Introduction to Science and Biology

What is science? A way of observing, a way of thinking, and

a way of knowing about the world. Science is a process not a thing.

Science rarely proves anything, but aims for the best understanding to make useful predictions.

SCIENCE MUST BE…..TESTABLEREPEATABLE

Which of the following questions could be answered by science?

1. Is an elephant beautiful?

2. Is it ethical to test beauty products on animals?

3. How does smoking damage your lungs?

4. Do people watch too much TV?

Scientific Methodology

General Stages of Scientific Investigation1. Asking a Question

2. Collecting Information/Making observations

3. Inferring and forming a hypothesis

4. Designing a controlled experiment to test the hypothesis

5. Collecting/Analyzing Data (qualitative vs. quantitative)

6. Drawing Conclusions

If the hypothesis is supported scientists will retest the hypothesis.

If the hypothesis is not supported scientists will modify or form a new hypothesis.

How do we make a valid hypothesis? Inference and imagination can lead to a

hypothesis.

If..then format Example:

If marsh grass has abundant nitrogen in the soil, then it will grow taller than marsh grass without nitrogen in the soil.

Variables and Controls Variables – factors that change

Independent – you manipulate (what you deliberately change)

Dependent – change in response to the independent variable (variable that is measured)

Control Group – used for comparison Nothing is changed

Practice Problem You recently planted a pot of daisies, but

they are becoming wilted and seem to be dying. You would like to find out what is happening, and what you can do to save your flowers.1. What is the question you are trying to answer?

2. What would your hypothesis be?

3. Design a controlled experiment to test this hypothesis.

Review Question: Krusty was told that a certain itching

powder was the newest best thing on the market, it claims to cause 50% longer lasting itches. He buys the itching powder and compares it to his usual product. One test subject (A) is sprinkled with the original itching powder, and another test subject (B) was sprinkled with the experimental itching powder. Subject A reported having itches for 30 minutes. Subject B reported to have itches for 45 minutes.

1. What is Krysty’s hypothesis?2. What was Krusty’s control group?3. The variables in this experiment are the type

of itching powder and the itches experienced by subjects. Which is the independent and which is the dependent variable?

4. Does the Krusty’s data support his hypothesis?

Review Question cont.• Lisa is working on a science project. Her task is

to answer the question: "Does Rogooti (which is a commercial hair product) affect the speed of hair growth". Her family is willing to volunteer for the experiment. Bart uses Rogooti, while Maggie uses no hair product. After 1 week Bart’s hair has grown 2cm and Maggie’s hair has grown 0.5cm.

1. What could Lisa’s hypothesis be?2. Who is Lisa’s control group?3. Which is the independent variable and which is the

dependent variable?4. Was Lisa’s hypothesis supported or rejected?

Data In science we measure using metric units

Review Question Why do scientists need a common system

of measurement?

SI conversions practice1. 1m = _____cm

2. 2500mL = _____L

3. _____s = 5400ms

4. 0.017g = _____mg

Draw a line graph to display the data below:

Time (Days) Height of flower (cm)

0 0

1 0.5

2 1

3 2

4 2.5

You have performed an investigation to determine which of the thermostats in 3 different classes is most efficient.

To do this you timed how long it took each room to reach a stable temperature. You started the time when you turned on the heat and recorded the temperature every 5 minutes for 25 minutes.

Use the data below to construct a line graph showing each room on the same graph.

Time (min)

Classroom A Temperature (ºC)

Classroom B Temperature (ºC)

Classroom C Temperature (ºC)

0 16 16 16

5 17 17 17

10 19 20 17.5

15 20 23.5 18

20 21 25 18.5

25 20.5 26 18

Scientific Attitudes Good scientists share scientific attitudes, or habits of mind, that lead them to exploration and discovery.

• Curiosity• skepticism • open-mindedness • creativity.

Communicating Results

• Peer review• Look for bias, oversights, or mistakes• Ensures highest standards are met

• Publish articles after peer review

• These communications spark new questions.

What is a scientific theory? A theory unites and explains a broad range of

observations. A theory is a well-supported scientific

explanation that makes useful predictions.

No Theory is considered the absolute truth The possibility always remains that future

evidence will be uncovered and cause a scientific theory to be revised or rejected.

Science and Society• Scientific questions involve the society in which

we live, our economy, and our laws and moral principles.

• Pure science does not include ethical or moral viewpoints.

• 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.

What is biology? The study of life Bio – life logy – study of

Patterns that connect all forms of life: Composed of one or more cell. Reproduce – sexual vs asexual Able to obtain and use energy

Metabolism Maintain a stable internal environment

Homeostasis Universal genetic code

DNA Evolve Grow and develop

Biology in Your World Biologists are constantly working to solve

life’s problems: Preserving our environment Improving the food supply Understanding the human genome Fighting diseases