Today’s Schedule (Day F) 8:03 – 9:23 Testing 9:26 – 9:56 Period 1 9:59 – 10:32 Period 2 10:35 - 11:08 Period 3 11:11 - 11:44 Period 4 11:47 – 12:20 Period

Today’s Schedule (Day F)• 8:03 – 9:23 Testing• 9:26 – 9:56 Period 1• 9:59 – 10:32 Period 2• 10:35 - 11:08 Period 3• 11:11 - 11:44 Period 4• 11:47 – 12:20 Period 5• 12:23 – 12:56 Period 6• 12:59 – 1:32 Period 7• 1:35 – 2:09 Period 8• 2:12 – 2:45 Period 9

Friday, September 19 (Day F)Objective: S8.A.2 Learn the

Processes, Procedures and Tools of Scientific Investigations

Quiz

Finish Survey Research Projects

Don’t Forget Homework: MySkillsTutor.com Bar Graphs

Test next Thursday

Take Makeup quizzes & review for quiz tomorrow

Tomorrow: make-up quizzes

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DT per Hour

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Temperature

Bacterial Doubling Time (DT) vs. Temperature

Does Temperature Affect the Rate of Bacterial Reproduction?

1. 1. No, the data in the table do not support the student’s hypothesis because bacterial reproduction increases as the temperature increases only at temperatures below 30.5 C. At temperatures greater than 30.5 C, the bacterial reproduction rate decreases as the temperature increases.


1. 2. This bacteria has a maximum reproduction rate at a single temperature near 30.5 C.


1. 3. Any one of the following factors could affect the reproduction rate of the bacteria: the type of nutrient medium used, the moisture level of the nutrient medium, the presence or absence of light, the type of bacteria used, whether or not the Petri plates were sealed, whether or not a single person was counting the bacteria.


1. 4. No, I am not satisfied with the data because the researcher did not explain how he eliminated the possible variables listed in question #3. Also, there is no mention of a control group.


1. 5. Suppose that we want to test the hypothesis that this type of bacteria reproduces the most at a single temperature. We would need to have several experimental groups and one control group for this experiment. The data from the experiment in the book suggests that this bacteria grows well at 30.5 degrees Celsius.


1. 5. (continued) So, we would use this temperature for growing our control group cultures. For our control group, we would put three Petri plates with the bacteria at 30.5 C. Then, we would grow our experimental groups (three Petri plates in each group) at perhaps three different temperatures near to 30.5C, like 26C, 28C, and 32C.


1. 5. (continued) In order to have a controlled experiment (that is, one with only one variable) we would need to make sure that all groups have the same nutrient medium, same moisture content, same light level, same type of bacteria, same type of Petri plates, same person counting the bacteria, etc.

Control

30.5 C

Exp 1

26 C

Exp 2

28 C

Exp 3

32 C

Prefixes in the SI

Prefix Symbol Multiplier Exp

yotta- Y 1 000 000 000 000 000 000 000 000 10+24

zetta- Z 1 000 000 000 000 000 000 000 10+21

exa- E 1 000 000 000 000 000 000 10+18

peta- P 1 000 000 000 000 000 10+15

tera- T 1 000 000 000 000 10+12

giga- G 1 000 000 000 10+9

mega- M 1 000 000 10+6

kilo- k 1 000 10+3

hecto- h 100 10+2

deca- da 10 10+1

Prefixes in the SI

Prefix Symbol Multiplier Exp

deci- d 0.1 10-1

centi- c 0.01 10-2

mili- m 0.001 10-3

micro µ 0.000001 10-6

nano- n 0.000000001 10-9

pico- p 0.000000000001 10-12

femto f 0.000000000000001 10-15

atto- a 0.000000000000000001 10-18

zepto- z 0.000000000000000000001 10-21

yocto- y 0.000000000000000000000001 10-24

Factor Name Symbol

1024 yotta Y

1021 zetta Z

1018 exa E

1015 peta P

1012 tera T

109 giga G

106 mega M

103 kilo k

102 hecto h

101 deka da

Factor Name Symbol

10-1 deci d

10-2 centi c

10-3 milli m

10-6 micro µ

10-9 nano n

10-12 pico p

10-15 femto f

10-18 atto a

10-21 zepto z

10-24 yocto y

Metric System Prefixes

kilometer meter centimeter milimeter

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The Scientific Method

• Hypothesis: a testable answer to a scientific question– Example: My female students are more daring

than my male students


• Infer: to make a guess that is based on observations– Example: I infer that ___________ didn’t get

enough sleep because they are sleeping in class.


• Variable: anything that can change during an experiment– Temperature– Light– Age


• A controlled experiment: one in which only one variable changes at a time


• Control group: a group that serves as a reference for other groups

• Experimental group: a group in which scientists deliberately change one variable.


• Theory: an explanation of things or events based upon many observations and experiments. – A working model which may or may not be

true– Cell Theory: all living things are made of cells.– Evolutionary Theory– The “Big Bang” Theory


• Law: a statement of how things work in nature that seems to be true all the time. – A “fact of life”– First Law of Thermodynamics: Energy can be

changed from one form to another, but it cannot be created or destroyed.

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DT per Hour

20.5 30.5 36 39.2

Temperature

Bacterial Doubling Time (DT) vs. Temperature

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Marijuana cocaine Heroin

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Documents

Today’s Schedule (Day F) 8:03 – 9:23 Testing 9:26 – 9:56 Period 1 9:59 – 10:32 Period 2 10:35 - 11:08 Period 3 11:11 - 11:44 Period 4 11:47 – 12:20 Period