Chapter 1.5: Science Is Based on Quantitative Observations, Experiments, and Reasoning

Flashcards from Chapter 1.5 of Principles of Life, 3rd Edition.

Natural history

How organisms get their food, reproduce, behave, regulate their functions, and interact with other organisms; biologists use this to ask questions and form insights about nature

Quantification

Turning one’s observations into explicit counts or measures to be verified by others; our ability to do this has rapidly improved with new technologies and ideas

The hypothesis-prediction method

Includes 5 steps:

1. Making observations

2. Asking questions

3. Forming hypotheses or tentative answers

4. Making predictions based on the hypotheses

5. Testing the predictions by making additional experiments or observations

Hypotheses

Possible answers that are formed by scientists after doing research on a question

• To be included in good scientific practice, these must be testable, falsifiable, and repeatable

Data

Quantified measurements or observations from different groups

Controlled experiment

An experiment that deliberately changes, or manipulates, one or more of the factors being tested

• Requires groups that are as similar as possible, aiming to target the critical variable only

• Requires the creation of an experimental and control group, where variables are only manipulated in the experimental group for measurements

Comparative experiment

An experiment that compares unmanipulated data from different sources

• Relies on naturally occurring groups

Independent variable

In a controlled experiment, a variable manipulated independently of other considerations

Dependent variable

In a controlled experiment, a variable permitted to vary in ways depending on the independent variable

Null hypothesis

What many statistical tests start with; it is the premise that any observed differences are a result of chance

• Data is collected to calculate the probability this is correct to avoid making incorrect conclusions