Chapter 1 What is Biology? The study of life What kind of things would a Biologist study? Characteristics of known and new living things Interactions between living things Interactions between living things and the environment Problems living things face and possible solutions

Organisms possess all characteristics of life Organisms possess all characteristics of life. Which of these is not alive? http://en.wikipedia.org/wiki/Bacteria

5 Characteristics of Living Things #1 Living things are Organized All living things are made of one or more cells the parts that make up the organism are arranged in an orderly structure Levels of Organization

Atoms Molecules Organelles Cells Tissues Organs System Organism Population Communities Ecosystems

Characteristics of Living Things: #2 Living things Reproduce organisms produce offspring (reproduction) for the survival of the species species: group of organisms that can interbreed and produce fertile offspring in the future

Characteristics of Living Things : #3 Living things Change during their lives Growth: increase in the amount of living material and the formation of new structures Start as single cells and become more complex Changes throughout life are known as development

Characteristics of Living Things : #4 Living things Respond to their surroundings Organisms are affected by their environment (such as air, water, weather, temperature, other organisms) Conditions in the environment can cause a reaction by the organism. Stimulus  Response Why respond? To Survive! Regulating internal conditions suitable for survival: homeostasis Water, temperature, nutrients

Characteristics of Living Things: #5 Living things Obtain and use Energy Energy – ability to do work You get energy from the foods you eat

Chapter 1: Introduction to Biology---Measurement, Graphing, and Scientific Method Types of Research Two main types Quantitative Uses controlled experiments Results are numerical data Descriptive Relies on observations of situations out of scientist’s control Results are descriptions of observations Often an important tool for wildlife studies

Quantitative Research Data are analyzed by comparing the numerical values Tables Graphs Measurements are made using the International System of Measurement (SI) Based upon the metric system Understandable to scientists around the world

Effects of Fertilizer on Plant Height Tables All tables must include the following Title Clearly labeled columns and rows Labeled units Data should show relationship between independent and dependent variable Effects of Fertilizer on Plant Height Amount of Plant Fertilizer (g) Independent Height of Plant (cm) Dependent 2 12 6 20 10 4

Graphs All graphs must include the following Title A label for each axis Labeled units Legend Data properly depicted * Independent on x-axis * Dependant on y-axis y-axis x-axis

Graphs What type of graph should I use? Line For continuous quantitative data Height of plant over time Stock market prices over time Line graph relationships Direct variation – one variable increases as the other increases (or decreases as the other decreases) Inverse variation – one variable decreases as the other increases

Graphs Bar Pie For non-continuous data (usually in categories) Number of people who watch each TV show surveyed Pie For data that are parts of a whole Percentage of those polled that chose each TV show

International System of Measurement (SI) Basic units of measurement Length – meter (m) Tool – ruler or meter stick Volume – liter (L) Tool – graduated cylinder Mass – gram (g) Tool – triple-beam balance Time – second (s) Tool - stopwatch Temperature – Kelvin (K) [We will most often use Celsius (°C)] Tool - thermometer

Units of Measurement Metric system – based on 10 kilo (k) – kilometers (km) 1000 meters hecto (h) – hectometers (hm) 100 meters deca (da) – decameters (dam) 10 meters Basic unit (m, L, g) – meter (m) 1 meter deci (d) – decimeter (dm) 0.1 meter centi (c) – centimeter (cm) 0.01 meter milli (m) – millimeter (mm) 0.001 meter

Converting one metric unit to another k h da Basic unit d c m (m, L, g) To convert from one unit to another, move the decimal same direction and number of places the units are from each other 12 kilometers is ?? centimeters centimeters are 5 places to the right 1,200,000 cm 134 decigrams is ?? hectograms hectograms are 3 places to the left 0.134 hg

Science and Society Ethics – moral principles and values held by humans What role do ethics play in scientific research and results? Can science answer all questions? Technology – application of scientific research to address society’s needs Can technology solve all problems?

Scientific Investigation vs Technological Design Scientific Investigation – process followed to determine the relationship between the independent and dependent variable described by the hypothesis Goal is to answer a question, perhaps advance the knowledge of science Did using this new fuel help lower pollution? Technological Design – process followed to design products or processes to meet specific needs Goal is to create a specific outcome, perhaps advance the standard of living in societies We have created a lower pollution emitting car

Scientific Investigation vs Technological Design Identifies a problem – asks a question Identifies a problem or need Researches related information Designs an investigation or experiment Designs a process or a product Conducts the investigation or experiment – repeated trials Implements the design or the process – repeated testing Analyzes the results Evaluates the conclusion – did the results refute or verify the hypothesis Evaluates the process or product – did it meet the criteria Communicates the findings Communicates the product or process

Methods of Biology The series of steps used by scientists to gather information and answer questions is called the Scientific Method. If you had a question or a problem to solve, what steps would you go through to resolve it?

7 Steps of the Scientific Method Number 1 - State the Problem Take note of something no one has seen before or has yet to explain

7 Steps of the Scientific Method Number 2 - Gather Information Observation - Gathering information using your senses Information gathered should be: Credible - trustworthy Accurate - correct – based on supported data Relevant - applicable, related to the topic of the investigation These sources could be Previous scientific investigations Science journals Textbooks Other credible sources, such as scientifically reliable internet sites.

Observation vs. Inference Inference – making a judgment based upon an observation and past experience Fact or Fiction?

7 Steps of the Scientific Method Number 3 - Form a Hypothesis Create a testable explanation for the situation that you observed

7 Steps of the Scientific Method Number 4 - Test the Hypothesis - Experiment Design an experiment An organized procedure for collecting information under controlled conditions The experiment will have two groups Control – all conditions are kept the same Experimental – conditions match that of the control except for the one factor being tested

7 Steps of the Scientific Method Testing… An important part in the experiment design is the sample size – the number of test subjects A large sample size increases the reliability of results A large sample size decreases the effect of errors on the outcome How could having a larger sample size help the following experiments? Tim tested the effect of fertilizer on two plants. The one with fertilizer grew taller than the one without it. Suzy developed a drug to lower cholesterol. She gave it to two patients who later died.

7 Steps of the Scientific Method Testing… The condition that is changed in the experiment is the independent variable – it will be the only thing that can affect the outcome The outcome observed is the dependent variable – it depends upon the changes made to the independent variable Note: Some experiments cannot be controlled so other observation methods have to be used Example: wildlife study

Independent vs. Dependent Variables Mark the dependent and independent variable in each situation Suzy wanted to test how changing her diet affected her weight. The track team members that ran extra laps at practice ran better times at the next meet. Jack planted half of his roses in the shade and the other half in the direct sunlight and measured the differences in plant height and bloom production.

7 Steps of the Scientific Method Number 5 - Record and Analyze Data Record Data Data – information obtained from experiments Observations Results Data should be precise and accurate Precision – the degree to which measurements made in the same way agree with each other If you and I measure it, do we get the same thing? Accuracy – the degree to which the value measured agrees with the true or accepted value Even if we both got the same thing, did we measure it correctly? Data must then be analyzed or interpreted Graphs Tables Charts

7 Steps of the Scientific Method Number 6 - State a Conclusion Did the data support the hypothesis? If yes… Verify results Can the experiment be repeated? Do other scientists support the findings? If no… Repeat the experiment Revise the experiment Develop a new hypothesis Always Report Results!

7 Steps of the Scientific Method Number 7 - Repeat No matter what happened! Fact – Observable phenomenon that can be confirmed by scientists many times Form a Theory – a hypothesis tested over a long period of time, supported by separate experiments

Fact vs. Theory Which is Fact…Which is Theory? Dinosaurs were cold blooded. The caterpillar is 3.5 cm long.

Using the Scientific Method You haven’t been catching as many fish as you used to at your best fishing spot Your friend tells you that you and your brother smell funny

Identifying Study Components A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few days, the wound begins to heal without ever showing signs of infection. The following steps outline the student's line of reasoning: I wonder why the dog's wound doesn't become infected. The dog's saliva must prevent the growth of infection-causing bacteria. I'll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes. Once the bacteria start growing, I'll add dog saliva to only one of the dishes and leave the other alone. I'll cover both dishes. Then I'll observe what happens each day for a week. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both dishes over the course of the week. However, the bacteria in the treated dish grew more slowly than the bacteria in the untreated dish. I think I'll try something else. I'll start with two identical culture dishes, as before, and use the same kind of bacteria in each dish, but this time I'll treat one dish with dog saliva before I add the bacteria. I'll observe what happens each day for a week. What was the student’s hypothesis? Which step described the experimental set up? Identify the control What is the independent variable? What is the dependent variable? What data did the student collect? What is a possible conclusion from this experiment? Is that conclusion a fact or an inference?

Identifying Study Components A student noticed that when a dog is cut, the dog periodically licks its wounds. Usually after a few days, the wound begins to heal without ever showing signs of infection. The following steps outline the student's line of reasoning: I wonder why the dog's wound doesn't become infected. The dog's saliva must prevent the growth of infection-causing bacteria. I'll obtain a bacterial culture and grow the same kind of bacteria in two identical culture dishes. Once the bacteria start growing, I'll add dog saliva to only one of the dishes and leave the other alone. I'll cover both dishes. Then I'll observe what happens each day for a week. Even after adding the dog saliva to one of the dishes, the bacteria continued to grow in both dishes over the course of the week. However, the bacteria in the treated dish grew more slowly than the bacteria in the untreated dish. I think I'll try something else. I'll start with two identical culture dishes, as before, and use the same kind of bacteria in each dish, but this time I'll treat one dish with dog saliva before I add the bacteria. I'll observe what happens each day for a week. What was the student’s hypothesis? Which step described the experimental set up? Identify the control What is the independent variable? What is the dependent variable? What data did the student collect? What is a possible conclusion from this experiment? Is that conclusion a fact or an inference?