CHAPTER 1THE SCIENCE OF

BIOLOGY

1.1 WHAT IS SCIENCE?

• Science:

• An organized way of gathering and analyzing evidence about the natural world. • “Way of knowing”

WHAT ARE THE GOALS OF SCIENCE?

• Provide natural explanations for events in the natural world.

• Use data to make predictions.

• Examples• Gravity• Cell theory • Cure diseases

IS SCIENCE PERMANENT?

• No, science is constantly changing.

• With more research and future studies, we obtain new evidence.

• Science is always advancing.

SCIENTIFIC METHODOLOGY

• Involves observing, asking questions, making inferences and forming hypotheses, conducting controlled experiments, collecting and analyzing data, and drawing conclusions.

• Similar to the scientific method.

IS THIS A GOOD WAY TO THINK?

• http://www.youtube.com/watch?v=zrzMhU_4m-g

SCENARIO

• It’s late at night and you hear thunder and rain. Wind begins to pick up and you see a tree fall. Your power goes out. What do you reach for?• A. Flashlight

• The flash light does not work!

SCENARIO

• What is our observation?• Flashlight does not work.• What is our question?• What’s wrong with the flashlight?• What is our hypothesis?• The batteries are dead.

SCENARIO

• What is our prediction?• If the batteries are dead and we replace them,

the flashlight will work.• What is our test?• Replace the batteries.

SCIENTIFIC METHOD

• Observation:• Act of noticing and describing events or processes

in a careful, orderly way.

• Inference: • Logical interpretation based on what scientists

already know.

• What can you infer if you hear the doorbell?• Someone is at the door.

• Hypothesis:• Scientific explanation for a set of observations

that can be tested in ways that support or reject it.

• Controlled experiment:• When only one variable is tested. All other

variables should be kept unchanged or controlled.

• Is this a good experiment?• You plant grass seed on two different locations.

Location 1 is shaded, and you plant grass seed and water. Location 2 is not shaded, and you plant grass seed and fertilizer. • Why?

VARIABLES

• Independent variable:• The variable that is deliberately changed.

• Dependent variable:• The variable that is observed and that changes in

response to the independent variable.

CONTROL GROUPS

• Control group:• Exposed to the same conditions as the

experimental group except for one independent variable.

DATA

• Data- Recorded observations.

• Two types of data

• Quantitative

• Qualitative

• The higher the sample size the better!

QUANTITATIVE VS QUALITATIVE DATA

• Quantitative:• Collecting data with numbers.• Ex. Measurements.

• Qualitative: • Writing with descriptions instead of

measurements. Pictures and drawings.• Ex. Jane Goodall spent decades recording her

observations of chimpanzee behavior in the jungle.

QUANTITATIVE VS QUALITATIVE?

• 1. The lion woke up at sunrise everyday and cleaned his paws. This lion mated with the females lions.

• A. Qualitative

QUANTITATIVE VS QUALITATIVE?

• 2. • There were 7 ant hills in the grass.• The alligator grew 1 inch every week.

• A. Quantitative

1.2 SCIENCE IN CONTEXT

• What is this?

• Is this the most efficient way of writing a paper?

• What scientific attitudes help generate new ideas?

• Curiosity

• Skepticism

• Open-mindedness

• Creativity

• If I gave you a test right now, would you rather work alone or with a group?

• Why?

• In science, we practice peer reviewing. Scientists and students can collaborate and build on their ideas.

WHAT IS A SCIENTIFIC THEORY?

• What are some examples of theories?• Evolution• Gravity• Cell theory

• Theory:• A well tested explanation for a range of

phenomena.

• Theories can be changed over time. • Eventually turn into laws.

HOW DOES SCIENCE RELATE TO YOU?

• Health

• Diseases

• How are chemical wastes disposed?

• Should we keep relying on gasoline?

HOW OLD THE OLDEST LIVING PERSON?

• Born in 1898! • 117 years old !

• Would you want to know the exact health and characteristics of your baby?

• Science can do that, but is it ethical?

• Should we be able to determine and select certain traits for our kids?

SCIENCE, ETHICS, AND MORALITY

• Pure science does not include ethical or moral viewpoints. For example, biologists try to explain in scientific terms what life is, how life operates, and how life has changed over time.

• Science cannot answer questions about why life exists or what the meaning of life is.

• Must avoid bias• Bias: Particular preference or point of view that is

personal, rather than scientific.

1.3 STUDYING LIFE

• What is Biology? • Bio=• Life

• ology=• Study of

• Study of Life

• What is life? How do you define life?

• Biotic- • Living

• Abiotic-• Nonliving

• What are some examples?

CHARACTERISTICS OF LIVING THINGS

• Living things are made up of basic units called cells.

• Based on a universal genetic code.

• Obtain and use materials and energy.

• Grow and develop.

• Reproduce

• Respond to their environment

• Maintain a stable internal environment

• Change over time

• DNA:• Stores genetic information

• Stimulus:• Signal to which an organism responds

• Sexual reproduction:• Cells from two parents unite and form a new organism.• Ie. Most animals.

• Asexual reproduction:• Single organism produces offspring identical to itself. • Ie. Some plants, bacteria.

• What does your body do when it’s hot? When it’s cold?

• Homeostasis:• Keeping internal environment relatively stable.

• Metabolism:• Combination of chemical reactions through which

an organisms builds up or breaks down materials.

BIG IDEAS IN BIOLOGY CENTRAL THEMES

• Cellular basis of life

• Information and heredity

• Matter and energy

• Growth, Development, and Reproduction

• Homeostasis

• Evolution

• Structure and Function

• Unity and Diversity of Life

• Interdependence of Life

• Science as a Way of Knowing.

FIELDS OF BIOLOGY

• Biology includes many overlapping fields that use different tools to study life from the levels of molecules to the entire planet.

• Global Ecology:• Use satellites and supercomputers to study global

impacts.

• Biotechnology:• Analyze genetically modified rice plants.

• Paleontologists:• Study signs of ancient life. Roughly 1.8 million

living organisms.

• Molecular biology:• Analyzes a DNA sequence.

PERFORMING BIOLOGICAL INVESTIGATIONS

• Metric system:• Used for collecting data and performing

experiments.

SAFETY

•Follow safe practices

•https://www.youtube.com/watch?v=3PL4wUIFU-c•