blood cells contain abnormal hemoglobin which makes them become sickle-shaped and stick in their capillaries. People heterozygous for the allele should be at a disadvantage, because their red cells can sickle during exercise. However, people heterozygous for sickle-cell anaemia are more resistant to malaria than people homozygous for the normal allele. Where malaria is found, people heterozygous for sickle-cell have an advantage and are likely to survive, reproduce and pass on the allele. This produces populations with an equilibrium for numbers of people heterozygous for sickle-cell and non-carriers TYPE OF SELECTION The Peppered Moth (studied by Kettlewell). These light colored moths are well camouflaged from bird predators against the pale bark of birch trees, while rare mutant dark moths are easily picked off. During the industrial revolution in the 19th century, birch woods near industrial centers became black with pollution. In this changed environment the black moths had a selective advantage and became the most common color, while the pale moths were easily predated and became rare. TYPE OF SELECTION Birth Weight: In humans, birth weight can be represented by a typical bell curve. Babies of low weight lose heat more quickly (surface area to volume ratio) and get ill from infectious disease more easily, whereas babies of large body weight are more difficult to deliver through the pelvis. TYPE OF SELECTION Rabbit Fur Colour: Suppose there is a population of rabbits. The color of the rabbits is governed by two incompletely dominant alleles: black fur represented by “B” and white fur represented by “b”. A rabbit with genotype “BB” would have a phenotype of black fur, a genotype of “Bb” would have grey fur and a genotype of “bb” would have white fur. What type of selection 35 would occur if this population migrated to an area that has very dark rocks as well as white colored stone? TYPE OF SELECTION Homework: Choose an example of each type of selection, and draw the appropriate graph to illustrate the example. Make sure to label the axes. Section 3.6- MECHANISMS OF EVOLUTION -evolution occurs at the population level, with genes as the raw material -a non-changing population is said to be in genetic equilibrium -there are 5 mechanisms that cause a population to change, potentially leading to evolution. These are: natural selection, genetic drift, gene flow, mutation, and non-random mating -Hardy and Weidnberg proved mathematically that evolution will not occur in a population unless allelic frequencies are acted upon by forces that cause change= Hardy-Weinberg principle -there are 5 conditions for the Hardy-Weinberg principle to work: 1. there must be no genetic drift (less likely in larger populations) 2. there must be no gene flow (no immigration or emigration) 3. there must be no mutations 4. mating must be random 5. there must be no natural selection (all individuals are equally adapted to the environment) -hardly any population meets all of these 5 principles in the “real world” (unlike computer programs) 1. Genetic Drift -any change in allelic frequency in population due to chance -in larger populations, genetic drift is averaged out; in smaller populations, genetic drift may lead to the loss of an allele all together Two extreme examples of genetic drift are: a. Founder Effect: when a small sample of a population settle in a separate location and this leads to large genetic variation between the separated populations 36 b. Bottleneck: this is when a population declines to a very low number and then rebounds, often having reduced variability because it originated from a low number of individuals Key terms: ‘real world’ allele mechanisms population random Large conditions declines equally founder bottleneck chance equilibrium Hardy and Weidnberg 2. Gene Flow -few populations are isolated- there are individuals moving in and out of a population -the random immigration and emigration of individuals increases genetic variation within a population and reduces differences between populations 37 3. Non-random mating -organisms usually mate with individuals in close proximity. -there may also be selectivity among mates (strongest/fastest/brightest colours etc) -this may lead to inbreeding, which could lead to a change in allelic proportions favouring individuals that are homologous for particular traits 4. Mutation -a gene mutation is a RANDOM insertion, deletion or substitution of bases in the DNA code -a chromosomal mutation is a deletion, duplication, inversion, or translocation of an entire chunk of a chromosome -mutations are usually harmful, but if beneficial, a mutation may lead to a change in allelic frequencies 5. Natural Selection -acts to select the individuals that are best adapted for survival and reproduction -acts on an organisms phenotype (visible physical traits) and changes allelic frequencies -can occur through stabilizing selection, directional selection, and disruptive selection -a fourth type, called sexual selection, is also considered a type of natural selection Key terms: selectivity beneficial moving increases adapted frequencies gene isolated Chromosomal proximity inbreeding reduces phenotype 38 Section 3.7 MODELS OF EVOLUTION -Gradualism and punctuated equilibrium are two ways in which the evolution of a species can occur. -A species can evolve by only one of these, or by both. -Scientists think that species with a shorter evolution evolved mostly by punctuated equilibrium, and those with a longer evolution evolved mostly by gradualism. 1. Gradualism Slow change over time with no rapid periods Continuous series of small mutations Intermediary forms showing gradual change Can take a long time 2. Punctuated Equilibrium Rapid change interspersed with long periods of no change Fewer, bigger mutations No intermediary forms Questions 1. Bacteria are prokaryotic cells with relatively small genomes that can reproduce in as little as 20 minutes under favourable conditions. Suppose a bacterium had a mutation that made it resistant to an antibiotic drug. What model of evolution does this demonstrate? 2. Give an example of evolution that demonstrates gradualism. 39 Keywords longer both ways rapid small Long time shorter no intermediary No rapid 40 Section 3.8 DIFFERENT PATTERNS OF EVOLUTION Factors such as environment and predation pressures can have different effects on the ways in which species exposed to them evolve. As a result, evolution over time can follow several different patterns. These include three main types of evolution: divergent, convergent, and parallel evolution. 1. Divergent Evolution (see “A”) occurs when one species diverges into multiple descendant species. Darwin's finches are an example of this. Aka adaptive radiation 2. Convergent Evolution (see “B”) occurs when species have different ancestral origins but have developed similar features. Example: sharks and porpoises (dolphins too!) 3. Parallel Evolution (see “C”) Occurs when species have a common ancestor and develop similar features Example: Wooly Mammoth and modern elephant Another pattern observed is Coevolution. Coevolution occurs when two species influence each other during evolution. For example, an insect may evolve specialized parts that allow it to feed on a specific flower, whereas the flower evolves to facilitate pollination by that particular insect. 41 Keywords parallel B divergent coevolution adaptive ways C convergent patterns similar influence different A Section 4: Artificial Selection and Genetic Modifications In the past, humans developed the skills to selectively breed plants and animals to suit their needs. The gray wolf, for example, was bread to assist humans with herding animals, hunting, and for companionship. This human-lead process of selective breeding is called artificial selection. Artificial selection of the gray wolf ultimately lead to the development of the many breeds of dogs that exist today. Artificial selection differs from natural selection in several ways: 42 One the ethical concern for artificial selection is that organism are modified for human gain rather than to the benefit of the species. Bull dogs, for example, have been bred to have such large heads that pregnant bull dogs often need caesarians to be able to give birth successfully. Keywords artificial benefit dogs selectively companionship caesarians gain natural Recently, scientists have developed the technology to isolate and modify the genetic code of life, DNA. This has enabled them to develop genetically modified organisms. The process of building a genetically modified organism are as follows: 43 What are some of the Uses for Genetic Engineering? Grow human hormones in bacteria cultures Make artificial sweeteners using bacteria Study human diseases by inserting human DNA into mice Replace incorrect DNA sequences and cure genetic diseases Replace harmful bacteria on plants with non-harmful bacteria Use nitrogen bacteria in the soil & plants to make fertilizer Improve transport of fruits by extending the time it takes for them to ripen Create plants and animals that are resistant to diseases Increase protein production of cells ex. Insulin for diabetics Assist in human reproduction by fixing broken genes in the egg/sperm Assist in human organ transplants by reducing rejection of the organ by the host What are some concerns around Genetic Engineering? Introduced genes may escape into non-modified organisms ex. Cross pollination of GM plants with non-GM plants Pesticide resistant crops may cause excessive use of pesticides People with allergies may inadvertently be exposed ex. Eat a tomato with a peanut gene 44 45 Section 5: Trends in Complexity As we continue learning in this course, we will be taking a closer look at trends in complexity in the evolution of life. In particular, we will focus on the following. Body transport o How do organisms transport materials inside the body? o Diffusion? Osmosis? Transport vessels? Gas exchange o How do organisms obtain oxygen? o How do organisms release carbon dioxide? o How does this process change as organisms move from water to land and become larger? Cephalization o Why is the development of a head so important? o What advantages does having a brain bring to the table? Reproduction o What form is used? Asexual? Sexual? Both? o How does this connect to the type of environment lived in by the organism? Symmetry o Radial? Bilateral? Non-uniform? o How does symmetry connect to the type of environment lived in by the organism? o How does symmetry affect mobility? Coelom o Does the organism have a coelom? Pseudocoelom? None? o Why is the coelom so important? Tissue development o Does the organism have tissue? How many layers? Vascularization o Does the organism have a blood vessel syste 46