Biology Test 2:Scientific Method

ClimateBiomes

Biosphere

Biology Vocabulary6. Hypothesis7. Prediction8. Control group9. Experimental Group10. Independent Variable11. Dependent Variable12. Theory13. Observation14. Double-Blind Test15. Placebo

Reading Assignment: pgs 14-19 and in old book pgs. 754-755

THE SCIENTIFIC METHOD (in detail)

1. TO START…A. Preliminary Research, reading, and background

observations

2. Statement of the questionA. Stated in a way that can be answered by observation

3. Hypothesis (a testable claim)A. NOT AN EDUCATED GUESS

B. Can be proven false be NEVER PROVEN TRUE.

C. Scientists can have evidence that “supports the hypothesis”

D. Often stated as an “if…then…” statement (this is how you write a hypothesis…

Scientific Method Continued…4. Test the Hypothesis (EXPERIMENTATION) using a

“fair test”A. Controlled Experiment – comparison between two groups that differ by only one factor

- control group – standard to which all other groups are compared

- experimental group – group that differs from the “control group” by one special factor or variableB. Variables (parts of the experiment that change)

- independent variable – the special factor in the controlled experiment that is being manipulated or changed by the researcher

- dependent variable – factor being measured as it responds to the independent variable (this is what we typically are measuring)

Scientific Method Continued…

• Enhancing Human Senses – microscopes, telescopes, computers, cameras, cell culture, growth chambers, remote sensors, lasers…etc…

Scientific Method Continued…5. Data Collection

A. Record quantitative measurements in a table (obs. made in #’s)B. Record qualitative observations (obs. made in words)C. Summarize data appropriately in a table, chart, graph, paragraph…

6. ConclusionA. A critique of the experiment.B. Identify patterns in the data and compare the results to the original hypothesisC. Ask the next question

THE SCIENTIFIC METHOD IS NEVER-ENDING!!

SCIENTIFIC METHOD WORK SHEET (students have this page?)

IDENTIFY THE DEPENDENT AND INDEPENDENT VARIABLES1.The Department of Natural resources has sold walnut shells to ARMCO Steel company. They think it will help make the furnace fires burn hotter.

2. A new substance was created by DOW chemical to help create a better picnic cooler.

3. A blood pressure medicine ROGAIN is said to cause hair growth in balding males.

4. A new protein fortified fish food from Purina is supposed to increase the weight of farm raised fish quickly.

5. A new polymer was created by Big Chemco for addition to paint. The cars painted with this should stay shiny longer.

7. Lexmark computer printers will print better if the nozzles are cleaned weekly.

8. Professor Klump suggests that exposure to a special type of radiation will cause weight loss in hamsters.

9. A combination of duct tape and bees wax will help skin wounds heal twice as fast

Scientific Method Practice

Growth hormones or no growth hormones?

Students enrolled in an agricultural studies class were asked, “do growth hormones make a difference in the muscle mass of cattle?” The students thought that yes, the more hormone provided the better off the cattle would be. The students were asked to conduct a controlled experiment to test their hypothesis. The students used 5 groups of cattle. One group was given no hormones at all. The remaining groups were given varying amounts of hormone injections. All were housed in the same facility, with the same food and water sources available. The cattle’s weights were studied for a month and the data was collected.

Mass gained (kilograms)

0Injections

1Injection

2Injections

3Injections

4Injections

35

30

25

20

15

10

Study the data below and answer the following questions.

QUESTIONS FROM DATA TABLE:• What was the problem/question?• What was the hypothesis?• What was the variable being tested?• What is the students’ control in the

experiment?• Name 4 items that should be kept the same in

this experiment to help get reliable results.• Name the independent variable.• What is the dependent variable?• State the conclusion for the students’

experiment using the results from the data table.

Identify the INDEPENDENT and DEPENDENT variables in these statements.

1. More bushels of potatoes will be produced if the soil is fertilized more.

Independent variable? __________amt. of fertilizer____________Dependent variable? ______bushels of potatoes produced_______

2.Five groups of rats are fed identical diets except for the amount of vitamin A that they receive. Each group gets a different amount. After 3 weeks on the diet, the rats are weighed to see if the amounts of vitamin A received has affected their weight.

Independent variable? __________amt. of vitamin A_______Dependent variable? _______________weight of the rats_______

3. An experiment was done with 6 groups of children to see if the score on their weekly spelling tests were affected by the number of minutes of spelling practice they had each day.Independent variable? _______minutes spent studying_______Dependent variable? ____scores on the spelling quiz_________

4. The number of pigs in a litter is determined by the weight of the mother pig (sow).

Independent variable? ________weight of the sow_______Dependent variable? _______number of pigs in a litter__________

5. The State Agriculture Department has been counting the number of foxes in Muskingum County. Will the number of foxes have any affect on the rabbit population?

Independent variable? ___number of foxes in the county__________Dependent variable? ______number of rabbits in the county_______

Double Blind Studies

• In a double-blind study, some of the participants are given the treatment, others are given a fake treatment (placebo), and neither the researchers nor the participants know which is which until the study ends (they are thus both “blind”).

• Why are these effective?

Placebos• A Placebo is a substance or procedure a

patient accepts as medicine or therapy, but which has no specific therapeutic activity.

• Basically, a fake drug

• The placebo effect – participants take the placebo and report feeling better…. How does this work? The power of suggestion?

THE BIG PICTURE• ECOLOGY - the study of relationships

(organism, environment, climate, chemistry)BIOSPHERE

ECOSYSTEM

COMMUNITY

BIOME

POPULATION

NON-LIVING COMPONENT

THE BIG PICTUREI. DIVISIONS OF THE LIVING WORLD

• BIOSPHERE- the area around the earth where life exists

- hydrosphere, lithosphere, atmosphere -14 miles thick

• BIOME- a large area characterized by certain animal and plant species as well as climate – i.e. tundra, desert, deciduous forest, savannah…

• ECOSYSTEM- all the living and non-living components of a particular geographic area -boundaries are observer defined i.e. lake, Musk. Co., Ohio, USA

• COMMUNITY- a naturally occurring group of plants and animals living in a particular area

• POPULATION - a group of organisms of one type (species) living in a particular area

• NICHE- the way of life of a species, i.e. how it obtains food, where it lives, builds a nest, escapes

• HABITAT- the physical area in which an organism lives

• CLIMATE- prevailing weather conditions

DIAGRAM THE SUBSETS OF THE LIVING WORLD

• Abiotic (NON-LIVING) Components– Sunlight– Temperature– Slope– Soil– Soil chemistry– Precipitation– Volcanoes– Rocks– Erosion– Sedimentation Rate

• Biotic (LIVING) Components– Plants– Animals– Fungus– Bacteria

ODDBALLS:VirusPrion

II. Climate – prevailing weather conditions

Factors that influence climate:1. Amount of sunlight (sun’s heat drives the

weather, uneven heating of the atmosphere)

2. daily rotation of earth

3. distribution of oceans and continents

4. elevation of land masses

A. Heating the Atmosphere: draw a simple diagram of the prevailing winds

Polar Easterly (from the east)60 N

Westerlies30 N

Tradewinds Tradewinds

30S Westerlies

60S Polar Easterly

Tropic of Capricorn

Equator

Tropic of Cancer

B. Ocean Currents and Climate• Draw prevailing ocean currents on worksheet &

add Tropics and dates

• Ocean currents effect on continental weather:– England is moderate in winter because of

clockwise movement– Currents are caused by differences in temperature,

differences in salinity, and by wind. – East coast has warm water. – West coast has cold from Arctic

C. Effects of Topography on Regional Climate

• Rain shadow effect - cool moist area flows in from the sea to replace rising warm air. The cool air rises and gives off moisture. The west side of the mountain range is wet. The east side is dry because the warming air can hold more moisture.

Biology Test 2Topics: THURSDAY

• Sci. method, • Q/Q observations, • Ind/Dep variables, (HW)• Climate, (factors determining local climate• The big picture NOTES ON Biosphere to

population• World map, with currents, and important lines • Iguana video, (notes were taken)• Biome measuring activity• Text (14-19), (360-362, very general 391-398,)• Vocabulary (6-14)

• 1. Chili peppers are theorized to have antibiotic properties.

• 2. Fevers can be reduced by chewing on the bark of willow trees.

• 3. Eating a large meal before going to bed will cause you to snore.