2018 Life Science Fall Semester Exam Part 2

A variable that is purposely changed to test a hypothesis is a(n)

• observed variable.

• dependent variable.

• independent variable.

• controlled variable.

Which of the following is not a way to gain scientific knowledge?

• through experimentation

• through observation

• by making models

• by making assumptions

Observation is the process of gathering information through the senses, including sight, sound, taste, smell, and touch. Which observation is an example of sensory data?

• The mass of a pebble is 25.0 g

• A white pebble is speckled with gray

  spots.

• The volume of a pebble is 5.0 cm3.

• A pebble does not conduct an electric

  current.

Scientists think that a crater discovered on Mexico’s Yucatan Peninsula resulted from the impact of a large meteor about 65 million years ago. To find evidence for their theory, scientists examined rock samples from the crater to see if they contained shocked quartz. Shocked quartz is a type of rock produced by a high-energy impact, such as one a meteor would cause.

In addition to the Yucatan Peninsula, where should scientists look for and test rock samples?

• Mexico City

• Caribbean Sea

• Pacific Ocean

• Gulf of Mexico

Scientists conduct many types of scientific investigations. Their efforts often include fieldwork, surveys, models, and experiments. Which statement about scientific investigations is true?

• They rarely involve the collection of

  data under controlled conditions.

• They include multiple trials to increase

  the consistency of the data that are collected.

• They follow exactly the same steps

  because there is only one scientific method.

• Their primary focus seldom includes comparing or describing the unregulated world.

Sunrise and sunset data for Cocoa Beach, Florida, are shown in the table below.

Which conclusion can you accurately reach from this information?

• From January to

  July, it gets colder in Cocoa Beach each day.

• From January to

  July, there are more hours of daylight each day.

• From January to

  July, the sun rises later in the morning each day.

• From January to

  July, the sun sets earlier in the evening each day.

Scientists are extremely observant when they examine the natural world. What information do scientists collect when they observe the natural world?

• data

• investigations

• experimental designs

• explanations of experimental data

Scientists often use visual or mathematical representations to investigate items that are very large, very small, or otherwise difficult to study. What are these visual or mathematical representations called?

• experiments

• hypothesis

• models

• observations

Identifying the independent and dependent variables in an experiment will help you better interpret and convey results. What is the difference between the independent and dependent variables in an experiment?

• The independent and dependent variable is always a number, and the dependent variable is never a number.

• The independent variable is what you control, and the dependent variable is what changes as a result.

• The dependent variable is what the investigator controls, and the independent variable is what happens as a result of this.

• The dependent variable is typically found in the first column of a table, and the independent variable is typically found in the second column.

Scientific investigations include many different steps. After which step in a scientific investigation might a scientist use results to reject an existing hypothesis and form a new hypothesis?

• Analyze data

• Identify variables

• Follow a procedure

• Plan the experiment