Biology I – S409 Chapter 1 Notes The Study of Life 1 Name: Hour: Date:

Section 1: Intro to Biology The Science of Life BIO = life BIO = life LOGOS = study LOGOS = study Biology is the study of all living things (organisms, or the science of life) -When people study living things or pose questions about how living things interact with the environment, they are learning about biology. A person who studies living things is referred to as a biologist. Biology is the study of all living things (organisms, or the science of life) -When people study living things or pose questions about how living things interact with the environment, they are learning about biology. A person who studies living things is referred to as a biologist. 2 T: 2

What do biologists “do”? Study the diversity of life – –Jane Goodall learning about chimps, now we can protect them… Research diseases – –From Goodall’s work, Mary King studied chimp DNA to better understand breast cancer Develop technologies – –Bionic “parts” or artificial limbs, medicine, treatments Improve agriculture – –Genetic engineering to allow plants to grow in nutrient poor soil or withstand disease; increase production Preserve the environment – –Prevent extinction of animals and plants (captivity programs) 3 T: 2 Scientists are: Observant, Skeptical, Curious and Open-minded!

Characteristics of Life 1. Made of CELLS: unicellular / multi-cellular 2. Are ORGANIZED (cells make up tissues…) 3. GROW and DEVELOP 4. REPRODUCE: ”Like produces like” -Sexual vs. Asexual Reproduction 5. RESPOND to stimuli: either internal or external (migrate) 6. Require ENERGY 7. Maintain HOMEOSTASIS: a stable internal environment 8. ADAPTATIONS/EVOLVE over time -occurs in populations, NOT individual organisms Characteristics of Life 4 T: 2, 7

Levels of Organization in Living Things (#2 on previous slide) Molecules↓Cells↓Tissues↓Organs↓Systems↓Organisms↓Populations↓Communities↓Ecosystems↓Biosphere Organization of an organism Ecological Organization 5 T: 8

Concept Check 1. 1.If something reproduces asexually (for example: a starfish growing a new arm after being broken off by a predator or a broken vine landing in soil and starting to grow into a new plant) is it still considered to be a living thing? – –Yes or No – –Yes! Though not all living things reproduce asexually, it is still a form of reproduction 2. 2.Is the ability to breathe a characteristic of life? – –Yes or No – –NO! Though some living things do breathe (animals) there are other living things that do not (bacteria, plants, fungus) 6

Think about this… Do mice come from straw? Do frogs come from mud? Do maggots come from meat? If you answered no to any of the above questions in the 1600's, people would think you were crazy. These things were all considered to be true facts until the year Spontaneous Generation: AKA “ a biogenesis” – –Living organisms are generated by decaying organic substances – –EX: mice spontaneously appear in stored grain or maggots spontaneously appear in meat 10 7 T: 2

Redi’s Controlled Experiment OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat. HYPOTHESIS: If flies land on meat, then maggots will be produced. PROCEDURE Controlled variables: jars, type of meat, location, temperature, time Manipulated Variable: gauze covering that keeps flies away from meat Uncovered jarsCovered jars Several days pass Maggots appearNo maggots appear Responding Variable: whether maggots appear CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. Section 1- 2 Go to Section: 8 T: 2 *Biogenesis: living things only come from other living things as a result of reproduction

Section 2: The Nature of Science What is science?  Science: the body of knowledge based on the study of nature (biology, chemistry, physics, Earth science)  In science class we will: Rely on evidence Expand scientific knowledge Challenge accepted theories Question results Test Claims Use peer review Use the metric system: units with divisions that are powers of ten (International System of Units = SI)  (meter = length, gram = mass, liter = volume, second = time) 9 T: 16

How curious are you??? You throw away the outside and cook the inside. Then you eat the outside and throw away the inside. What did you eat? –ANSWER: an ear of corn What goes around the world but stays in a corner? –ANSWER: a stamp Give me food, and I will live; give me water, and I will die. What am I? –ANSWER: a fire I'm where yesterday follows today, and tomorrow's in the middle. What am I? –ANSWER: a dictionary I have hands that wave at you, though I never say goodbye. It's cool for you to be with me, especially when I say, "HI.“ What am I? –ANSWER: a fan 10

Science is the body of knowledge based on the study of nature; which leads to the development of explanations. Scientific explanations combine consist evidence gathered from many observations and experiments. THEORY – –Explanation that has been tested and – –not yet disproved (several experiments) – –EX: Theory of Evolution, Cell Theory LAW – –Statement about nature that is ALWAYS TRUE – –EX: Law of Biogenesis Theory vs. Law 11 T: 5

Concept Check 1. 1.In science, is it acceptable to use measurements such as inch or foot? – –Yes or No – –NO! In science it is considered proper to use the SI measurement system with the corresponding prefix. Length: meter Volume: liter Mass: gram 2. 2.If you have enough experimental data to support a hypothesis, is that a law or a theory? – –Theory; something that has not yet been disproved; has extensive evidence and allows for making accurate predictions 12

Observations lead to questions… how are they answered? Science follows a process (AKA scientific method): 1. 1.Ask a Question (Define the Problem) – –Observations: collected with your senses – –Inferences: made with your mind, used to explain observations – –Collect Data/Background information when necessary Form a VALID hypothesis – –Must make a prediction; must be testable – –Must be stated in the “If … then… because…” format Section 3: Methods of Science 13 T: 1, 4, 14

3. 3.Collect the Data Controlled Experiments have experimental and control groups – –Control groups: used for comparison – –Experimental groups: the group exposed to the factor being tested The “independent” variable; the factor that changes; the thing that is being tested; only use 1 at a time (everything else in the experiment should be kept constant) The “dependent” variable(s) must be collected as data Quantitative Data: There are 3 mL of fluid; numeric Qualitative Data: The fluid is orange; word description Section 3: Methods of Science – Cont. 14 T: 3, 4, 6

4. 4.Analyze Data – –Graphs (bar or line), Tables, and Charts (pie) – –Bar Graph: used to compare different groups or track things over time – –Line Graph: used to track changes over time (connect the dots) – –X-Y Scatter Plot: line of best fit (average) – –Table: used to display data in an organized way – –Chart (Pie): used to compare parts of a whole (%) 5. 5.Report or Form Conclusions Accept or reject your hypothesis based on the data collected Section 3: Methods of Science – Cont. NAMETIME Frank 33 sec Jessica 27 sec 15 T: 3, 4, 13

Tools of a Biologist: The Microscope Compound Light Microscope – –uses light reflected by two or more lenses – –1 eyepiece, 1 light (light passes through) – –Used to view small specimens (alive or preserved) Stereoscope (AKA Dissecting Microscope) – –2 eyepieces, 3 light combos (3-D objects) – –Used to view larger specimens (alive or preserved) Electron Microscope – –Uses electrons reflected by magnets – –Can only be used with non-living specimens – –Two types (SEM & TEM) * We will use the CLM & Stereoscope in Bio I 16 T: 9

2 Types of Electron Microscopes A. Scanning Electron Microscope (SEM) electrons bounce off specimen produces 3-D image lower magnification than TEM B. Transmission Electron Microscope (TEM) electrons travel through the specimen higher magnification than SEM no 3-D image specimen must be frozen, embedded in plastic, and sliced into a thin piece Structure and Function of the Electron Microscope 17 T: 9

Microscope Vocabulary  Total Magnification Calculated by multiplying ocular magnification by objective magnification  Field of view What you see when looking in the eyepiece Gets smaller when you increase magnification  Working Distance Distance between objectives and stage Gets smaller when you use the high power objectives  Depth-of-field Occurs when you are looking closely at the layers of a specimen, you can actually see different layers at the same time! 18 T: 10, 12, 15

Stereoscope vs. Compound Light Microscope Eyepieces (2 vs. 1): 2 eyepieces allow for a 3-D image Lights (2 vs. 1): 2 lights allow you to see solid objects Size of Object: Larger working distances allows you to see bigger things 19

Concept Check 1.What type of microscope will we use in our classroom this year? Compound Light Microscope, Stereoscope, Electron Microscope Both the Compound Light Microscope and the Stereoscope 2.Which type of graph, table or chart is used to track data over time? Bar, Line, X-Y, table, pie A line graph is most commonly used to track data over time; a bar graph may also be used. It is important to pay attention to the type of data you have collected in order to best represent your findings! 20