NOS RETAKE 2526

Cheyanne wants to investigate the effects of plant moisture on the growth of caterpillars. She fills three identical boxes with an equal number of a kind of leaf that caterpillars eat. She keeps the leaves in the first box dry, sprays the leaves in the second box with two sprays of water, and sprays the leaves in the third box with four sprays of water. She then adds four caterpillars to each box. Every day the length of each caterpillar is measured and recorded, and the results are averaged. What is the test variable (independent variable) in this experiment?

THE INDEPENDENT VARIABLE CHANGES IN THE EXPERIEMENT.

THE DEPENDENT VARIABLE IS THE DATA WE MEASURE.

• The amount of water put on the leaves

• The number of leaves in each box

• The change in legnth of the caterpillars

• The amount of caterpillars in each box

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Hayden and Antonio conducted an experiment. A basic principle for scientific research is that the experiment must be able to be replicated. Cody wants to replicate the experiment. What happens when an experiment is replicated?

REPLICATION: COPY SOMEONE ELSE'S EXPERIMENT.

REPETITION: REPEAT YOUR OWN EXPERIMENT.

• A publisher accepts the experimental results for printing.

• No one in the scientific community agrees with the methods or results.

• Other scientists perform the same experiment and get comparable results.

• The scientific researcher preforms the experiment many times and gets the same results.

London is experimenting with different fertilizers. He plants five fields of wheat and applies different fertilizers to each field. At the end of the planting season, he harvests the fields and counts the bushels of wheat that each field produced. What is the independent variable in this experiment?

THE INDEPENDENT VARIABLE CHANGES IN THE EXPERIEMENT.
THE DEPENDENT VARIABLE IS THE DATA WE MEASURE.

• the type of fertilizer used

• the wheat

• the bushels of wheat that are counted

• the amount of sunlight

Tags

NGSS.MS-ETS1-1

In an experiment concerning the growth of mice in a scientific lab, scientists have four groups of mice. Each group of mice get different amounts of the same specialized mouse diet. The mice are weighed daily, and the results are recorded. Which is the dependent variable in this experiment?

THE INDEPENDENT VARIABLE CHANGES IN THE EXPERIEMENT.
THE DEPENDENT VARIABLE IS THE DATA WE MEASURE.

• the type of mouse diet

• the amount of food the mice get each day

• the weight of the mice

• the housing of the mice.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

The fine people at Apple are deeply invested in developing the very best battery for their iPhones. The iPhone 11 Pro Max has the newest, most advanced battery they can offer. To test these batteries, the electrical engineers developed six different battery prototypes. They tested the batteries in iPhone 11 Pro Max phones to by running YouTube videos and recording how long the phones stayed on until the batteries ran out. What is one of the constant variables in this experimental process?

CONTROL VARIABLE: TEST GROUP THAT IS NOT CHANGED. USED FOR COMPARISON.

CONSTANT VARIABLE: THINGS THAT ARE THE SAME IN EVERY TEST GROUP AND TRIAL OF AN EXPERIMENT.

• the iPhone 11 Pro Max phones

• the different battery prototypes

• the amount of time each battery lasted

• the reaction of buyers to the battery life

A scientist used a model to predict the path of a hurricane. The hurricane followed a similar path but did not follow the exact path that was predicted. How does this example demonstrate a limitation of models?

BENEFIT: HOW SOMETHING IS HELPFUL OR USEFUL

LIMITATION: SOMETHING THAT CANNOT BE DONE

• Models cannot be used to predict events

• Models can be used to predict weather events before the event occurs

• Models cannot account for how every factor may suddenly change.

• Models can only be used to show physical structures,not events such as hurricanes.

Tags

NGSS.MS-ESS2-6

NGSS.MS-ESS3-2

Scientists create both scientific theories and scientific laws as they make observations and conduct experiments about the natural world. Which of the following statements most accurately compares the difference between scientific theories and scientific laws?

SCIENTIFIC THEORY: (WHY DOES IT HAPPEN?)

SCIENTIFIC LAW: (WHAT HAPPENS?)

• Scientific laws are based on evidence, while scientific theories are not.

• Scientific theories involve only biology, while laws involve all types of science.

• Scientific theories involve mathematical equations, while scientific laws are based on observations.

• Scientific theories are ideas that explain natural events, while scientific laws more reliably predict natural events.

Science is not always conducted in a controlled laboratory with experiments. Sometimes scientists will conduct investigations by gathering data and observations from the environment to learn more about the natural world. What is the key difference between a controlled experiment in a lab and an observation and data collection based investigation?

WHICH ONE HAS CONTROLLED VARIABLES?

WHICH ONE IS OBSERVATIONS ABOUT THE WORLD?

• Investigations are always conducted by amateurs and experiments are always in a lab with multiple doctors.

• Investigations do not have controlled variables but experiments do have identified and controlled variables.

• Experiments do not have controlled variables but investigations do have identified and controlled variables.

• Experiments and investigations are essentially the same. Either term can be used to describe the pursuit of scientific knowledge.

The development of microscopes allowed scientists to investigate living things in greater detail. Through many investigations, scientists found evidence that all living things are made of one or more basic units that divide to form new units. Scientists used their evidence to explain the relationship between these “building blocks of life” and the organisms to which they belong. What are these explanations called?

SCIENTIFIC THEORY: (WHY DOES IT HAPPEN?)

SCIENTIFIC LAW: (WHAT HAPPENS?)

• Theories because they explain how living organisms are organized.

• Laws because they explain how living things are organized.

• Experiments because scientists used microscopes.

• Investigations because there is no proof, only guesses.

Tags

NGSS.MS-LS1-1

NGSS.MS-LS1-2

NGSS.MS-LS1-3

Holly spent the entire summer in Iowa watching the prairie dogs in a field. She observed that the rodents seem to have a guard that watched out for predators. The guards make a certain noise when a hawk comes by and it sounds like they make a different noise when a snake is spotted. Overall, 76 hawks were spotted and 32 snakes were spotted. How could Holly's summer activities be described?

INVESTIGATIONS ARE OBSERVATIONS, DATA MAY BE COLLECTED.

EXPERIMENTS ARE CONTROLLED AND HAVE VARIABLES.

• This is an investigation because Holly only used observations and data without variables to gather scientific information.

• Holly conducted an experiment. The independent variable is the type of predator, the dependent variable is the sound the prairie dog makes.

• Holly used a theory to guess why the prairie dogs are making the noises when they see predators.

• Holly created a new law that says prairie dogs always make noise when they see predators.

Tags

NGSS.MS-LS2-4