Question

chapter 1: scientific inquiry and biology
plants, and how cells divide to make plants grow. any new findings that scientists obtain from their experiments are shared with other scientists. for hundreds of years, this has been done through the publication of research reports. these reports are printed in scientific journals and sent around the world. now, scientific findings are posted on the internet as well, to be read by other researchers who work on similar topics. experimental results are considered valid if other scientists can obtain the same results when they repeat the experiment under the same conditions.
it is through this community of scientific study that explanations about how the world works are constantly revised and expanded. as scientists study each others work, new ideas develop. a conclusion that is based upon the results of an experiment is called an inference. in the plant investigation, the conclusion that light changes the growth of a plant stem is an example of an inference. in scientific inquiry, an inference always needs to be tested again (by conducting more experiments) to be confirmed. one way to do this is to make a new prediction from the inference. if the new prediction is tested and turns out to be true, it is strong evidence that the inference was valid. for example, based on the inference that light affects the growth of plant stems (causing them to bend), the prediction might be made that only plants with soft green stems can bend, whereas plants with hard wooden stems cannot. this would require a new experiment.
the study of science never ends because each new answer to a research problem leads to another question. this is scientific inquiry—the ongoing process of learning about the world around us.
chapter 1 review
part a—multiple choice

1. dr. jones met a man who had been bitten by venomous snakes several times over many years, yet he was not sick. the doctor thinks that something produced in the mans blood protects him from harmful effects of the poison. this idea, or possible answer to a scientific question, is called a(n)

1 hypothesis
3 observation
2 inference
4 theory

1. a student placed slices of moist bread in a closed cupboard and noticed that mold grew faster on them than on slices of moist bread left out on a counter. the one difference in this experiment—the presence or absence of light—is called the

1 theory
3 dependent variable
2 hypothesis
4 independent variable

1. a logical explanation of natural phenomena that is supported by many scientific observations and experiments is called a(n)

1 hypothesis
3 factor
2 inference
4 theory

1. a student wants to test how much water is necessary to produce the most bread mold. she keeps one slice of bread dry while using varying amounts of water on other slices. the dry bread in this experiment is the

1 hypothesis
3 observation
2 control
4 theory

1. the number of organisms that are tested in an experiment is called the

1 variable size
3 sample size
2 controlled size
4 experimental factor

1. the scientific method is

1 a way of posing a research question only
2 used to organize data that is already known
3 an organized approach to problem solving
4 used by all scientists in an identical way

1. the best way to be sure that your experimental results are valid is to

1 ignore information from other sources
2 conduct your experiment one time only
3 use more than one variable in the experiment
4 test as large a sample size as possible

Explanation:

1. A hypothesis is a possible answer to a scientific question. Dr. Jones' idea about the man's blood - produced protection is a hypothesis.
2. The presence or absence of light is the variable being changed in the experiment, which is the independent variable.
3. A theory is a well - supported logical explanation of natural phenomena.
4. The dry bread slice is used as a control to compare with the slices with varying amounts of water.
5. The number of organisms tested in an experiment is the sample size.
6. The scientific method is an organized approach to problem - solving.
7. Testing a large sample size helps ensure experimental results are valid.

Answer:

1. 1. hypothesis
2. 4. independent variable
3. 4. theory
4. 2. control
5. 3. sample size
6. 3. an organized approach to problem - solving
7. 4. test as large a sample size as possible