Colleen waters the plants in her greenhouse once everyday. She wants to find out if the plants will grow more leaves if they are watered more often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she waters the other half of each type twice a day. Which is one of the controlled variables (Constants)?

Colleen waters the plants in her greenhouse once everyday. She wants to find out if the plants will grow more leaves if they are watered more often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she waters the other half of each type twice a day. What is the outcome variable (dependent variable)?

Colleen waters the plants in her greenhouse once everyday. She wants to find out if the plants will grow more leaves if they are watered more often. She counts the number of leaves on each plant before she starts. She then continues to water half of each type of plant once daily, but she waters the other half of each type twice a day. What is the test variable (independent variable)?

Christy wants to find out if the birds that visit the bird feeders in her backyard would rather build nests in birdhouses or in trees. She puts a birdhouse next to the feeder containing sunflower seeds and hangs a feeder containing cracked corn from a tree. She observes the birds’ nesting activities over the next two weeks and records her observations. Which of the following would improve Christy’s investigation?

Derek hypothesizes that a potted fern in a closed container will stay healthier than the same type of plant on an open windowsill. At the conclusion of his investigation, Derek finds that his results support his hypothesis. Which BEST explains why Derek should repeat the investigation?

When scientists conduct experiments, they share their data and conclusions with other scientists so that

Emily claims to have made a new scientific discovery. However, while conducting her experiments, she did not keep accurate records or data. Which of the following should happen next?

A controlled experiment is a means for carrying out a fair test of a hypothesis. In a controlled experiment, all of the variables that can influence the outcome variable (dependent variable) of the experiment are controlled or held constant, except for the test variable (independent variable). Which of the following hypotheses would NOT be tested using a controlled experiment?

A scientist is testing a new design for the blade of a wind turbine used to generate electricity. Which of the following is the best first step for the scientist to take?

Sara is studying the human skeletal system. Her classroom has a model skeleton. What main advantage does a model skeleton have over a drawing of a skeleton?

Bernard is designing a new boat. His first step is to use a computer modeling software to create and test his design in simulated weather and wave conditions. How does Bernard benefit from using a computer-generated model instead of a full-sized boat?

Coral is making a model of a water molecule using colored balls and sticks. Which of the following best describes an advantage that her ball-and-stick model has over a model drawing of a water molecule?

Susan noticed that hummingbirds in her yard visited all the flowers, but especially seemed to like the red trumpet-shaped ones. She read that they use the nectar in the flowers for food. She assumed that since the parents were eating nectar, they must feed their babies nectar as well. To her surprise she saw hummingbirds bringing small insects and spiders to feed the young hummingbirds. How does this new evidence affect her original assumption?

Which of the following statements is true?

Although a scientific theory is well supported and widely accepted, what might cause it to change?

The theory of evolution describes how organisms change over time. Scientists now use information in the DNA of living organisms to understand how they are related. The theory of evolution was developed before scientists discovered DNA; however, these new data still fit with and support the theory. What does this sequence of events tell us about the theory of evolution?

In the early 1900s, a scientist named Alfred Wegener proposed the idea that all the continents were once joined together into one supercontinent, which he called Pangaea. At first, this theory was rejected by society, but now it can be found in textbooks. Which of the following most likely caused people to accept the theory that the continents were once all connected?

One of the scientists who proposed the theory that the Sun was the center of our Solar System was Copernicus (HELIOCENTRIC MODEL). This was different from the accepted theory of the time, which stated that Earth was the center of our solar system (GEOCENTRIC MODEL). How was the theory that the Sun was the center of the Solar System finally accepted?

Which of these items must be supported by empirical evidence?

Which of these answers best describes a scientific theory?

Which of these answers describes a scientific law?

Scientists use different types of tools to investigate how and why things happen. Here are some examples of these tools: • a diagram of a food chain in the Everglades • a plastic replica of the human digestive system • a mathematical equation for finding the speed of an object Which word describes all of these examples?

Dr. Simmons wants to make sure her scientific investigation is considered good. She knows that for an experiment to produce valid results, it must adhere to accepted methods. Which procedure would she not include as part of her valid scientific experiment?