Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Biology and You Table of Contents Section 1 Themes of Biology Section.

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Biology and You Table of Contents Section 1 Themes of Biology Section 2 Biology in Your World Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 1 Themes of Biology Objectives Relate the seven properties of life to a living organism. Describe seven themes that can help you organize what you learn about biology. Identify the tiny structures that make up all living organisms. Differentiate between reproduction and heredity and between metabolism and homeostasis. Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Characteristics of Living Organisms Biology is the study of life. All living organisms share certain general properties that separate them from nonliving things. Properties of Life »Cellular organization »Reproduction »Metabolism »Homeostasis »Heredity »Responsiveness »Growth and development Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Characteristics of Living Organisms, continued Cellular organization - every living thing is composed of one or more cells Reproduction - all living things are able to reproduce Metabolism - all obtain and use energy to run the processes of life Homeostasis - living organisms maintain a consistent internal environment Heredity - living things pass traits to offspring Responsiveness - all living things respond and adjust to the environment Growth and development - all living things grow and develop Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology As you study biology you will repeatedly encounter the following seven themes. 1.Cellular Structure and Function 2.Reproduction 3.Metabolism 4.Homeostasis 5.Heredity 6.Evolution 7.Interdependence Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 1. Cellular Structure and Function Cells are highly organized, tiny structures with thin coverings called membranes. All living things are made of one or more cells. A cell is the smallest unit capable of all life functions. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 2. Reproduction Reproduction is the process by which organisms make more of their own kind from one generation to the next. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 3. Metabolism Metabolism is the sum of all the chemical reactions carried out in an organism. Almost all energy used by living organisms is originally captured from sunlight. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 4. Homeostasis Homeostasis is the maintenance of a stable internal conditions in spite of changes in the external environment. An organism unable to balance its internal conditions with its environmental conditions could become ill and die. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 5. Heredity Heredity is the passing of traits from parent to offspring. The basic unit of heredity is called a gene. Genes are coded in a molecule called deoxyribonucleic acid (DNA). Genes determine an organism’s traits. A change in the DNA of a gene is called a mutation. Most mutations are harmful, but some mutations can help an organism survive. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 6. Evolution Evolution is defined as change in the inherited characteristics of species over generations. A species is a group of genetically similar organisms that can produce fertile offspring. Natural selection is the process in which organisms with favorable traits are more likely to survive and reproduce. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Unifying Themes of Biology, continued 7. Interdependence The organisms in a biological community live and interact with other organisms. Ecology is the branch of biology that studies the interactions of organisms with one another and with the nonliving part of their environment. Organisms are dependent on each other and on their environment. Section 1 Themes of Biology Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Biology in Your World Objectives Evaluate the impact of scientific research on the environment. Evaluate the impact of scientific research on society with respect to increasing food supplies. Explain the primary task of the Human Genome Project. Describe the contributions of scientists in fighting AIDS and cancer. Define the term gene therapy. Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Solving Real-World Problems Biologists are working to solve today’s problems, such as: Preserving our environment Improving the food supply Understanding the human genome Fighting disease Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Solving Real-World Problems, continued Preserving our environment Conservation biologists are exploring ways to achieve a balance between people’s growing need for land and the need to preserve the environment. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Solving Real-World Problems, continued Improving the food supply Genetic engineering of crop plants has made some plants resistant to herbicides, or poisonous to insect pests, or more nutritious. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Solving Real-World Problems, continued Understanding the human genome A genome is the complete genetic material contained in an individual. Government-funded and private research teams from several countries completed sequencing of the human genome. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fighting Disease AIDS is a fatal disease caused by HIV (human immunodeficiency virus), a virus that attacks and destroys the human immune system. New vaccines are being tested that attack two or more parts of the HIV virus at the same time. So that while one part may mutate, it us unlikely that both parts will mutate in the same virus particle. There is finally hope of a successful vaccine to control the outbreak of AIDS. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fighting Disease, continued Cancer is a growth defect in cells, a breakdown of the mechanism that controls cell division. Great progress is being made in curing many cancers. Several forms of cancer result from having too many copies of a certain protein. Anticancer drugs that stick to these extra cell proteins appear to offer great promise. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fighting Disease, continued Emerging diseases Biologists are fighting new diseases not known in the past. Some of these diseases include West Nile virus and mad cow disease. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Fighting Disease, continued Gene Therapy is the replacement of a defective gene with a normal one. Researchers believe it is possible to use a virus to transfer a normal copy of a gene into a cell. Researchers hoped to cure cystic fibrosis, a hereditary disease in which a thick sticky mucus clogs the body’s breathing passages. Early attempts failed because the virus used caused health problems. New attempts using a different virus are more promising. Section 2 Biology in Your World Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 3 Scientific Processes Objectives Describe the stages common to scientific investigations. Distinguish between forming a hypothesis and making a prediction. Differentiate a control group from an experimental group and an independent variable from a dependent variable. Define the word theory as used by a scientist. Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Observation: The Basis of Scientific Research Observation is the act of noting or perceiving objects or events using the senses. All scientists have a certain way of investigating the world. Scientific investigations begin with observations. Observations cause scientists to ask questions about their observations. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations Scientific investigations tend to have common stages. These stages are called the Scientific Method. There is more than one way to conduct an investigation. Scientific Methods or Scientific Processes are more accurate terms for the stages of scientific investigation. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Scientific Processes include the following stages. Collecting observations Asking questions Forming hypotheses and making predictions Confirming predictions (with experiments when needed) Drawing conclusions Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Hypothesis—an explanation that might be true, a statement that can be tested by additional observations or experimentation Prediction—the expected outcome of a test, assuming the hypothesis is correct. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Experiment—a planned procedure to test a hypothesis. Control group—a group in an experiment that receives no experimental treatment. The control group is necessary for comparing the results of the experiment. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Independent variable—the factor that is changed in an experiment. Dependent variable—the variable that is measured in an experiment, the outcome of the dependent variable depends on what is done to the independent variable. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Drawing Conclusions Once data are collected and analyzed, a conclusion is made as to whether the data support the hypothesis. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Stages of Scientific Investigations, continued Viewing Conclusions in Context There is often more than one possible reason for a result. All of the factors that may affect an outcome must be considered. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Scientific Explanations Constructing a Theory Theory a set of related hypotheses that have been tested and confirmed many times by many scientists. A theory unites and explains a broad range of observations. The word theory is used by the general public to mean a guess, or lack of certainty. In science, a theory is a well-supported scientific explanation that makes useful predictions. Section 3 Scientific Processes Chapter 1

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Scientific Explanations, continued Constructing a Theory Scientists report their results. Scientific reports are reviewed by other scientists. Scientific reports allow other scientists to use the information obtained in an experiment. Scientific reports also allow other scientists to repeat and test experiments. Section 3 Scientific Processes Chapter 1