Question

a scientist might use a model
to represent objects he or she cannot see with the unaided eye.
because he or she must follow every step of the scientific methods.
because scientists cannot form hypotheses without first building a model.
because it is the only way to learn about the natural world.

although scientists do not always follow a rigid set of steps, when they plan and implement investigations they often follow a general pattern called
the theory of evolution.
the categories of science.
the scientific method
the independent and dependent variables.

background research helps a scientist in which way?
to analyze their data
to draw conclusions
to fine - tune their question and form a hypothesis
to test their hypothesis

Explanation:

First Question (A scientist might use a model):

• Option 1: Models are used to represent objects (like atoms, galaxies) invisible to the unaided eye.
• Option 2: Scientists don’t have to follow every step of the scientific method rigidly, so this is wrong.
• Option 3: Hypotheses can be formed without models, so this is incorrect.
• Option 4: Models are not the only way to learn about the natural world (e.g., direct observation), so this is wrong.

• Option 1: Theory of evolution explains biological change, not the investigation pattern.
• Option 2: Categories of science classify fields, not the investigation process.
• Option 3: The scientific method is the general pattern for scientific investigations (even if steps aren’t rigidly followed).
• Option 4: Independent/dependent variables are parts of experiments, not the overall investigation pattern.

• Option 1: Analyzing data is done after collecting it, not by background research.
• Option 2: Drawing conclusions is the final step, not related to background research.
• Option 3: Background research helps refine the research question and form a hypothesis by providing existing knowledge.
• Option 4: Testing hypotheses is done via experiments, not background research.

Answer:

A. To represent objects he or she cannot see with the unaided eye.

Second Question (Scientists’ investigation pattern):