Chapter 1 - LAB

Suppose you study how speed affects the braking distance of a car. Match each part of the hypothesis phase with its output.

1. Formulate the hypothesis - Braking distance grows proportionally with speed. 2. Choose a scope - We will focus on how braking distance depends on speed. 3. Make a strategy for testing the hypothesis - We will brake at various speeds but keep the car and other factors constant.

What do you do in each phase?

1. Hypothesis - create a strategy formulate a hypothesis 2. Experiment - carry out the strategy collect measurements. 3. Analysis - draw graphs, evaluate the hypothesis. 4. Report - document your results; compose a report.

Why is it important to perform an experiment with a control?

1. Without a control, a positive test result could have been explained by some other factor causing a false positive. 2. Without a control, a negative test result could have been explained by some other factor causing a false negative.

Why do scientists put so much effort into documentation their experiment and analysis?

1. because other researchers must be able to repeat the experiment in order to check the results. 2. because their results are more convincing if it's clear how they came about.

what do you do in the LabSmart experiment phase?

1. carry out the strategy chosen in the hypothesis phase. 2. collect measurements in the notebook.

What do you do in the LabSmart's hypothesis phase?

1. formulate a hypothesis 2. make a strategy for the experiment.

What would be natural to do in the experiment phase if your hypothesis is: "The braking distance grows linearly with speed"?

1. get the car up to a certain speed. 2. measure the distance covered while braking. 3. record the different speeds and distances.

What do you do in the analysis phase?

1. graph the results. 2. judge whether the hypothesis is supported by the results. 3. make calculations based on the raw measurements.

Which of the following are most often included as part of a pillbug's diet?

1. plant materials. 2. leaf litter 3. rotting wood.

How should a subject be chosen to be part of a control group or an experimental group?

Selection should be random.

In the example where the hypothesis is: "The braking distance grows linearly with the speed", what should go on the y-axis?

braking distance.

When preparing your experiment for this laboratory exercise, how many substances or conditions should you test at a time.

one

Using both chambers in this experiments allows you to

perform a control experiment.

What is required of a scientific result?

1. It must be open to revision in the light of new data. 2. it has been tested using the scientific method.

How pairs of pairs of legs does a pillbug have?

7

Which question can you ask yourself to determine the independent variable of an experiment?

"What will I vary?"

What should you do when using a choice chamber to observe pill bug behavior?

1. Place only 1 substance in the test chamber 2. have control substance on the one side of the chambers. 3. make one side of the chamber a test chamber.

What should your hypothesis represent?

A possible explanation to a problem or observation.

In an experiment where tow groups are compared, one group has a treatment applied and is called the experimental group; the other group is identical to the experimental group, but has no treatment applied. This second group, with no treatment applied is called the ____ group.

control

What would be natural to do in the experiment phase if the hypothesis is: "The heavier the ball, the faster it falls"?

1. Drop different balls from a fixed height. 2. measure the weight and the falling times of different balls.

How does a pill but react when confronted with a noxious unpleasant substance?

it moves away

Suppose you have the speed on the x-axis and braking distance on the y-axis. Which graph would confirm the hypothesis Braking distance is proportional to speed.

points on a straight line through (0,0)

Suppose you hypothesis is: "The braking distance grows linearly with speed." Now let's make a strategy. Which factor will you vary in order to test the hypothesis?

speed

The hypothesis is: "The braking distance grows linearly with speed". What should be on the x-axis on the graph?

speed

In order to be of scientific value, it is important that a hypothesis should be ___.

testable.

When you formulate your hypothesis, it is important to be sure that it is an idea that can be ___

tested by scientific experiment.

Which of the following is the role of the control in an experiment?

To compare a treated or exposed group with an untreated group.

Which type of appendage is used by the pillbug to collect sensory info. about its environment?

antennae

Suppose your hypothesis is: "Braking distance grows linearly with speed". What is the dependent variable?

braking distance..

What are some phases in LearnSmart Labs' 4-phase model of the scientific method?

experiment, hypothesis.

Which type of environment is necessary for optimal respiration in pillbugs?

moist, damp

which best describes the diet of pillbugs?

omnivore

Suppose two groups of people are participating in the testing of a new drug. One group is given the drug, the other is given a placebo like a sugar pill. What is the role of the placebo group?

It is the control group.

Which of the following is true of the control group?

It is treated exactly the same as the experimental group, but without being exposed to the factor being tested.

when pill bugs are placed in a choice chamber, which of the following behaviors indicates a preference for a particular substance?

Pillbug spends more time in chamber with test substance.

What distinguishes scientific results from nonscience-based claims?

Scientific results have undergone systematic and critical testing.

If you are testing the effects of an experimental variable that is a colorless, odorless liquid, which should you choose as your control?

a liquid like plain water

Why is the testing strategy important in the design of an experiment?

A good strategy will produce accurate results.

A good scientific experiment is reproducible. What does this mean?

Anyone can conduct the same experiment in another lab and expect the same results.

Why is a good experimental design more important than a true hypothesis?

Because a good experiment yields information even when the hypothesis is disproved.

Suppose your hypothesis is: "Braking distance grows linearly with speed." What is the independent variable?

Speed

In an experiment to test a new drug, one group is given the drug in pill form while another is given a sugar pill. What is the reasoning behind giving some people a sugar pill rather than nothing at all?

The sugar pill simulates the same timing, sensation, and psychological stimulation as taking a drug in pill form.

Which best describes the pill bug's organ of respiration?

gills.

In real life, where would you usually perform the experiment phase?

in a laboratory.

Which of these topics belong in a scientific paper?

results, introduction, procedures.

which of the following is a defense mechanism of pillbugs against predation?

rolling up in a ball.

How do pill bugs detect the presence of food?

smell