Biology Junction Team - BIOLOGY JUNCTION

Scientific Method Solution

Scientific Method Solution

+ N + + + + + + + + + + T + + + O E + + + + + + + + N + + + A I + X H Y P O T H E S I S C C T E + P + + + + D + L + R O H A A L + E + + N + O + E + N A V + D B + R E + R + P + + C R R + E + A P I T + E + S + L T E + + R E I N M A + T I + U + S + + D R O R T E A + S + S + B + N + C O A A B N + Y + I + O I + + + B R L V + T L + O + + + + + L + E S + + + A + N + + T N E D N E P E D + N + + + + + + + + + + + + + + A + + T E S T I N G H P A R G + + + (Over,Down,Direction) ANALYSIS(13,14,N) CHART(1,4,S) CONCLUSION(15,3,S) CONTROL(6,10,NE) DATA(4,6,NW) DEPENDENT(11,13,W) ERRORS(4,7,SE) EXPERIMENT(3,2,SE) GRAPH(12,15,W) HYPOTHESIS(5,3,E) INDEPENDENT(3,11,NE) OBSERVATION(2,11,N) REPEATABLE(14,4,SW) TABLE(12,8,SW) TESTING(1,15,E) VARIABLE(10,11,NW)

Scientific Method Notes

Scientific Method
All Materials © CmassengaleHow can we determine if something is a fact or an opinion? How can we determine an answer to a problem? The answer is use the scientific method.What is the Scientific Method? It is a series of steps used to help solve a problem.

Step 1. Make an Observation. After making an observation of the natural world, define the problem and make sure only one problem is being studied. ALL scientific experimentation starts with observation.
Step 2. Research the problem (question). Use all available resources to collect data on the subject being covered. Libraries, Internet, books, magazines, personal interviews, etc.
Step 3. Develop a hypothesis (educated guess). Make it a short definitive statement. It may be an “if” then” statement. The “if” part will become the hypothesis and the then part should be the results received at the end of the controlled experiment. Remember your hypothesis can be changed if the results do not support it.
Step 4. Develop a controlled experiment. A controlled experiment is an experiment that contains only one experimental variable. An experimental or independent variable is the thing being tested (what the scientist changes). Everything else in the experiment or all other variables must be the same. These variables are also called the controlled variables. Keeping these variables the same allows the experimenter to show that it was the experimental variable that caused the results. The dependent variable is what changes when the independent variable changes – the dependent variable depends on the outcome of the independent variable. Data should be organized into charts, tables, or graphs.
Step 5. Analyze the data and come up with a conclusion. Data may be quantitative (numbers) or qualitative (appearance, properties, etc.). The conclusion may or may not support the hypothesis. Additional experimentation must then take place to build documentation concerning the problem. If the hypothesis is proven wrong, change the hypothesis, not the data. Scientists must be unbiased.
WHAT FOLLOWS: Scientific research must be published, but first it must be reviewed by peers (other scientists) and verified for accuracy. Research may result in a scientific theory or law.

Example:

Observation:	Toaster stops working.
Question/Research:	What is wrong with the toaster? (Read toaster Manual.)
Hypotheses:	(1) It is unplugged. (2) The unit is burned out.
Experiments:	(1) Check the plug. (2) Take the toaster apart and look at the heating wires.
Results & Conclusion:	If it was unplugged the first hypothesis is supported, if the wires inside are broken, then the second hypothesis is supported.

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Scientific Method & Blood Flow

Scientific Method & Blood

INTRODUCTION:

In this lab you will learn to form a hypothesis, conduct experiments around that hypothesis, and collect and analyze data. One of the most important characteristics of modern science is its quantitative approach to solving problems. One of the first scientists to use quantitative methods was William Harvey, who discovered that blood circulated through the body. At the time Harvey began his work, anatomists believed that the liver produced blood from the food that the body consumed. The blood was then carried by veins to the heart, purified in the lungs, and then pumped to the various organs of the body, where it was consumed. Harvey measured that the left ventricle of the heart held roughly 100 ml of blood. He also measured that the heart beats an average of 64 times per minute.

QUESTION 1:

From the information above, and assuming that 1 ml of blood weighs 1 g, how much blood would the body need to produce per hour in ( g/hr.) to replace the blood consumed by the organs? _______g/hr.

Harvey hypothesized that the same blood must circulate continuously throughout the body.

MATERIALS:

Watch with second hand, or clock

PROCEDURE:

While sitting quietly at your desk, find the pulse in your wrist and count the beats for one minute. You and your lab partner can do this on yourselves, or each other. Record the names of both subjects and their beats per minute heart rate on DATA TABLE 1 as sample 1.
Repeat step 1 two more times for each subject. Record the data in the appropriate place on DATA TABLE 1.
Calculate the average pulse rate for each subject and record the results on DATA TABLE 1.

How do you think standing or holding your breath will affect your pulse rate? ______________________________________________________

QUESTION 2:

Choose one of these activities and formulate a hypothesis about its effect on pulse rate. What is the independent variable? What is the dependent variable?

Hypothesis _______________________________________________

Independent Variable _______________________________________

Dependent Variable ________________________________________

Repeat steps 1, 2, and 3 for each subject, this time with the subjects standing or holding their breath. Record your data and calculations in the appropriate DATA TABLE

DATA TABLE 1: Resting heart rate
	NUMBER OF BEATS PER MINUTE			AVERAGE NUMBER OF BEATS PER MINUTE
SUBJECT	sample 1	sample 2	sample 3

DATA TABLE 2: Heart rate standing
	NUMBER OF BEATS PER MINUTE			AVERAGE NUMBER OF BEATS PER MINUTE
SUBJECT	sample 1	sample 2	sample 3

DATA TABLE 3: Heart rate holding breath
	NUMBER OF BEATS PER MINUTE			AVERAGE NUMBER OF BEATS PER MINUTE
SUBJECT	sample 1	sample 2	sample 3

Conclusion: Compare your data from step 4 with your data from step 3.

1. How do your results in step 4 compare with the hypothesis you made?

2. What measurement did you use as a control in this investigation?

3. What are some possible sources of error in this experiment?

Scientific Method puzzle

Scientific Method

Find each term and then define it on the back of the paper.

ANALYSIS	CHART	CONCLUSION
CONTROL	DATA	DEPENDENT
ERRORS	EXPERIMENT	GRAPH
HYPOTHESIS	INDEPENDENT	OBSERVATION
REPEATABLE	TABLE	TESTING
VARIABLE

Solution

Scientific Laws

Scientific Laws, Hypotheses, and Theories

Scientific Theory versus “Just a theory” Layman’s term:

In layman’s terms, if something is said to be “just a theory,” it usually means that it is a mere guess, or is unproved. It might even lack credibility. But in scientific terms, a theory implies that something has been proven and is generally accepted as being true.

Scientific Meanings:

SCIENTIFIC LAW: This is a statement of fact meant to describe, in concise terms, an action or set of actions. It is generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation. Scientific laws are similar to mathematical postulates. They don’t really need any complex external proofs; they are accepted at face value based upon the fact that they have always been observed to be true. Specifically, scientific laws must be simple, true, universal, and absolute. They represent the cornerstone of scientific discovery, because if a law ever did not apply, then all science based upon that law would collapse. Some scientific laws, or laws of nature, include the law of gravity, Newton’s laws of motion, the laws of thermodynamics, Boyle’s law of gases, the law of conservation of mass and energy, and Hook’s law of elasticity.

HYPOTHESIS: This is an educated guess based upon observation. It is a rational explanation of a single event or phenomenon based upon what is observed, but which has not been proved. Most hypotheses can be supported or refuted by experimentation.

THEORY: A theory is more like a scientific law than a hypothesis. A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers. One scientist cannot create a theory; he can only create a hypothesis. Theories may be expanded or modified with further scientific evidence.

Development of a Simple Theory by the Scientific Method:

Start with an observation that evokes a question: Broth spoils when I leave it out for a couple of days. Why?
Using logic and previous knowledge, state a possible answer, called a Hypothesis: Tiny organisms floating in the air must fall into the broth and start reproducing.
Perform an experiment or Test: After boiling some broth, I divide it into two containers, one covered and one not covered. I place them on the table for two days and see if one spoils. Only the uncovered broth spoiled.
Then publish your findings in a peer-reviewed journal. Publication: “Only broth that is exposed to the air after two days tended to spoil. The covered specimen did not.”
Other scientists read about your experiment and try to duplicate it. Verification: Every scientist who tries your experiment comes up with the same results. So they try other methods to make sure your experiment was measuring what it was supposed to. Again, they get the same results every time.
In time, and if experiments continue to support your hypothesis, it becomes a Theory: Microorganisms from the air cause broth to spoil.

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