Bell ringer• Define controlled variable (or control)• What are the controlled variables in this experiment?

Mike discovered that he has cockroaches living in his kitchen. He can’t decide if he wants to buy RAID “House and Garden” or RAID “Ultimate Killer”. Both are supposed to be good for killing cockroaches, but one is more expensive than the other. He puts two cockroaches in identical containers that they can’t escape from. One cockroach is sprayed for five seconds with RAID “H & G” and the other one is sprayed for five seconds with RAID “U.K.” The time it takes for the cockroaches to die is timed.

Midterm Review

1. Graphing

• Reading graphs--correctly read a specific value --compare two different values within the same graph

• Identify trends

• Find areas of increase and decrease--sharp or gradual increase and decrease

• Read values from a scatter plot

•Match table to graph

Which graph matches this table of data?

Food items Fat (in grams)

Raw clams 2

Fish sticks 10

Canned tuna 6

Lean ground beef 8

Lamb chop 4

Canned Ham 2

• Select one or more points from a table

Make a graph• Multiple bar graph• Multiple line graph• Scatter plot

For all three:--Informative title--Labeled axes--evenly spaced--Graph uses as close to full space as possible--Includes key if necessary--points correctly plotted--correctly drawn best fit line if applicable

2. What is and is not science• Science is the search for answers about the

natural world and how it works.

It is not “the truth”—science is always changing based on new information.So we don’t say we have proved a hypothesis: our hypothesis is supported.It is not simply experimentation.It cannot answer every question.

3. Observation and Inference

• Observations: what you perceive with your senses

• Inferences: conclusions drawn from observation and background knowledge

4. Variables: Independent, dependent, controlled

• Identify independent and dependent variables:--by definition--in a table--in a graph--in a purpose question--in a description of an experiment

Controlled variables

• Definition• Identify in an experiment• List controls based on understanding what

would make a comparison “fair”• Identify control group vs. experimental group• Identify what’s wrong with an experiment

5. Scientific Inquiry• Know steps of Scientific Method

• Know that the steps don’t have to be in a certain order: there is no fixed Scientific Method

• Know definition of hypothesis: --A tentative explanation for an observation, phenomenon, or scientific problem that can be tested --Must be falsifiable (can be proven false if it is false)

6. Cells

• Properties of living things• Cell Theory• Prokaryotic cells—types, role in Earth history

and present• Prokaryotic vs. eukaryotic cells