Life Science 11 Introduction to Biology PDF

Life Science 11 Introduction to Biology Learning Guide #1 ANSWER KEY Use your textbook (Miller-Levine “Biology” 5th edition – Chapter 1) or the online textbook (...

Life Science 11 Introduction to Biology Learning Guide #1 ANSWER KEY Use your textbook (Miller-Levine “Biology” 5th edition – Chapter 1) or the online textbook (https://openstax.org/books/biology-2e/pages/1-introduction) and the Unit 1 notes posted on my website (https://sites.google.com/site/demonbiology/biology) to complete the following review. Introduction to Biology Science is a special way of looking at / learning about the world around us. a. Looks into relationships between things and events. b. Tries to explain/understand those relationships by collecting information. c. Tests the explanation to see if it holds up under experimentation/various circumstances. The Scientific Method The Scientific Method is an organized way of figuring something out. There are usually six parts to it and they are completed in this order: 1. Question/Observation: What do you want to learn/investigate? An example would be, "What doorknob in the mall has the most germs?" or "Do girls have faster reflexes than boys?" or "Does the color of a light bulb affect the growth of grass seeds?" 2. Research: Improve your knowledge/understanding on the topic. Look for information in books, on the internet, and by talking with experts to get the most information you can. 3. Hypothesis: After doing your research, predict the answer to your question. Another term for hypothesis is make an educated guess. This is usually stated like "If...(do something) then...(this will occur)" An example would be, "If grass seeds are grown under green light bulbs, then they will grow faster than plants growing under red light bulbs." 4. Experiment: Test your hypothesis. In our example, you would set up grass seeds under a green light bulb and another set of grass seeds under a red light bulb observing each for a set time period. You would also set up grass seeds under regular white light so that you can compare it with the others. This is known as the control group. Life Science 11 Introduction to Biology Learning Guide #1 Remember, all other factors (constant factors) must be controlled. Constant factors for the seed experiment would include the amount of light exposure, water, fertilizer, etc. Each step of the experiment must be recorded so that others may perform the same experiment. 5. Conclusion: Review and analyze the data and check to see if your hypothesis is correct. If the grass under the green light bulb grew faster, then you have proved your hypothesis, if not, your hypothesis is wrong. It is not "bad" if your hypothesis is wrong, because you still discovered something! 6. Publish/Repeat: Experiments must be repeatable. If another scientist performs the same experiment, following the same procedure, they should obtain the same results/conclusion. Characteristics of a Valid Scientific Experiment Part of the Scientific Method involves designing experiments which will test the hypothesis. These experiments are based on the testable prediction. Although the design of the experiments varies considerably, most include the following characteristics: 1. An experimental variable: This can also be referred to as the independent variable. It is the factor being tested and there should only be one in an experiment. 2. A dependent variable: Also called the responding variable. It is the factor that is being observed as it responds to the experimental variable. 3. One or more experimental groups: Groups within the experiment in which the experimental variable is varied. 4. A control group: Provide a basis for comparison the results with the experimental group. Every experiment must have a control group. 5. Constant factors: These are factors that are kept constant. These include all factors except for the experimental variable. 6. Large sample size: This ensures that results are valid/verified. 7. Repeatable: If it is not repeatable then the results would be invalid as there would be no way to check them. Life Science 11 Introduction to Biology Learning Guide #1 What is a Theory? Most explanations for biological processes are in the form of Theories. Theories are hypotheses which have survived extensive repeated testing. Theories are subject to revision/modification as new information is gathered. You can never say that a theory is correct. You can say a theory is supported. Questions: 1. Why is the scientific method used and why is it important? The scientific method provides a reliable answer to a hypothesis and by using a logical sequential series of steps during an investigation. 2. Johnny has handed you a lab report. How can you determine if Johnny’s experiment is valid? Repeat the experiment. If valid the results/conclusion should be the same. 3. Name and describe the main 2 types of variables. Independent Variable (x): This is the variable that we control/change to test the effects on the dependent variable. Dependent Variable (y): This variable is the variable being observed. The dependent variable is "dependent" on the independent variable. 4. You observe that grass seems to grow better in soil than it does in gravel. Design a scientific experiment to test this. What is the independent variable? What is the dependent? Independent Variable (x): soil type Dependent Variable (y): Grass growth (height) Plant grass in different soil types, keep all other factors (water, light, time, etc.) constant Measure grass height. 5. Compare and contrast a fact and a theory. Give an example of each Facts are observations; theories are the explanations to those observations. Evolution is a fact. The explanation that evolution occurs by Natural Selection is a theory. Life Science 11 Introduction to Biology Learning Guide #1 Safety in the Laboratory 1. Why might eating or drinking in the laboratory be dangerous? Food or drinks may be contaminated due to chemical / pathogen exposure in the lab. 2. Look around the room. What safety equipment do you recognize? What is their function? Fire Extinguisher - put out fires Fire Blanket - smother flames Eye wash - flush unwanted substance from the eyes Safety shower - wash away any chemical exposure Safety glasses / goggles - protect eyes from exposure to dangerous substances Broken glass container - protect custodial staff from broken glass in garbage Fume hood - protect from harmful fumes produced during reactions 4. What is the most important rule in the laboratory? Follow all safety instructions Living Things Biology is the study of life. But what is life? In general, biologists agree that all living things have 6 main characteristics. Of course, some non-living things can have these traits. But only living things have all of them. 1. Organized/Made of Cells ▪ The basic unit of life is the cell. All organisms are composed of one or more cells. Multicellular organisms may have their cells organized into tissues, organs and organ systems. 2. Feeding / Obtain and Use Energy ▪ All living organisms need to take substances from their environment to obtain energy to grow and to stay healthy. Green plants produce glucose and oxygen from carbon dioxide, water, and sunlight. This process is called photosynthesis. ▪ Animals and other organisms that do not contain chlorophyll, heterotrophs produce their own food. They rely on plants or other organisms. Life Science 11 Introduction to Biology Learning Guide #1 ▪ To perform these processes living organisms must exchange gases with their environment. This process is called respiration. ▪ Animals take in oxygen and expel carbon dioxide, a waste product. ▪ Humans also produce urine,a liquid waste which is a result of the body’s metabolic processes and which must be expelled from the body. 3. Respond to Stimuli/Movement ▪ All living things can respond/react to changes in their internal or external environment. These changes in are called stimuli. ▪ Examples include changes in light, temperature, or sound. ▪ All organisms respond to change. The response to changes in the internal environment is called homeostasis. ▪ All living organisms move in one way or another. All living organisms have internal movement, the ability of moving substances from one part of their body to another. Some living organisms show external movement as well, they can move from place to place by walking, flying or swimming. Examples of movement in plants are the bending towards the light, and water moving up from the roots. Movement of animals from one place to another is called locomotion. 4. Growth and Development ▪ When living things feed they obtain energy. Some of this energy is used for growth. Living things become bigger and more complex as they grow. ▪ During their life organism undergo changes in how their body works or is organized. For example, metamorphosis refers to a process by which caterpillars change into butterflies. In humans, an analogous process is called puberty. 5. Reproduction ▪ All living things reproduce. Humans make babies, cats produce kittens and pigeons lay eggs. Plants also reproduce. Many plants make seeds which can germinate and grow into new plants. This is not necessary for the survival of an individual organism, but it is necessary for the survival of the species. ▪ Note: This does not mean that all organisms reproduce sexually, some organisms have methods of reproduction that only involve one parent. Life Science 11 Introduction to Biology Learning Guide #1 6. Evolution Populations change over long periods of time. Questions: 1. Define biology? In your opinion, why is it important? The study of life. (Any logical opinion is acceptable.) Example, humans are living things, therefore when we study biology, we are also studying ourselves and the interactions that other living things have with us. This understanding may be important for the survival of our species. 2. Biologists study living things and their surroundings. Identify at least 3 careers for a biologist. Any 3 careers. Ex: Ecologist, Botanist, Zoologist, Ichthyologist, etc. 3. There is said to be unity and diversity amongst all living things. Explain what is meant by this phrase. All living things are different from each other, but all share basic characteristics. Language of Biology Students may find it difficult to understand science is because of all the hard to write, spell and read words. Scientific vocabulary is a hodge-podge of “little words” that are linked together to have different meanings. If you learn the meanings of the little words, you will find scientific vocabulary much easier to understand. Use the list provided on my website to identify the “little words” and guess the meaning of each of the terms. 1. Cytology (Cyt- “cell”; -logy “study of”) study of cells 2. Protozoa (Proto- “first”; zoa “animal”) first animals 3. Epidermis (epi- “on; upon”; derm “skin” top layer of skin 4. Abiotic (a- “not”; bio “life”) non-living 5. Dermatitis (derm- “skin”; -itis “inflammation of”) inflammation of the skin 6. Hemophilia (hemo- “blood”; -philia “loving”)blood loving (a condition where the blood does not clot) 7. Anaerobic (an- “not”; aer “air or oxygen”) non oxygen requiring 8. Bilateral (Bi- “two”; latera “sides” having two sides 9. Arthropod (arthro- “joint”; -pod “foot”) jointed feet 10. Photosynthesis (photo- “light”; synthesis “to put together”) using light to join things together 11. Heterotroph (hetro- “others”; -troph “feeder”) feed on others 12. Encephalitis (Encephalo- “brain”; -it is “inflammation of”) inflammation of the brain 13. Macrophage (Macro- “large”; -phage “eater” eater of large things 14. Neuralgia (Neuro- “nerve”; -algia “pain”) nerve pain 15. Histology (histo- “tissue”; -ology “study of”) study of tissues Life Science 11 Introduction to Biology Learning Guide #1 Microscopes 1. What is the proper way to carry a microscope? Always carry the microscope with both hands. Grasp the arm of the microscope with one hand and place your other hand under the base. 2. What is the purpose of the objectives? magnifies the images of the specimen to form an enlarged image 3. What is the diaphragm on the microscope used for? Wheel-shaped device that regulates the amount of light passing through the specimen 4. What is the difference between the fine and coarse adjustments? Coarse adjustment knob for larger changes in focusing & Fine adjustment knob for precision focusing 5. What part of the microscope produces the light? Lamp (light source) 6. What parts are in the body of the microscope? Eyepiece, body tube, and lenses 7. What is the total magnification power of your microscope under the following operating conditions? OBJECTIVE OCULAR TOTAL MAGNIFICATION (X) FOV DIN 4 10 x 40X 5mm = 5000m DIN 10 10 x 100X 2mm = 2000m DIN 40 10 x 400X 0.5mm = 500m 8. If your microscope lens is dirty what should you use to clean it? Lens paper. 9. What happens to the light intensity as you adjust the diaphragm? Explain your answer. Light intensity changes. The diaphragm controls the amount of light reaching the specimen on the stage. 10. Explain why a specimen viewed with a compound light microscope must be very THIN. Light must be able to travel through the specimen to reach the lenses above. Life Science 11 Introduction to Biology Learning Guide #1 11. Given that the low power field is 5 mm, the medium power field is 2 mm and the high power field is 0.5 mm, answer the following: mm m 1 An object covers ⁄10 of the high power field. How big is the object? 0.05 50 An object covers 1⁄15 of the low power field. How big is the object? 0.4 400 An object covers 1⁄5 of the medium power field. How big is the object? 0.4 400 Use the microscope formulae to work out magnification problems. Show all your work. 12. An organism occupies 1⁄2 of the medium power field. a. How long is it in micrometres? 𝑺𝑨𝑺 = 𝟏⁄𝟐 (𝟐𝟎𝟎𝟎𝝁𝒎) = 𝟏𝟎𝟎𝟎𝝁𝒎 b. If a drawing was made of it 10 cm long, what would the drawing magnification be? 𝟏𝟎𝟎𝟎𝟎𝟎𝝁𝒎 𝑫𝒓𝒂𝒘𝒊𝒏𝒈 𝑴𝒂𝒈𝒏𝒊𝒇𝒊𝒄𝒂𝒕𝒊𝒐𝒏 = = 𝟏𝟎𝟎𝑿 𝟏𝟎𝟎𝟎𝒖𝒎 13. The actual size of an organism is 200 micrometres, and you have made a drawing of it 15 cm. What is the drawing magnification? 𝟏𝟓𝒄𝒎 𝟏𝟓𝟎𝟎𝟎𝟎𝝁𝒎 𝑫𝒓𝒂𝒘𝒊𝒏𝒈 𝑴𝒂𝒈𝒏𝒊𝒇𝒊𝒄𝒂𝒕𝒊𝒐𝒏 = = = 𝟕𝟓𝟎𝑿 𝟐𝟎𝟎𝒖𝒎 𝟐𝟎𝟎𝒖𝒎 14. An organism stretched across 1⁄5 of the high power field. c. How long is it in micrometres? 𝑺𝑨𝑺 = 𝟏⁄𝟓 (𝟓𝟎𝟎𝝁𝒎) = 𝟏𝟎𝟎𝝁𝒎 a. If a drawing was made of it 10 mm long, what would the drawing magnification be? 𝟏𝟎𝒎𝒎 𝟏𝟎𝟎𝟎𝟎𝝁𝒎 𝑫𝒓𝒂𝒘𝒊𝒏𝒈 𝑴𝒂𝒈𝒏𝒊𝒇𝒊𝒄𝒂𝒕𝒊𝒐𝒏 = = = 𝟏𝟎𝟎𝑿 𝟏𝟎𝟎𝒖𝒎 𝟏𝟎𝟎𝒖𝒎 15. An organism when viewed under the low power, will fit into the diameter of the field 14 times. 𝟓𝟎𝟎𝟎𝝁𝒎 d. How long is it in micrometres? 𝑺𝑨𝑺 = = 𝟑𝟓𝟕𝝁𝒎 𝟏𝟒 a. A drawing was made and labeled 30X. How long is the drawing? 𝑫𝒓𝒂𝒘𝒊𝒏𝒈 𝑺𝒊𝒛𝒆 = (𝟑𝟎𝑿) × (𝟑𝟓𝟕𝝁𝒎) = 𝟏𝟎𝟕𝟏𝟎𝝁𝒎 = 𝟏𝟎. 𝟕𝟏 𝒎𝒎