1. Introduction to Biology

Scientific Method

A friend tells you that the theory of evolution is just an educated guess by biologists about how things work. Evaluate this statement.

Which of the following statements best distinguishes hypotheses from theories in science?
a. Theories are hypotheses that have been proved.
b. Hypotheses are guesses; theories are correct answers.
c. Hypotheses usually are relatively narrow in scope; theories have broad explanatory power.
d. Theories are proved true; hypotheses are often contradicted by experimental results.

Some stickleback fish develop protective spines, and other stickleback fish are spineless. Spine development is controlled by the expression of a gene known as Pitx1. The spineless phenotype is due to a mutation in Pitx1 that results in no expression of Pitx1 during development in regions where spines would otherwise form. When scientists compared the Pitx1 coding sequence in spined and spineless fish, they found this sequence was the same in both types of fish. Propose plausible hypotheses for the location of this mutation and for how it alters spine development.

A scientific hypothesis is                   .
a. an opinion;
b. a proposed explanation for an observation;
c. a fact;
d. easily proved true;
e. an idea proposed by a scientist

One hypothesis states that eating chicken noodle soup is an effective treatment for colds. Which of the following results does this hypothesis predict?
a. People who eat chicken noodle soup have shorter colds than do people who do not eat chicken noodle soup;
b. People who do not eat chicken noodle soup experience unusually long and severe colds;
c. Cold viruses cannot live in chicken noodle soup;
d. People who eat chicken noodle soup feel healthier than do people who do not eat chicken noodle soup;
e. Consuming chicken noodle soup causes people to sneeze

Cells are the basic structural & functional unit of life.

Which of the following statements about the cell theory is false?

Did You Know: The Scientific Method | Encyclopaedia Britannica

Nature of Science

 allows scientists to control all aspects of the system 

 No. It is impossible to control all aspects of a system; this is not what is meant by a "controlled experiment." 

 ensures that hypotheses can be confirmed with certainty 

 No. To confirm with certainty is the same as "to prove," and hypotheses cannot be proven. 

 ensures that the variable being tested is measured without error 

 No. Experimentation is important because hypotheses can be rejected when contradictory evidence emerges. All experiments are subject to error, which is why replication and reproduction of results are so important. 

Consider the process of scientific inquiry.

Experimentation is only one part of the process of scientific inquiry, but it is a very important step because it __________.

How is a scientific theory different from a scientific hypothesis?
a. It is based on weaker evidence;
b. It has not been proved true;
c. It is not falsifiable;
d. It can explain a large number of observations;
e. It must be proposed by a professional scientist

6 Steps to Formulate a STRONG Hypothesis | Scribbr 🎓

Scientific Method Example 1

If I perform a hypothesis test in which I demonstrate that the prediction I made in question 5 is true, I have                   .
a. proved the hypothesis;
b. supported the hypothesis;
c. not falsified the hypothesis;
d. B and C are correct;
e. A, B, and C are correct

Which of the following is an example of qualitative data?
a. The fish swam in a zigzag motion.
b. The contents of the stomach are mixed every 20 seconds.
c. The temperature decreased from 20°C to 15°C.
d. The six pairs of robins hatched an average of three chicks each.

Neil DeGrasse Tyson on why the scientific method is so important

 If all flying animals are birds, then it can be concluded that bats are birds. 

No. This is an example of deductive reasoning.

 Because worms lack bones, they are classified as invertebrates. 

 No. This statement is simply applying a definition to a group of organisms. 

 A paramecium moves by means of the rhythmic motion of its cilia. 

 No. Induction moves from a set of specific observations to reach a general conclusion. This statement is just one specific observation. 

 If the animals observed require organic molecules as nutrients, then it can be concluded that all animals require organic molecules as nutrients. 

Consider the process of inductive reasoning.

Which of the following statements most clearly demonstrates inductive reasoning?

Observation → Data Analysis → Hypothesis → Conclusion → Peer Review & Publish → Experiment.

Observation → Hypothesis → Experiment → Peer Review & Publish → Analysis → Conclusion.

Observation → Hypothesis → Experiment → Data Analysis → Conclusion → Peer Review & Publish.

Experiment → Hypothesis → Observation → Data Analysis → Conclusion → Peer Review & Publish.

Which of the following shows the best order of steps of the scientific method?

 Determining the physical causes for physical phenomena 

 No. This is within the realm of science. 

 Formulating testable hypotheses in seeking natural causes for natural phenomena 

Consider the process of scientific inquiry and limitations on the kinds of questions that can be answered.

Which of the following is outside the realm of scientific inquiry?

The Scientific Method

Scientific Method Basic Summary-Leaving Cert Biology (updated)

What features of the story on milk chocolate and heart health described in question 11 should cause you to consider the results less convincing?
a. The study was sponsored by a large milk chocolate manufacturer;
b. A total of 10 rats were used in the study;
c. The only difference between the rats was that human participants of the experimental group received chocolate along with their regular diets, and the human participants of the control group received no additional food;
d. The reporter notes that other studies indicate milk chocolate does not have a beneficial effect on heart health;
e. all of the above

In science, a theory is a(n)                   .
a. educated guess;
b. inference based on a lack of scientific evidence;
c. idea with little experimental support;
d. body of scientifically acceptable general principles;
e. statement of fact

Basic Theories of Biology

A scientist observes that even after sterilizing a broth, cells reappear in the broth over time. The scientist then asks: “Why do cells reappear in the broth after sterilization?” and designs/conducts an experiment. Considering this, appropriately label each of the following blanks as either a “prediction, hypothesis or theory.”________________: Cells will only appear in the broth exposed to a source of preexisting cells.________________: Cells appear only when preexisting cells grow &amp; divide; therefore, cells only appear in exposed broths.________________: All organisms consist of cells &amp; all cells come from preexisting cells.

Which of the following is an example of inductive reasoning?
a. All cows eat grass;
b. My cow eats grass and my neighbor’s cow eats grass; therefore, all cows probably eat grass;
c. If all cows eat grass, when I examine a random sample of all the cows in Minnesota, I will find that all of them eat grass;
d. Cows may or may not eat grass, depending on the type of farm where they live

A primary source of scientific results is                   .
a. the news media;
b. anecdotes from others;
c. articles in peer-reviewed journals;
d. the Internet;
e. all of the above

Introduction to Inductive and Deductive Reasoning | Don't Memorise

A story on your local news station reports that eating a 1-ounce square of milk chocolate each day reduces the risk of heart disease in rats and that this result is statistically significant. This means that                   .
a. people who eat milk chocolate are healthier than those who do not;
b. the difference between chocolate-eating and chocolate-abstaining rats in heart disease rates was greater than expected by chance;
c. rats like milk chocolate;
d. milk chocolate reduces the risk of heart disease;
e. two ounces of milk chocolate per day is likely to be even better for heart health than 1 ounce

Neil Degrasse Tyson - Analogy for the scientific method.

 a poorly supported idea that has little backing but might be correct 

 No. Consider how a theory differs from a hypothesis. 

 No. Then it would be called a hypothesis! 

 not correct unless it is several years old 

 No. This would be true only if the time allowed the accumulation of data that supported the hypothesis from which the theory arose. The mere passage of time does not turn a hypothesis into a theory. 

 a well-supported concept that has broad explanatory power 

Consider that there is much work involved in the synthesis of a theory.

A scientific theory is __________.

Predictions, Hypotheses, & Theories

 No. Making observations does not usually involve deductive reasoning. 

 No. The formulation of a hypothesis sets the stage for deductive testing. 

 In rephrasing an alternative hypothesis 

 No. Deductive reasoning is a form of logic that would allow you to predict an outcome. When does that happen in the scientific process? 

Consider the process of hypothesis-based scientific inquiry.

At which point in a study is a scientific investigator most likely to use deductive reasoning?

Which sentence best describes the logic of scientific inquiry?
a. If I generate a testable hypothesis, tests and observations will support it.
b. If my prediction is correct, it will lead to a testable hypothesis.
c. If my observations are accurate, they will support my hypothesis.
d. If my hypothesis is correct, I can expect certain test results.

 is not necessary if the scientist obtains enough background information 

 No. Background information does not tell whether the tested result will happen every time. 

 is too difficult for researchers doing fieldwork 

 No. No experimental result is considered correct, regardless of the conditions, if it is not shown to be repeatable. 

 should always be done by changing a variable 

 No. If a variable is changed, the experiment is not being repeated. 

 is necessary before concluding that a given set of results is correct 

Repetition of an experiment _________.

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