1. Chapter 1
The Science of Biology

2. Science as a Way of Knowing
Science is an organized way of gathering and analyzing evidence about the natural world.
One goal of science is to provide natural explanations for events in the natural world. Science also aims to use those explanations to understand patterns in nature and to make useful predictions about natural events.

3. The Scientific Method Scientific methodology involves:
observing and asking questions,
making inferences and forming hypotheses,
conducting controlled experiments,
collecting and analyzing data,
and drawing conclusions.

4. Observing and Asking Questions
Scientific investigations begin with observation, the act of noticing and describing events or processes in a careful, orderly way.
For example, researchers observed that marsh grass grows taller in some places than others. This observation led to a question: Why do marsh grasses grow to different heights in different places?

5. Inferring and Forming a Hypothesis
After posing questions, scientists use further observations to make inferences, or logical interpretations based on what is already known.
Inference can lead to a hypothesis, or a scientific explanation for a set of observations that can be tested in ways that support or reject it.

6. Inferring and Forming a Hypothesis
For example, researchers inferred that something limits grass growth in some places. Based on their knowledge of salt marshes, they hypothesized that marsh grass growth is limited by available nitrogen.

7. Designing Controlled Experiments
Testing a scientific hypothesis often involves designing an experiment that keeps track of various factors that can change, or variables. Examples of variables include temperature, light, time, and availability of nutrients.
Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed. All other variables should be kept unchanged, or controlled. This type of experiment is called a controlled experiment.

8. Controlling Variables
It is important to control variables because if several variables are changed in the experiment, researchers can’t easily tell which variable is responsible for any results they observe.
The variable that is deliberately changed is called the independent variable (also called the manipulated variable). On a graph this variable will always be placed on the X axis.
The variable that is observed and that changes in response to the independent variable is called the dependent variable (also what's being measured). On a graph this variable will always be placed on the Y axis.

9. Control and Experimental Groups
Control Group- the group in the experiment not receiving the independent variable.
Experimental group- Gets all the same conditions of the control group but in addition also receives the independent variable.

10. Collecting and Analyzing Data
Scientists record experimental observations, gathering information called data. There are two main types of data: quantitative data and qualitative data.
Quantitative data are numbers obtained by counting or measuring. In the marsh grass experiment, it could include the number of plants per plot, plant sizes, and growth rates.
Qualitative data are descriptive and involve characteristics that cannot usually be counted. In the marsh grass experiment, it might include notes about foreign objects in the plots, or whether the grass was growing upright or sideways.

11. Drawing Conclusions
Scientists use experimental data as evidence to support, refute, or revise the hypothesis being tested, and to draw a valid conclusion.
New data may indicate that the researchers have the right general idea but are wrong about a few particulars. In that case, the original hypothesis is reevaluated and revised; new predictions are made, and new experiments are designed.
Hypotheses may have to be revised and experiments redone several times before a final hypothesis is supported and conclusions can be drawn.

12. Scientific Attitudes
Good scientists share scientific attitudes, or habits of mind, that lead them to exploration and discovery.
Curiosity
Good scientists are skeptics, which means that they question existing ideas and hypotheses, and they refuse to accept explanations without evidence.
Scientists must remain open-minded, meaning that they are willing to accept different ideas that may not agree with their hypothesis.
Researchers need to think creatively to design experiments that yield accurate data.

13. The Role of Technology
Discoveries in one field of science may lead to new technologies, which enable scientists in other fields to ask new questions or to gather data in new ways.
Technological advances can also have big impacts on daily life. In the field of genetics and biotechnology, for instance, it is now possible to mass-produce complex substances—such as vitamins, antibiotics, and hormones—that before were only available naturally.

14. Scientific Theories
In science, the word theory applies to a well-tested explanation that unifies a broad range of observations and hypotheses and that enables scientists to make accurate predictions about new situations.
Scientific Law: This is a statement of fact meant to describe, in concise terms, an action or set of actions. It is generally accepted to be true and universal, and can sometimes be expressed in terms of a single mathematical equation.

15. Science, Ethics, and Morality
When scientists explain “why” something happens, their explanation involves only natural phenomena. Pure science does not include ethical or moral viewpoints.
For example, biologists try to explain in scientific terms what life is and how it operates, but science cannot answer questions about why life exists or what the meaning of life is.
Similarly, science can tell us how technology and scientific knowledge can be applied but not whether it should be applied in particular ways.

16. Living things
-organisms, a living thing that posses the traits of life.
What is a trait?
A trait is a specific feature of something. Hair color, eye color, height

17. How to distinguish a living thing from a non living thing.
If something expresses one of traits of life it is considered to be alive. The traits of life are:
Response
Movement
Organization
Reproduction
Growth and development

18. Traits of Life
Response- organisms have the ability to react to their environments.
- A stimulus is a signal to which an organism responds.
Ex: When an animal runs away from a loud noise. Or when a plant grows in the direction of sunlight. (external responses)
When you run your body temperature rises so your body sweats to cool you down. (internal response)
-This is an example of Homeostasis, the maintaining of a proper internal condition.
● What is an environment and what is included in an organisms environment?
- An environment includes everything in its surroundings. It includes other organisms, water, weather, temperature, soil, sound and light.

19. Traits of Life (continued)
2) Movement- all organisms show some form of movement which requires the use of energy.
Humans and animals- run, walk, fly
Plants- they grow out in the direction of sunlight and water.
Bacteria and Algae- use things called flagella and pseudo pods for movement.

20. Traits of Life (continued)
3) Organization- All living things are made up of parts that are organized.
Living things are based on a universal genetic code.
All organisms store the complex information they need to live, grow, and reproduce in a genetic code written in a molecule called DNA.
All organisms are made of cells, the smallest unit of living things.
Some organisms only contain one cell. (bacteria)
&
- Some organisms contain many cells. (Plants and animals)

21. Traits of Life (continued)
4) Reproduction- All living things reproduce, meaning they make more of their own kind.
Two types of reproduction:
A) Sexual reproduction- Here two parents are needed, a male and female, to create one of their own kind. (Animals)
B) Asexual reproduction- Here only one parent is needed to reproduce itself. (bacteria)

22. Traits of Life (continued)
5) Growth and development- All organisms express changes that take place over the course of their lives, this is known as development. -
-Living things obtain and use material and energy to grow, develop, and reproduce.
-The combination of chemical reactions through which an organism builds up or breaks down materials is called metabolism.

23. Matter and Energy
Life requires matter that serves as nutrients to build body structures, and energy that fuels life’s processes.
Some organisms, such as plants, obtain energy from sunlight and take up nutrients from air, water, and soil.
Other organisms, including most animals, eat plants or other animals to obtain both nutrients and energy.
The need for matter and energy link all living things on Earth in a web of interdependent relationships.

24. Types of Science
Many different types of science exist. And they are all named based on the subject matter they are studying.
-Ex:
Biology= the study of life
Earth Science = study of Earth and Space
Chemistry= the study of the composition and structure of matter.
Biochemistry= study of chemical composition of biological forms.
Physics= study of the interactions between matter and energy

25. Scientific Measurement: Common Metric Units