Chapter 1:IntroductionThemes in the Study of Life Wilkie South Fort Myers High School 2015-2016
Properties of Living Things (figure 1.3) All living things must meet seven criteria to be considered a living thing, what are they? 1. Order-Structural organization to perform specific functions. 2. Evolutionary Adaptations-Increasing survivability of a species by successful breeding due to inherited characteristics. 3. Response to stimulus-ability to respond to environmental changes in order to survive. 4. Regulation-Ability to maintain internal systems despite changes to the external environment. 5. Energy Processing-The necessity and ability to use energy to carry our life functions. 6. Growth and Development-The use of inherited molecular information to promote growth and development of organisms. 7. Reproduction-Ability to pass on inherited molecular information to future generations ensuring survival of the species.
Emergent Properties What is an emergent property? Emergent properties are those structures or processes that result from an accumulation of smaller parts. An example of this is the way that water behaves in the environment. Water needs to reach the top of a tree in order to support photosynthesis. In order to defy gravity and travel up the tree, water relies on a process known as cohesion (where water molecules stick to each other) and adhesion (where water sticks to other substances) Water s cohesive ability is the result of a hydrogen bond that forms between the positive and negative end of two or more water molecules. Water has a positive and negative end because it is a polar molecule with unequal distribution of electrons. Water is polar because oxygen is a highly electronegative atom while hydrogen has a low electronegativity. For another example view the online lecture
Life at different scales (figure 1.4) What are the different scales in which we study biology? 1. Biosphere: all environments on Earth 2. Ecosystem: all living and nonliving things in a particular area 3. Community: all organisms in an ecosystem 4. Population: all individuals of a species in a particular area 5. Organism: an individual living thing. 6. Organ and organ systems: specialized body parts made up of tissues 7. Tissue: a group of similar cells 8. Cell: life s fundamental unit of structure and function 9. Organelle: a structural component of a cell 10. Molecule: a chemical structure consisting of atoms 11. Atom/Element: the simplest form of matter that can maintain the characteristics of a substance.
What are the four big ideas of AP biology? Each of the hyperlinks to the right will link you to the curriculum guide for AP Biology (if they don t work that document has been loaded up to the google classroom page). Search and find the pages that describe each big idea. Try your best to summarize in a few sentences the main idea behind each big idea and provide an example of what can be studied in that big idea. Big Idea #1-The process of evolution drives the diversity of life. Big Idea #2-Biological systems utilize free energy and molecular building blocks to grow, reproduce and to maintain dynamic homeostasis Big Idea #3-Living systems store, retrieve, transmit and respond to information essential to life processes Big Idea 4-Biological systems interact, and these systems and their interactions possess complex properties
How are organisms classified and grouped? (figure 1.14) Organisms can be grouped in a variety of ways, we will explore most of them this year. Taxonomically (based on the Linnaean system) organisms are placed into increasingly more specific groups based on their anatomical (physical) characteristics. The domain eukarya contains all living things that are made up of eukaryote cells, therefore that level is the most diverse. Kingdom focuses only on the organisms that are considered animals (multicellular, heterotrophic) Chordata refines all animals to only those with a notochord (structure associated with the backbone) Increasing refinement will eventually end in the Genus and species and should identify a single type of organism.
Taxonomy and Evolution, what is the connection? Carolus Linnaeus was the first person to use physical characteristics to organize organisms into specific groups. This comparison lay the groundwork for connections that Charles Darwin would later make that has lead to what is widely considered to be one of the most important insights in human history. What two main points does Darwin articulate in his revolutionary work The Origin of Species? Darwin s first point, based on years of observation, is that existing species today arose form a succession of ancestors. His second point was that a mechanism must have been in place to cause the alteration of structures in organisms that would give rise to the diversity that exists today. He called this mechanism descent with modification, which we commonly refer to as natural selection. Natural selection results from three main observations that are summarized as follows: Organism of one species in a population are not the same, they have variation Organisms will produce more offspring than can possibly be supported by the environment. Organisms best suited for survival in their particular environment will be more successful and leave behind more offspring
How do we illustrate the evolutionary relationship between species? (figure 1.22) Often referred to as Darwin s toolbox, the finches of the Galapagos Islands have long been associated with the theory of Evolution. Later this year you will read part of The Beak of the Finch, which documents evidence of evolution with detailed, meticulous observation. An evolutionary tree like the one to the right illustrates how species relate to one another. At the base of the tree is the common ancestor. In the case of the Galapagos Finches, this species likely arrived from South America and then underwent adaptive radiation. Each terminal branch represents an individual species. A species is defined by one that can only breed successfully with its own kind. As you can see some species have distinctly different beak shapes. The branches on the tree represent distinct differences that separate groups of finches from each other and eventually individual species from each other. For instance, the finches are broken into there distinct groups (ground finches, tree finches, and warbler finches). The adaptations these finches have separate them based on their feeding behavior and ecological niche.
How do we arrive at conclusions related to biological principles? No doubt you are aware of the scientific method. This structured approach to scientific inquiry has been around for centuries. At the heart of the scientific method is observation that leads to data. Problem/Question Hypothesis Variables (independent, dependent, constant, control group) Quantitative data is data that is based on measurement and is often presented through charts and graphs. Procedure Observation (Quantitative/Qualitative) Data Analysis/Presentation Conclusion Qualitative data is data that is often associated with sensory observations (sight, smell, etc.) this data is usually presented through illustration. Peer Review
How do we arrive at conclusions related to biological principles? No doubt you are aware of the scientific method. This structured approach to scientific inquiry has been around for centuries. Problem/Question Hypothesis Variables (independent, dependent, constant, control group) Procedure Observation (Quantitative/Qualitative) Data Analysis/Presentation Conclusion Peer Review A hypothesis is tentative answer to a well thought out experimental problem or question. A well articulated hypothesis needs to be testable (usually through the scientific method) and often allows us to make further predictions that lead to additional test or observations. What you may be less than familiar with is a null hypothesis. If a hypothesis for the problem associated with figure 1.24 to the right is that changing the batteries on the flashlight will increase the light produced, then the null hypothesis is changing the batteries will have no affect on the amount of light produced. Essentially a null hypothesis is the opposite of your hypothesis. As you will see later in the year a Null hypothesis is important in statistical analysis of quantitative data.
How do we arrive at conclusions related to biological principles? No doubt you are aware of the scientific method. This structured approach to scientific inquiry has been around for centuries. Problem/Question Hypothesis Variables (independent, dependent, constant, control group) Procedure Observation (Quantitative/Qualitative) Data Analysis/Presentation Conclusion Peer Review A good experimental design will clearly describe the variables being tested: An independent variable is that in which you are changing on purpose. In most instances experiments should limit the independent variable to one thing being changed at a time. A dependent variable is what is being measured or observed and may be influenced by the independent variable. It is important when designing and experiment to determine what you will measure, how you will measure it and what units you will be using in your analysis. The constant variables and control group are often confused. A constant variable are those that if not kept the same through out the experiment may influence the outcome and limit your ability to understand the affect that your independent variable is having. The control group is not a variable but is actually an experiment run in tandem with your experimental group. The control group has all conditions the same as the experimental group, but the independent variable is replaced with the conditions most similar to the natural environment in which the organism being investigated comes from.
Using the Scientific Method in AP Biology Through out the year you will be asked to utilize the scientific method to increase your understanding of major biological processes. Your responsibilities will include: Conducting guided labs, collecting quantitative data, analyzing that data and writing detailed conclusions. Designing your own scientific investigations to extend your understanding beyond the guided labs. Answer free and short response questions that focus on experimental design and data analysis: In the next few slides I have posted a few of the many free response questions related to experimental design and data analysis so you can familiarize yourself with these types of questions. At the end of most powerpoints I will be including released free response questions. These are for your benefit as I will use them periodically during our units of study as "pop" writing quizzes to help you improve your writing for the AP exam...so don't ignore them!