Chapter 1 Introduction to Biology.docx

**Disclaimer:** **Please note that the content provided here is intended solely to help you study and prepare for exams, though not every test question will come directly from this material. This outline and the information presented should offer a solid foundation for a successful outcome. However...

**Disclaimer:** **Please note that the content provided here is intended solely to help you study and prepare for exams, though not every test question will come directly from this material. This outline and the information presented should offer a solid foundation for a successful outcome. However, there may be some discrepancies between what is shown on the slides and what appears here, so it\'s important to cross-reference both for clarity. I recommend printing this outline or the study guide available on Blackboard for taking notes during the lecture or as a reference while studying.** **Chapter 1: Themes and Concepts of Biology** **Biology Studies Life** - Biologists aim to answer these questions: - What are the shared properties that make something "alive"? - How do living things function? - How do we create levels of organization in its structure? - How did this diversity arise and continue? - BUT what makes something alive? **Properties of Life** - **Order** - **Sensitivity or response to environment** - **Reproduction** - **Adaptation** - **Growth and Development** - **Regulation/Homeostasis** - **Energy Processing** - **Evolution** **Order** - Organisms are: - Highly organized - Have a coordinated structure - All life consists of one or more cells **Sensitivity to Environment** - **Plants**: - Bending towards light - Climbing - Responding to touch - **Bacteria**: - Chemotaxis - Phototaxis - Movement can be a positive (towards stimuli) or negative (away from stimuli) response **Reproduction** - Single-celled and multicellular organisms replicate their DNA to create "offspring" that belong to the same species. **Adaptation** - Living organisms exhibit a "fit" to their environment, also known as adaptation. - Evolution by natural selection. - Example: Heat-resistant Archaea bacteria. **Growth and Development** - Organisms grow and develop according to specific instructions in their genes. - They will exhibit many of the same characteristics as their parents. **Regulation/Homeostasis** - **Homeostasis**: Maintains internal conditions within a narrow range almost constantly, despite environmental changes. - Requires multiple regulatory mechanisms. - Example: Humans regulating body temperature, freshwater fish balancing salt levels, and plants regulating water loss. **Energy Processing** - All organisms use a source of energy: - Sun → Chemical Energy - Food → Chemical Energy **Evolution** - Mutations/genetic changes allow organisms to adapt to a changing environment, creating diversity. - Example: Peppered Moth. **Review -- 8 Characteristics of Living Organisms** - Order - Sensitivity to Environment - Reproduction - Adaptation - Growth and Development - Regulation/Homeostasis - Energy Processing - Evolution **Levels of Organization** - **Atom**: Smallest fundamental unit. - **Molecule**: Two or more atoms bonded by chemical bonds. - **Macromolecule**: Large molecules, e.g., DNA. - **Organelle**: Specialized structure with a specialized function. - **Cell**: Smallest fundamental unit of structure and function -- the building block of life. **Levels of Organization: Prokaryotic vs. Eukaryotic Cells** - **Prokaryotic Cells**: - Single-celled organisms. - Lack organelles surrounded by a membrane. - Do NOT have a nucleus surrounded by a nuclear membrane. - **Eukaryotic Cells**: - Can be single-celled or multicellular. - Have membrane-bound organelles. - Have a nucleus with a nuclear membrane. **Levels of Organization** - **Cell**: Smallest unit of life. - **Tissues**: Similar cells carry out similar functions. - **Organs**: Collections of tissues carrying out similar functions. - **Organ System**: A higher-order system of organs that work together for related functions. - **Organism**: An individual living entity. **Higher Levels of Organization** - **Population**: All individuals within a species within an area. - Can have different populations within an area. - **Community**: The sum of all populations in an area. - **Ecosystem**: All living and nonliving (abiotic) things within an area. - **Biosphere**: Collection of ecosystems. Includes land, water, and portions of the atmosphere. **Taxonomic Hierarchy** **Carl Linnaeus -- 18th Century**: - **Domain** - **Kingdom** - **Phylum** - **Class** - **Order** - **Family** - **Genus** - **Species** **Mnemonic**: \"Dear King Philip Came Over For Good Soup.\" **Species** - **Panthera leo** (Lion) -- The individual organism that can interbreed with others of its kind and produce fertile offspring. **Genus** - **Panthera** -- The genus that includes large cats like lions, tigers, leopards, and jaguars. Species that are similar and share a common ancestor. **Family** - **Felidae** -- The cat family, which includes both big cats (like lions) and small cats (like domestic cats). **Order** - **Carnivora** -- The order of mammals that primarily eat meat, including cats, dogs, bears, and weasels. **Class** - **Mammalia** -- The class of warm-blooded animals with fur or hair and which produce milk to feed their young. **Phylum** - **Chordata** -- The phylum that includes animals with a notochord (a flexible rod in the back), such as vertebrates. **Kingdom** - **Animalia** -- The kingdom that includes all animals, characterized by being multicellular, eukaryotic organisms that can move at some stage in their life. **Domain** - **Eukarya** -- The domain that includes all organisms with eukaryotic cells, which have a true nucleus and other membrane-bound organelles. **Binomial Naming System** - Developed by Carl Linnaeus. - Both names are italicized: - The genus name (capitalized). - The species name (lowercase). - For humans, *Homo sapiens*, Homo is the genus and sapiens is the species. - For the red maple tree, *Acer rubrum*, Acer is the genus and rubrum is the species. **The Diversity of Life -- Phylogenetic Tree** - Summarizes the evolution of life based on similarities/differences in genetics or physical traits. - **Nodes**: When ancestors diverged. - **Length of branch**: Proportional to time elapsed. **Carl Woese (1970s)**:\ Developed a tree based on genetic similarities with 3 Domains -- Bacteria, Archaea, and Eukarya. **Branches of Biological Study** Due to the diversity of life, the fields of biology are also diverse: **Scientific Ethics** - Like all fields, there are ethical considerations. - Bioethics gained significant attention and development after the 1932 Tuskegee Syphilis Study. - Balancing the benefits and potential harm is a central challenge in scientific ethics. **Review Objectives** - **Identify and describe the properties of life**:\ Order, Sensitivity, Reproduction, Adaptation, Growth/Development, Homeostasis, Energy Processing, and Evolution. - **Describe the levels of organization**:\ Atom → Molecule → Macromolecule → Organelle → Cell → Tissue → Organ → Organ Systems → Organism → Population → Community → Ecosystem → Biosphere. - **List examples of different subdisciplines of biology**:\ Microbiology, Neurobiology, Paleontology, and Biochemistry. - **List the taxonomic categories large to small**:\ Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species. - **Describe the role ethics plays**:\ Balance harm/benefits and prevent undue harm to humans, animals, and the environment. **The Process of Science - Objectives** - **Identify the shared characteristics of natural science**. - **Understand the process of scientific inquiry**. - **Compare inductive/deductive reasoning**. - **Describe the goals of basic/applied science**. - **Be able to create a valid hypothesis**. - **Know the difference between a hypothesis, theory, and law**. - **Know the difference between a variable and control in an experiment**. **Nature of Science/Scientific Method** - **Scientific Method**: A specific way of learning/knowing about the world. - **Hypothesis**: An \'educated guess\' that is testable and falsifiable. - **Scientific Theory**: A tested and confirmed explanation -- explains \"why\" or \"how\" something happens. - **Scientific Laws**: Often mathematical formulas that describe how things act under certain conditions -- describes \"what\" happens. **Natural Sciences** - Natural Science is how fields of science are related to the physical world. - There is no universal agreement on the exact definition of natural sciences. - Can be broken into life sciences and physical sciences. **Scientific Inquiry** - **Inductive Reasoning**: Generalizing from specific observations. Starts with specific instances and moves toward a general conclusion. Data can be qualitative (descriptive) or quantitative (numbers). - **Deductive Reasoning**: Applying general principles or logic to specific cases. Moves in the opposite direction. Starts with a general premise and leads to a specific conclusion. **Descriptive Science vs Hypothesis-Based Science** - **Descriptive Science**: Aims to observe, explore, and discover. - **Hypothesis-Based Science**: Begins with a specific question and a potential answer. Boundaries are blurred. Observations lead to questions, and questions lead to a hypothesis. **Hypothesis Testing** - **Hypothesis**: Start with an observation, have a question, ask "why?". Must be falsifiable. - Example Hypothesis: If bread dough is placed in a warmer environment, then it will rise faster. - **Prediction**: If I place one batch of bread dough in a warm oven and another at room temperature, the dough in the warm oven will double in size faster. - **Variable**: Any part of the experiment that can change. - Example: The temperature of the environment where the dough is placed (warm oven vs. room temperature). - **Control**: The part of the experiment that does not change. - Example: The dough at room temperature acts as the control, in a typical environment, so you can compare its rising time to the dough in the warm oven. **Basic and Applied Science** - **Basic Science**: Expands knowledge for the sake of understanding fundamental principles. - **Applied Science**: Uses scientific knowledge to solve real-world problems and develop new technologies. - Example: The **Human Genome Project**, which combined fundamental research with practical applications to advance medicine and genetics. **Peer-Reviewed Articles** - Facilitate communication by allowing researchers to share and discuss findings. - Advance knowledge by contributing to the progress of scientific understanding. - Reviewed by experts for reliability and accuracy. - Generally considered more reliable and useful than non-peer-reviewed sources. **Review Objectives** - Identify the shared characteristics of natural science. - Fields: Related to the physical world and its phenomena and processes. - Understand the process of scientific inquiry. - **Process**: Observation → Hypothesis → Prediction → Experiment → Analyze. - Compare inductive and deductive reasoning. - **Inductive Reasoning**: Uses specific observations to develop a general conclusion. - **Deductive Reasoning**: Uses a general principle or law to predict specific results. - Describe the goals of basic/applied science. - **Basic Science**: Aims to expand knowledge without concern for immediate practical applications. - **Applied Science**: Uses scientific knowledge to address and solve real-world problems. - Be able to create a valid hypothesis. - **Hypothesis Definition**: A suggested explanation for an event or phenomenon. - **Example**: \"If the temperature of water is increased, then the rate at which sugar dissolves in it will also increase.\" - Know the difference between a hypothesis, theory, and law. - **Hypothesis**: A testable prediction about how variables are related. - **Theory**: A well-substantiated explanation of why something happens, supported by extensive evidence and research. - **Law**: A description of what consistently happens under specific conditions, often expressed as a mathematical relationship. - Know the difference between a variable and a control in an experiment. - **Variable**: Any factor that can be changed or measured in an experiment. It includes both independent variables (manipulated) and dependent variables (observed). - **Control**: The constant factor that remains unchanged throughout the experiment, used as a baseline to compare the effects of the variable.