Science Midterm Review

You have a hypothesis that of people ages 4 to 35, teenagers will like a new drink called SugarHi better than any other age group. You want to survey 40 people for their opinions about the drink, but you are unsure how many people to survey from each age group. Which of the answer choices below represents the most fair way to collect the data? Number of People Surveyed in Each Age Group 4-11 yr old 12-19 yr old 20-27 yr old 28-35 yr old ? ? ? ?

10 10 10 10

Mario believes he has found the reason that some things glow in the dark while others do not. What is the most important thing he will need to do before his theory will be accepted by other scientists?

Develop tests and experiments that can be repeated to prove his theory.

A scientist performs an experiment that indicates anti-inflammatory medications can lead to liver failure if they are used on a daily basis. The scientist publishes her results in a scientific journal. What should be done before the scientific community accepts her results as being accurate?

Different scientists should repeat the experiment to see if they can get the same results.

Nick is conducting a controlled experiment to test whether music helps daisies grow faster. Below are the steps to Nick's experiment: 1. Plant daisies in two separate flowerpots. 2. Place flowerpot 1 in a green room with music. 3. Place flowerpot 2 in a similar green room without music. 4. Give the daisies the same amount of food and water each week. 5. Measure the growth of the daisies. 6. Draw conclusions based on the data collected. Which is the experimental group in Nick's experiment (which group did the variable affect)?

Flower pot 1

The scientific theory of plate tectonics states that the Earth's crust is composed of many plates, or slabs of rock. Interactions of these plates have created different landforms, or geologic features. Which of the following statements provides evidence for this theory?

Fossilized marine creatures can be found at the top of the Himalayan mountains.

Scientific knowledge must be supported by evidence. An idea that is not supported by evidence but is made to appear scientific in order to make people think it is a part of science is called pseudoscience. Pseudoscience cannot be considered scientific because pseudoscientific ideas lack evidence. Which of the following ideas is considered scientific?

Genes are made up of DNA and affect how an organism looks

Jay wants to know how the amount of acidity in rainwater influences the weathering rate of limestone. To answer his question, Jay performs an experiment in which he soaks identical pieces of limestone in 200 mL of different carbonic acid solutions. The pH of the solutions range from 3.0 to 5.5. After performing his experiment once, he reports his data and draws a conclusion. What can Jay do to improve the reliability and accuracy of his data?

He can repeat his experiment multiple times and ask someone else to replicate his experiment.

Jami is doing an experiment to find out how temperature slows down or speeds up the sprouting of bean seeds. To prepare for the experiment, she plans to put soil into three foam cups and place six seeds in each cup. When Jami performs the experiment, which of the following should she keep the same for all of the cups of beans? I. the amount of sunlight II. the amount of water III. the temperature IV. the amount of fertilizer

I, II, and IV only

In ancient times, many people believed in a geocentric model of the solar system, where the Earth was the center of the system. During the 16th and 17th centuries, men such as Copernicus, Kepler, and Galilei theorized or found evidence that the Sun was actually the center of the solar system. However, despite convincing evidence, this idea was not accepted until some time later.

It is difficult to change a commonly held belief.

A geologist fills three identical funnels with three different sizes of sandstone. Then, the geologist pours 500 mL of water into each funnel and measures how long it takes for the water to stop draining out of the bottom of the funnels. A biologist cuts an African violet leaf into six equal-sized pieces. Then, the biologist carefully places the cuttings on six different petri plates, each filled with a different substance, and monitors the growth of the cuttings over the next several weeks. A physicist places three identical glass rods in different beakers, each filled with a different liquid. Then, the physicist measures the angle of refraction in each scenario. Which of the following statements is true based on the above information?

Laboratory experiments are a useful form of scientific investigation in many different fields of science.

Eddie is going to do an experiment to find out which freezes more easily—distilled water or salt water. In what order should he do the following steps in his experiment?

Make a prediction about which liquid will freeze first. ↓ Fill two beakers with 250 mL of distilled water. ↓ Dissolve 30 grams of salt in one of the beakers ↓ Place both beakers in a freezer and observe which liquid freezes first. ↓ Write a report on his findings.

Juan is interested in finding out whether hummingbirds are attracted to some flowers more than others. In what order should Juan perform the steps of his experiment?

Make a prediction about which flowers hummingbirds are most attracted to. ↓ Create a garden of different flowers. ↓ Observe how many times hummingbirds visit each flower. ↓ Record his observations. ↓ Write a report on his findings. Create a garden of different flowers.

According to the scientific method, what should you do before you formulate a hypothesis?

Make observations and identify the problem.

While David was riding his bike around the circular cul-de-sac by his house, he wondered if the constant circular motion was having any effect on his tires. What would be the best way for David to investigate this?

Measure the wear on his treads before and after riding a certain number of laps.

You have decided to do an experiment to learn if a certain type of cactus will grow better in a dark closet or a sunny window. To begin your experiment, you place one cactus in a dark closet and one cactus in a sunny window. Over the next month, you record data about the cacti and their appearance every day. At the end of the month, you determine that the cactus in the sun is alive but didn't grow and that the cactus from the dark closet is alive and grew one centimeter. Can you conclude that a dark closet is better for this type of cacti's growth?

No, you need to repeat an experiment multiple times before accepting a conclusion.

Nolan and Hunter are studying heat flow, so they design the following apparatus. The apparatus consists of two identical glass cylinders connected by a glass tube. During their experiment, Nolan and Hunter simultaneously pour hot water in the tank on the left and cold water in the tank on the right. Then, they seal the tops of the cylinders and allow the water in the tanks to intermingle through the glass tube. To determine if heat is transferred, Nolan wants to place his hands in each tank of water at the beginning and end of the experiment. Hunter wants to use a thermometer to measure the temperature in each tank at the beginning and end of the experiment. How do Nolan and Hunter's proposed methods compare?

Nolan's method would allow him to make a descriptive observation. Hunter's method would allow him to include numbers in his data.

Sarah wants to know if mice prefer peanut butter over cheese. In what order should she do the following steps?

Predict which food the mice will prefer. ↓ Place a bowl of peanut butter and a block of cheese next to each other in a mouse cage. ↓ One at a time, place ten mice in the cage and observe which food they prefer. ↓ Write a report on her findings.

What is the difference between replication and repetition?

Repetition occurs when multiple sets of measurements are made during one scientific investigation. Replication occurs when a scientific investigation is reproduced by another person.

Rick is a biologist who hypothesized that squid would swim faster in warm water than in cold water. Rick conducted his experiment. He discovered that squid swim at the same rate in warm and cold temperatures. What should Rick do next?

Report his findings

Which of the following best describes how science is different from other activities involving thought?

Science specifically involves observing, asking questions, and doing experiments on natural phenomena.

At one time, most people believed that the Universe was static, meaning it did not change. When larger and better telescopes were invented in the early 1900s, however, it was discovered that light from objects in space shifted toward longer wavelengths. Scientists concluded that only an expanding Universe could explain this shift. Which of the following statements is supported by this example?

Scientific knowledge can change when new evidence or interpretations arise.

Scientific theories are explanations for naturally occurring events or phenomena. Although scientific theories require extensive observations and experimentation, they can change over time as new evidence is discovered. Scientific laws are principles that are also based on extensive observations and experimentation. Although scientific theories can develop into laws, a theory can only be declared a law if it is proven to be without exception under certain stated conditions. Which of the following is true regarding scientific theories,laws, and knowledge?

Scientific theories and laws develop from the acquisition of scientific knowledge

Joseph has hypothesized that sound travels in waves. If he were following the scientific method, what should he do next?

Test the hypothesis.

Jenny dissolves as much salt as she can in 100 mL of room-temperature water. She learned in class that less salt will dissolve in cold water than in hot water. Jenny adds some ice to the salt water and observes what happens. What effect will adding the ice to the solution have on the amount of salt that can be dissolved into it?

The effect is unpredictable because the ice changes two variables at the same time.

Shelly wants to know if hummingbirds prefer honey, sugar, or corn syrup. She creates three solutions of equal sweetness. One solution is made of honey and water; the second is sugar water, and the third is corn syrup and water. She places three hummingbird feeders side-by-side outside a window. To make sure she could tell them apart, she puts each solution in a different-colored feeder: one is red, one is yellow, and one is blue. Shelly spent a day collecting data by sitting in the chair and recording her observations about how many hummingbirds came to each feeder, how long they stayed at each, and, when possible, if they returned to a feeder after tasting another. Shelly's experiment will not give conclusive results. What is the most important reason why it will not?

The feeders are different colors

In the 19th century, scientists knew that light was some kind of wave. And every kind of wave science had yet described needed a medium to travel through—the way that sound waves travel through matter. But scientists had never observed light's medium. As they searched for evidence of it, scientists decided to call light's theoretical medium the luminiferous ether.

The results of the Michelson-Morley experiment did not fit the theory of the luminiferous ether, so the theory had to be rejected.

What do the following areas of scientific understanding have in common? the understanding of the structure of the Solar System the understanding of how traits are passed from parents to offspring the understanding of the building blocks of matter and life

The scientific knowledge related to these areas has changed over time.

How do the test variables (independent variables) and outcome variables (dependent variables) in an experiment compare?

The test variable (independent variable) controls the outcome variable (dependent variable)

A beaker containing 50 mL of water is being heated from 20ºC to 50ºC, and during the heating time the rising temperature is recorded every two minutes. Which table is best suited for recording the data?

Time Temp 0 2 4 6 8 10

Shawn is planning a scientific experiment. He wants to learn whether time of day has an effect on how far the roses in his mother's garden are open. He plans to measure the diameter of each flower on three rosebushes every hour during a week in the spring. What is the test variable (independent variable) in Shawn's experiment?

Time of day

Spontaneous generation is the idea that a living thing can arise from nonliving material. This idea was a prevailing theory up until the late 1700s. What most likely caused this theory to be discarded?

a series of experiments showed that living things only arise when other living things reproduce

In a controlled scientific experiment, a scientist

alters the test variable (independent variable) and observes the effects on the outcome variable (dependent variable)

Kimberly wants to build a computer model of her local climate. What sort of data should Kimberly collect in order to create her model?

average monthly temperatures and precipitation levels for the last 10 years

Nick is conducting a controlled experiment to test whether music helps daisies grow faster. Below are the steps to Nick's experiment: 1. Plant daisies in two separate flowerpots. 2. Place flowerpot 1 in a green room with music. 3. Place flowerpot 2 in a similar green room without music. 4. Give the daisies the same amount of food and water each week. 5. Measure the growth of the daisies. 6. Draw conclusions based on the data collected. Which group is the control group in Nick's experiment?

flowerpot 2

Scientific knowledge can withstand the test of time because

it is open to change as new evidence or data is discovered.

A biologist wants to demonstrate how atoms are combined in a DNA molecule, a geologist wants to demonstrate how mountains are formed as a result of tectonic plate collisions, and a physicist wants to demonstrate wave motion. What method would best allow these three different scientists to demonstrate their concepts?

model-making

In a controlled scientific experiment,

one or more variables are kept constant.

Lexi is researching crime rates. She is trying to make a conclusion about whether the crime rate changes with the population in each county in her state. What is the outcome variable (dependent variable) of her investigation?

the crime rate

Shakita wants to know if the pH of an open can of soda changes over time. To test this, she designs an experiment that will involve the following steps. Open a can of soda and measure the pH. Allow the open soda can to rest undisturbed on a level countertop at room temperature. Measure the pH of the open soda can every day at the same time for ten consecutive days. What is the outcome variable (dependent variable) in Shakita's experiment?

the pH of the soda

Darren performed an experiment in which he measured the amount of force that was required to accelerate an object at a rate of 5 m/s2. Then, he repeated his experiment four more times and calculated the average force that was needed. Why did Darren repeat his experiment?

to increase the reliability of his data