| Safety & Equipment Study Guide | |||||||||||||||||||||||||||
Be able to recognize pictures of the following equipment:
Know the best solution for each of these safety problems:
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Category: My Classroom Material
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 |
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| 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 |
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| 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?
Salamander Key
| Dichotomous Key to Salamanders |  |
Introduction:
A dichotomous key is constructed of a series of couplets, each consisting of two separate statements. For example: couplet 1. Seeds round soybeans
1. Seeds oblong 2 (this statement indicates that you go to couplet “2”)
couplet 2. Seeds white northern beans
2. Seeds black black beans
By reading the two statements of each couplet, you progress through the key from typically broad characteristics to narrower characteristics until only a single choice remains. As long as the correct statement of each couplet is chosen, and the unknown organism is included in the key, a confident identification is usually achieved. Many types of organisms can be identified using a dichotomous key. In this lab, you will identify salamanders.
Materials:
pictures of various salamanders, dichotomous key, metric ruler, pencil
Procedure:
- Use the dichotomous key provided to identify the salamanders in Figure 1.
- Write the pathway you took to get to the name of the salamander next to the drawing.
- Write the correct name for the salamander on the line below each picture.
Figure 1 – Types of salamanders
Key to the Salamanders:
| 1 | a | Hind limbs absent | Siren |
| b | Hind limbs present | Go to 2 | |
| 2 | a | External gills present in adults | Mud puppy |
| b | External gills absent in adults | Go to 3 | |
| 3 | a | Large size (over 7 cm long) | Go to 4 |
| b | Small size (under 7 cm long) | Go to 5 | |
| 4 | a | Body background black, large white spots irregular in shape and size completely covering body & tail | Tiger salamander |
| b | Body background black, small, round, white spots in a row along each side fro eye to tip of tail | Spotted Salamander | |
| 5 | a | Body background black with white spots | Go to 6 |
| b | Body background light color with dark spots and or lines on body | Go to 7 | |
| 6 | a | Small white spots on a black background in a row along each side from head to tip of tail | Jefferson salamander |
| b | Small white spots on a scattered throughout a black background from head to tip of tail | Slimy salamander | |
| 7 | a | Large irregular black spots on a light background extending from head to tip of tail | Marbled salamander |
| b | No large irregular black spots on a light background | Go to 8 | |
| 8 | a | Round spots scattered along back and sides of body, tail flattened like a tadpole | Newt |
| b | Without round spots and tail not flattened like a tadpole | Go to 9 | |
| 9 | a | Two dark lines bordering a broad, light mid-dorsal stripe with a narrow median dark line extending from the head onto the tail | Two-lined salamander |
| b | Without two dark lines running the length of the body | Go to 10 | |
| 10 | a | A light stripe running the length of the body and bordered by dark pigment extending downward on the sides | Red-backed salamander |
| b | A light stripe extending the length of the body, a marked constriction at the base of the tail | Four-toed salamander |
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.
Example:
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Puzzle Solution – Cell Reproduction
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