Chapter 1The Science of

Biology1-1: WHAT IS SCIENCE

What science is and is not…

KeyC#1: The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make useful predictions

Investigate

Explain

Make predictions

Three features of science:

1. In the context of the natural world

2. Data collection is organized (look for patterns/connections)

3. Must be testable by looking at evidence

Def: Science—an organized way of using evidence to learn about the natural world.

Thinking like a scientist

Scientific thinking: Def: Observation—use of

senses to gather information (data) in an orderly fashion

Data: Quantitative—expresses as

numbers (counting/measuring)

Qualitative—descriptive characteristics (cannot be counted)

What are some examples of quantitative vs. qualitative?

Scientists use data to make inferences.

Def: Inference—logical interpretation based on prior knowledge or experience (ex. water in reservoir)

Explaining and Interpreting Evidence

After initial observations of the natural world, researches will propose a Def: Hypothesis—proposed

scientific explanation for a set of observations

Hypotheses rise from: Prior knowledge

Logical inference

Informed, creative imagination

Must be testable. Can be ruled out or supported/confirmed.

Science as a way of knowing

The best scientists are skeptics

Don’t be afraid to ask questions.

Questions both existing and new hypotheses.

There are limits to science and definite lines that should not be crossed. What do you think determines where these lines are drawn?

First question in the bible: Genesis 3:1

“Now the serpent was more crafty than any of the wild animals the LORD God had made. He said to the woman, ‘Did God really say, ‘You must not eat from any tree in the garden’?’”

Writing assignment: Where is the line? Write a paragraph (5 complete

sentences, TS, 3 SS, CS) explaining why Jenner’s research methods might have been controversial and whether you support/challenge his methods.

Edward Jenner video

Chapter 1The Science of

Biology1-2: HOW SCIENTISTS WORK

Designing an experiment First: Ask a question. (i.e. how did

maggots get on the meat? Spontaneous generation?) Def: Spontaneous generation: life

from non-living matter

Second: Form a hypothesis. (i.e. maybe maggots come from flies) Remember: observe and propose

an explanation

Setting up a controlled experiment

Variables: factors that can change (i.e. equipment used, materials, temperature, light, time)

KeyC#1: Whenever possible, a hypothesis should be tested by an experiment in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.

Controlled experiment:

Manipulated variable: changed by the researcher

Responding variable: changes in response to the manipulated variable

Let’s look at Figure 1.8 (Pg. 9)

Designing an experiment cont’d…

Recording & Analyzing Results:

Always keep a record of your data (hard copy/digital)

What types of data can we observe?

Drawing a conclusion:

Data is used to refute for support the hypothesis.

Remember: have integrity! Do not manipulate your data!

Repeating experiments:

Your work is a contribution to the science community

Let’s look at Figure 1-11, pg. 12

How did Pasteur’s test add to Redi’s experiment? What was his conclusion?

When experiments are not possible

Other ways of testing a hypothesis: Field studies

Clinical studies (i.e. cancer-causing chemical)

How a theory develops: Well supported hypothesis

can become a theory

Def: Theory—well tested explanation that unifies a broad range of observations

Remember: a theory cannot be considered as absolute truth. Why?

Chapter 1The Science of

Biology1-3: STUDYING LIFE

Characteristics of living things Def: Biology—The science that

employs the scientific method to study living things

KeyC#1: Living things share the following characteristics…

1. Made up of units called cells

2. Reproduce

3. Based on a universal genetic code

4. Grow and develop

5. Obtains and use materials and energy

6. Respond to their environment

7. Maintain a stable internal environment

8. Change over time

Big Ideas in Biology: Timeline of our learning…

Science as a way of knowing

Interdependence in nature

Matter and energy

Cellular basis of life

Information and Heredity

Unity and diversity of life

Evolution

Structure and Function

Homeostasis

Science, Technology, and Society

What idea are you most excited about learning?

Branches of Biology

KeyC#2: Some of the levels at which life can be studied include:

Molecules

Cells

Groups of cells

Organisms

Populations

Communities

Ecosystems

Biosphere

Complete your flowchart! Hole punch and keep in your handouts divider!

Biology is a part of your every day life! (p. 22)

Chapter 1The Science of

Biology1-4: TOOLS AND PROCEDURES

A Common Measurement System

KeyC#1: Most scientists use the metric system when collecting data and performing experiments.

Metric System

Decimal system

Based on physical standards

Scaled on multiples of 10

Let’s look at figure 1-21 (p. 24)

How do scientists collect data??

What is the purpose of a graph or table?

Microscopes

Microscopes—devices that produce magnified images of structures that are too small to see with the unaided eye

KeyC#1: Light microscopes produce magnified images by focusing visible light rays. Electron microscopes produce magnified images by focusing beams of electrons.

Read Appendix D!

Light Microscopes:

View living things 1000x magnified

Electron Microscopes:

View smaller non-living or dead samples with more detail than light micro.

TEM: inside of cells

SEM: surface of cells

Laboratory Techniques

Cell culturing: growing a single cell into many cells (cell culture)

Cell fractionation: separate cell parts (blend & centrifuge)