Today’s Catalyst! (Bellwork)

• What are the two types of data and what is the difference between the two?

• What should a graph (any type) include?

• What type of graph shows continuous data? Give an example of a relationship that could be shown on this type of graph.

International System of Measurement (SI)

• Note descriptions on page 1058-1059 of your book

• 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 10kilo (k) – kilometers (km) 1000 metershecto (h) – hectometers (hm) 100 metersdeca (da) – decameters (dam) 10 metersBasic unit (m, L, g) – meter (m) 1 meterdeci (d) – decimeter (dm) 0.1 metercenti (c) – centimeter (cm) 0.01 metermilli (m) – millimeter (mm) 0.001 meter

King Henry Died By Drinking Chocolate Milk

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

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

•Make at least 3 observations about this picture.

•Make at least 3 inferences about this picture.

• Make three observations and inferences with this new information

• Does the new information change your responses?

What does this final picture do to your previous inferences?

What does this picture do to your previous inferences?

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

Number 5 - Record and Analyze Data

• 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

Number 6: State the Conclusion

• State the conclusion and draw inferences that serve as a starting point for a new experiment.

• Scientists use reasoning to figure out answers to their questions based on observations gathered through their senses and from research that already was conducted by the topic.

Number 6: State the Conclusion

• Scientists understand the theories are always subjected to change as new data becomes available

• What is an inference?– Making a conclusion based on reasoning from

evidence and theories– Deductive reasoning: applying specific

theories to make a conclusion about evidence (top-down)

– Inductive reasoning: broad generalization from specific observations (bottom-up)

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

7 Steps of the Scientific Method

• Number 7 - Repeat– No matter what happened!

Types of Conclusions

– Fact – basic statement known by actual observation and experiment•Something that is true only under

certain conditions•Observable phenomenon that can be

confirmed by scientists many times

•Ex) a proven hypothesis

Types of Conclusions..

– Scientists Form a Theory –• An explanation of some aspect of the

natural world that can incorporate facts, laws, inferences, and tested hypotheses.

• Explains why certain facts and laws exist..• Theories can be modified over time as

new facts are discovered.

•Examples: Evolution, Big Bang Theory

Laws• Law: A logical

relationship between two or more things that is based on a variety of facts and proven hypothesis.

• Often a mathematical statement of how two or more quantities relate to each other.

Laws• Example: F= m*a

(Newton’s 2nd law..greater force means greater acceleration)

• Explains how nature behaves, not why it behaves that way

Fact vs. Theory

• Which is Fact…Which is Theory?– Dinosaurs were cold blooded.– The caterpillar is 2.5 cm long.

Identifying Study ComponentsA 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:

A. I wonder why the dog's wound doesn't become infected.B. The dog's saliva must prevent the growth of infection-causing bacteria.C. 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.

D. 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.

E. 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 ComponentsA 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:

A. I wonder why the dog's wound doesn't become infected.B. The dog's saliva must prevent the growth of infection-causing bacteria.C. 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.

D. 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.

E. 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 experimentalexperimental 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?

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 Technological Design

Identifies a problem – asks a question

Identifies a problem or need

Researches related information

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 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

Scientific Investigation vs Technological Design

Scientific Investigation vs. Technological Design

https://www.youtube.com/watch?v=3o9rsq3TYQk