Scientific Method
the kind of soil in which the seeds are planted
In the 300s BCE, a Greek philosopher proposed that life can spring from nonliving things. Frogs were born of mud, this philosopher proposed. In the 1500s, scientists tried to prove that rotting meat spontaneously produced flies.
A piece of meat left on a counter for several days will seemingly produce maggots, which then pupate into flies. In 1668, Francesco Redi challenged this idea by placing meat in sealed containers next to unsealed containers. The sealed container did not contain any flies, while the unsealed container did. Francesco Redi concluded that life can spring only from life.
What best describes why this is considered good science?
Science revises previously made statements when new evidence is discovered.
Evolutionary theory has become the central organizing principle of biological science. Could this scientific theory ever become a scientific law?
No
There are more species of insects than any other species on Earth combined, so insects must have particular advantages that allow them to populate many different environments. This statement is an example of
An Inference
Which of these is not one of the basic characteristics of all living organisms?
Homeostasis
Cellular Organization
Sexual Reproduction
Energy Utilization
Sexual Reproduction
The tested factor that can affect the outcome of a controlled experiment is called the...
Independent Variable
After a team of scientists completes an investigation, they submit an article about the investigation to a scientific journal. Before the journal publishes the article, they send it to other scientists for an anonymous, independent review. What is the purpose of this review?
to evaluate the methods and test the results of the investigation
How is the word theory used in science?
Scientists use the word theory when it applies to a tested, highly reliable scientific explanation of events in the natural world.
Jane Goodall spent years with the chimpanzees of Gombe. Sitting quietly for hours, she watched the animals closely and took notes about their behavior.
What was Jane Goodall doing?
Making Observations
A student noticed a fuzzy dark spot on the classroom floor that was not there last week. He takes a sample of the spot and examines it under the classroom microscope and continues to observe the spot on the floor for the next 5 days. He adds the following qualitative data to his lab notebook:
What inference can the student make from these observations?
The spot is living.
Testing hypotheses often involves designing experiments. Which of the following is the factor that is observed and measured in an experiment?
A griffin is a mythical creature that appears in many stories. It has the head of an eagle and the body of a lion. What role, if any, could the griffin have in the science of biology?
The griffin has no role in biology, because it is not real.
In biology, a scientific theory _________ a phenomenon, while a scientific law _________ a
phenomenon.
explains, describes
In the metric system, what do the kilogram, kilometer, and kilocalorie have in common?
All are units 1000 times larger than a base unit.
Scientists share findings with other scientists by publishing their hypotheses, experimental methods, results, and analyses in peer-reviewed scientific journals. What is the importance of this step in scientific investigations?
It allows researchers to share ideas and certifies that the work meets standards of the scientific community.
A student conducted an original, well-designed experiment, carefully following proper scientific procedure. In order for the conclusions to become generally accepted, the experiment must
be repeated to verify the reliability of the data
Which of the following is an example of a scientific question?
Does adding sugar to water keep flowers fresh?
Which flowers are prettier, daisies or roses?
Do cats make better pets than dogs?
Are friendly people on time more often than unfriendly people?
Does adding sugar to water keep flowers fresh?
Michael’s grandmother is taking part in an experiment to determine how well a new headache medication works. In this experiment, the people in Group A are taking the new medication. The people in Group B, including Michael’s grandmother, are taking a pill that does not contain the new medication.
In this experiment, what is Group B?
Group B is the control
A scientist owns a company that is producing a new cancer drug, and the scientist is doing research. What helps to ensure that the scientist's work isn't biased in favor of his/her company?
publishing the research in a peer-reviewed journal.
Dr. Smith reads two research papers that present different conclusions about the same question. He knows the researcher who wrote Paper A, but does not know the authors of Paper B. When asked which paper he thinks has more merit, Dr. Smith replies, “Paper A.”
Because of Dr. Smith's connection to some of the researchers, he could be exhibiting
Bias
A student hypothesizes that plants require light to grow. She places 20 plants in a dark closet for 2 months and gives them equal amounts of water each week. After 2 months, all of the plants are dead. The student concludes that her hypothesis was correct. Why is her conclusion not valid?
She did not include a control group
Robert Hooke first discovered that bark from a cork tree was made of thousands of tiny
compartments he called cells. Later, Schleiden showed that all plants contained similar tiny
compartments, and shortly after this discovery, Schwann showed that all animals also
contained the same basic organization. Schwann used the term first created by Hooke, cells,
as the term for a new theory to explain the makeup of life, cellular theory.
What process is outlined in the paragraph above?
Scientific Consensus
In 1999, teams in Colorado and California were working together to put NASA’s Mars Climate Orbiter in orbit around Mars. The mission of the orbiter was to look for evidence of water. One team used English units of measurement. The other team used metric measurement. As a result, the spacecraft was lost. What would be the simplest and most cost-effective way to avoid mistakes like this in the future?
All personnel and missions should use the metric system
Camille notices that the leaves of her pothos plant are drooping this morning. The leaves were not droopy yesterday. She decides the plant needs to be watered. What had Camille just done?
made an inference based on past experience and observation
What is the main reason why scientific journals are the most reliable sources of science information?
They are peer reviewed.