Biology in the 21st Century Answer Key SECTION 1. THE STUDY OF LIFE 1. forest, desert, grasslands, oceans, lakes, nose interior, human skin 2. moray eel, snout beetle, polar bear, orchid, honeypot ants 3. biosphere 4. species 5. biodiversity 6. Circle: need energy, made up of one or more cells, can reproduce, react to environment. Cross out: ability to feel pain, need sunlight, produce seeds, need to sleep, can move. 7. one cell 8. energy 9. dividing 10. genetic material 11. a 12. c 13. d SECTION 2. UNIFYING THEMES OF BIOLOGY 1. biosphere 2. ecosystem 3. organism 4. cell 5. process information 6. enable chemical processes 7. carry an organism 8. pumps blood throughout the body 9. grind food 10. temperature, blood sugar, acidity 11. temperature 12. cells 13. negative 14. changing, stable 15. true 16. false 17. system 18. ecosystem 19. adaptation 20. evolution 21. homeostasis SECTION 3. SCIENTIFIC THINKING AND PROCESSES 1. observing 2. forming hypotheses 3. testing hypotheses 4. analyzing data 5. evaluating results 6. making observations 7. evidence 8. sights 9. sounds 10. smells 11. mass 12. volume 13. temperature 14. dependent variable: blood pressure, independent variable: medication 15. dependent variable: cellular respiration; independent variable: temperature 16. dependent variable: seed germination; independent variable: precipitation 17. watching the migration patterns of storks 18. adding a solid to a liquid to find out if the solid will dissolve 19. false 20. true 21. condition that is changed by a scientist 22. data 23. conclusion 24. condition that does not change SECTION 4. BIOLOGISTS TOOLS AND TECHNOLOGY 1. LM 2. SEM 3. TEM 4. MRI 5. a 6. d 7. true 8. false 9. false 10. genomics Holt McDougal Biology i Biology in the 21st Century
continued 11. microscope 12. molecular genetics 13. gene SECTION 5. BIOLOGY AND YOUR FUTURE 1 3. Answers will vary but should include ways that biology affects a person s health. 4 6. Answers will vary but should include ways that biology affects the world around us. 7. Benefits: the development of transgenic organisms that can be used for medical treatments, insect-resistant crops, genetic screening for and early diagnosis of diseases 8. Risks/ethical concerns: privacy of genetic information derived from screening, the possibility that people might try to genetically engineer ideal children or choose the characteristics of their children 9 11. Answers will vary but should include biological topics that students would like to know more about. 12. c 13. b Holt McDougal Biology ii Biology in the 21st Century
Section 1: The Study of Life KEY CONCEPT Biologists study life in all its forms. VOCABULARY biosphere biology metabolism biodiversity organism DNA species cell MAIN IDEA: Earth is home to an incredible diversity of life. forest polar bear snout beetle honeypot ants ocean lake human skin nose interior moray eel orchid desert grassland Use the phrases in the box above to fill in the chart below. 1. In the box labeled The Biosphere, list examples of environments on Earth in which life is found. 2. In the box labeled Species, list examples of species that can be found on Earth. Earth is home to an incredible diversity of life. The Biosphere Species Fill in the blank with the word or phrase that best completes the sentence. 3. The even includes places such as your eyelashes, pools of hot, acidic water in Yellowstone National Park, and cold, windswept rocks in the Aleutian Islands. 4. Members of a should be able to reproduce together. 5. In places where is high, there are more species. Holt McDougal Biology 1 Biology in the 21st Century Section 1: The Study of Life
continued MAIN IDEA: All organisms share certain characteristics. 6. In the box below, circle the four items that are characteristic of all living organisms. Cross out the items that are not characteristics of all living organisms. need energy need sunlight can reproduce made up of one or more cells produce seeds can move ability to feel pain need to sleep react to environment Circle the word or phrase that best completes the sentence. 7. The most common organisms on Earth have one cell / more than one cell. 8. Animals need energy / DNA in order to build up or break down materials. 9. Cells reproduce by dividing / combining. 10. When organisms reproduce, they pass on their metabolism / genetic material. Vocabulary Check Choose the answer that best completes each sentence. 11. All organisms store their genetic material in a. DNA. b. cells. c. species. d. metabolism. 12. An organism is a. a type of species. b. an environment in the biosphere. c. any individual living thing. d. the basic unit of life. 13. The scientific study of all forms of life is called a. geology. b. chemistry. c. physics. d. biology. Holt McDougal Biology 2 Biology in the 21st Century Section 1: The Study of Life
Section 2: Unifying Themes of Biology KEY CONCEPT Unifying themes connect concepts from many fields of biology. VOCABULARY system homeostasis adaptation ecosystem evolution MAIN IDEA: All levels of life have systems of related parts. Using the words in the box, fill in the outline with the basic systems of life. more complex 1. 2. 3. 4. less complex organism biosphere cell ecosystem MAIN IDEA: Structure and function are related in biology. Match each body part with its specialized function. 5. brain cells carry an organism 6. enzymes process information 7. feet pumps blood throughout the body 8. heart enable chemical processes 9. teeth grind food Holt McDougal Biology 3 Biology in the 21st Century Section 2: Unifying Themes of Biology
continued MAIN IDEA: Organisms must maintain homeostasis to survive in diverse environments. 10. Circle the conditions that are regulated by homeostasis. temperature outside environment blood sugar acidity thoughts Circle the word or phrase that best completes the sentence. 11. Humans shiver in response to cold because of the body s attempts to maintain an even temperature / acidity. 12. Homeostasis is important because behaviors / cells need certain conditions in order to function. 13. The body usually uses positive / negative feedback to maintain homeostasis. 14. The conditions outside the body are always the same / changing, but the conditions inside the body are generally very changeable / stable. MAIN IDEA: Evolution explains the unity and diversity of life. Choose whether each statement is true or false. 15. true / false All living species evolve and change over time. 16. true / false Adaptation occurs when you get cold and put on a coat. Vocabulary Check Match the words with their meanings. 17. organized group of related parts that interact to form a whole 18. physical environment with different species that interact with each other and with nonliving things 19. an inherited trait that gives an advantage to individual organisms and is passed on to future generations evolution adaptation homeostasis 20. the change in living things over time ecosystem 21. the maintenance of constant internal conditions in an organism system Holt McDougal Biology 4 Biology in the 21st Century Section 2: Unifying Themes of Biology
Section 3: Scientific Thinking and Processes KEY CONCEPT Science is a way of thinking, questioning, and gathering evidence. VOCABULARY observation hypothesis independent variable constant data experiment dependent variable theory MAIN IDEA: Like all science, biology is a process of inquiry. Use the following words or phrases to fill in the blanks in the flow chart. forming hypotheses observing testing hypotheses evaluating results analyzing data 1. Scientists make observations and examine prior research. 5. Scientists evaluate data and conclusions presented by other scientists. 4. Scientists analyze their data to draw conclusions about their research. 2. Scientists ask questions and try to explain observations. 3. Scientists collect data that they use to support or reject a hypothesis. Circle the word or phrase that best completes the sentence. 6. A scientist begins his or her research by making observations / forming theories. 7. Scientists make observations and do experiments as a way to gather variables / evidence. Holt McDougal Biology 5 Biology in the 21st Century Section 3: Scientific Thinking and Processes
continued Fill in the chart using the words from the box. sights volume temperature mass sounds smells Qualitative data 8. 9. 10. Quantitative data 11. 12. 13. MAIN IDEA: Biologists use experiments to test hypotheses. Circle the dependent variable in each sentence. Draw a box around the independent variable. 14. A scientist is testing the effects of medication on the blood pressure of patients. 15. A scientist wants to find out how cellular respiration is affected by temperature. 16. A scientist is measuring the effect of precipitation on seed germination. Draw lines to match each type of investigation with an example. 17. Observational study Adding a solid to a liquid to find out if the solid will dissolve 18. Experiment Watching the migration patterns of white storks MAIN IDEA: A theory explains a wide range of observations. Choose whether each statement is true or false. 19. true / false A theory is a scientific idea that has been proven to be true. 20. true / false Theories can change over time as new evidence is discovered. Vocabulary Check Draw lines to connect the phrases that mean the same thing. 21. independent variable conclusion 22. dependent variable condition that is changed by a scientist 23. theory data 24. constant condition that does not change Holt McDougal Biology 6 Biology in the 21st Century Section 3: Scientific Thinking and Processes
Section 4: Biologists Tools and Technology KEY CONCEPT Technology continually changes the way biologists work. VOCABULARY microscope gene molecular genetics genomics MAIN IDEA: Imaging technologies provide new views of life. Use the correct term from the box below to fill in the description with the correct type of technology. light microscope (LM) magnetic resonance imaging (MRI) transmission electron microscope (TEM) scanning electron microscope (SEM) 1. uses light and lenses to magnify images, can be used with living specimens, and can clearly magnify specimens up to about 1500 times. 2. uses electrons and computers to magnify specimens and produce three-dimensional images, cannot be used to observe living specimens, creates images that are computer colorized, and can clearly magnify specimens more than 100,000 times. 3. uses electrons and computers to magnify specimens and produce two-dimensional images, cannot be used to observe living specimens, creates images that are computer colorized, and can clearly magnify specimens more than 100,000 times. 4. uses strong magnetic fields to show a cross section of a body part and can show both soft tissues and dense tissues. Cross sections can be combined by computer to give a complete image of the whole area. Holt McDougal Biology 7 Biology in the 21st Century Section 4: Biologists Tools and Technology
continued MAIN IDEA: Complex systems are modeled on computers. Choose the best answer to the question. 5. Which of the following studies do you think would be most suitable for a computer model? a. A study of how fast an epidemic disease could spread in a city. b. A study of what life forms can be found in a local pond. c. A study of how animals react to confinement in a zoo or wildlife park. d. A study of how a new type of plastic could be used and what properties it has. 6. What kinds of systems are scientists most likely to model using computers? a. biological systems b. physical systems c. simple systems d. complex systems MAIN IDEA: The tools of molecular genetics give rise to new biological studies. Choose whether the statement is true or false. 7. true / false Scientists now have the ability to manipulate DNA. 8. true / false It is not possible to map the entire human genome. 9. true / false A gene is a type of computer model used to study diseases. Vocabulary Check Draw lines to match each word or phrase with its correct meaning. 10. gene the study of genomes 11. molecular genetics a tool for enlarging images 12. genomics the study and manipulation of DNA 13. microscope a segment of DNA that stores genetic information Holt McDougal Biology 8 Biology in the 21st Century Section 4: Biologists Tools and Technology
Section 5: Biology and Your Future KEY CONCEPT Understanding biology can help you make informed decisions. VOCABULARY biotechnology transgenic MAIN IDEA: Your health and the health of the environment depend on your knowledge of biology. Fill in the mind map with three ways that biology affects your health and the world around you. Your health 1. 2. 3. Importance of biology The world around you 4. 5. 6. MAIN IDEA: Biotechnology offers great promise but also raises many issues. Use the chart below to list the benefits of biotechnology, as well as the risks and ethical concerns about biotechnology. Benefits Risks and Ethical Concerns 7. 8. Holt McDougal Biology 9 Biology in the 21st Century Section 5: Biology and Your Future
continued MAIN IDEA: Biology presents many unanswered questions. What questions do you have about biology or scientific research? List three topics in biology that you want to learn more about. 9. 10. 11. Vocabulary Check Choose the answer that best completes each sentence. 12. Biotechnology is technology based on a. geological processes. b. astronomical events. c. living things and biological processes. d. computer modeling. 13. A transgenic organism is one that a. already exists in nature. b. has been developed through genetic manipulation. c. developed when two species reproduced together in nature. d. exists only as a computer model, but not in real life. Holt McDougal Biology 10 Biology in the 21st Century Section 5: Biology and Your Future