Name ______
Date ______
Biology
Chapter 1 NTWS
SECTION 1
What is Science?
•______- is an organized way of using evidence to learn about the natural world.
•The goal of science is to investigate and understand the ______, to explain events in the natural world, and to use those explanations to make useful ______.
Thinking Like a Scientist
•______- The process of gathering information about events or processes in a careful, orderly way. (Usually involves the senses, particularly sight and hearing.)
•______- Information gathered from observations.
–Quantitative - Expressed as numbers
–Qualitative - Expressed as characteristics
•______- A logical interpretation based on prior knowledge or experiences.
Explaining and Interpreting the Evidence
•After the initial observation, scientists must research the ______they collected by any means necessary. (Computer, Library, Newspaper, Journals, Personal Interview)
•______- A proposed scientific explanation for a set of observations
–Often referred to as an “______”
–Only useful if it can be ______
–Scientists generate hypotheses using ______, (what they already know); logical ______; and informed, creative ______.
Science is a Way of Knowing
•Science is a ______process.
•New tools, techniques, and discoveries can lead to new scientific understandings.
SECTION 2
How Scientists Work
•For thousands of years, people have noticed that living things have magically appeared from non-living things.
–Maggots appear on dead animals or rotting meat.
–Mice appear on piles of grain.
–Beatles appear on cow dung.
- Scholars from that era called this phenomenon ______.
Designing an Experiment
•The maggot theory lasted until 1668 when an Italian physician, Francesco ______designed an experiment to test his hypothesis.
•Redi believed that maggots were the ______form of house flies. To test this hypothesis, Redi designed the following experiment.
A Controlled Experiment
•Whenever possible, a hypothesis should be ______by an______in which only one variable is changed at a time. All other variables should be kept unchanged, or controlled.
•This is called a ______.
•______ (Manipulated Variable) - the variable that is deliberately changed (Gauze).
•______(Responding Variable) - the variable that is observed (Maggots appear).
Recording and Analyzing Results
•Scientists must keep written ______of their observations, or data, that occur during their experiment.
•In the past, most results were written in ______or ______. They also could have drawn pictures like the following.
•Today, records can be kept with ______, ______, and other electronic devices.
Drawing a Conclusion
•Scientists use the data from an experiment to evaluate the hypothesis and draw a valid ______.
•Was the hypothesis supported or not supported by the results?
Repeating Investigations
•Many times after a scientist publishes their work, other scientist will______their ideas.
•In the mid 1700’s, an English scientist named John ______tested Redi’s ideas using another organism called “animalcules” (Discovered by Anton van Leeuwenhoek).
•Needham believed spontaneous generation could occur under the right conditions.
•He sealed a bottle containing gravy and heated to kill any living thing.
•Several days later, he examined the bottle and saw it was filled with activity.
•He inferred “these little animals can only have come from the gravy.”
Spallanzani’s Test
•Lazzaro______read Redi and Needham’s work. He believed Needham did not heat the gravy enough and decided to do the following experiment.
Pasteur’s Test
•Another scientist named Louis ______wanted to disprove spontaneous generation. He stated that Spallanzani’s experiment wasn’t valid because living things need air to survive. The sealed bottle of gravy prevented that.
•Pasteur used a ______that had a ______which allowed air in but kept microorganisms out.
SECTION 3
Characteristics of living Things
•Living things…
- Are made up of units called ______
- ______
- Are based on a universal ______
- ______and______
- Obtain and use ______and ______
- ______to their environment
- Maintain a stable internal environment (______)
- ______over time
•______– are the smallest unit of an organism that can be considered alive.
•______– Living things made up of only one cell
•______– Living things that are made up of more than one cell
•______ - Involves the joining of two cells from two parents.
•______ - Involves only one parent
- ______
- Budding
•Biologists know the directions of inheritance are carried by a molecule called ______ (Deoxyribonucleic Acid).
•One fertilized egg cell divides over over again until a mature organism is formed. As these cells divide, they change shape and structure to form cells such as liver, brain, or muscle cells. This is called ______.
•______– combination of chemical reactions through which an organism builds up or breaks down materials as it caries out its life processes.
•______– signal to which an organism responds
•______– process by which organisms maintain a relatively stable internal environment
•______– change in a kind of organism over time
SECTION 4
Tools and Procedures
A Common Measurement System
•Most scientists use the ______when collecting data and performing experiments.
•Metric system – decimal system of measurement based on certain physical standards and on multiples of ______
Microscopes
•______– produce magnified images by focusing visible light rays
–______light microscope – uses two lenses to form an image
•______– produce magnified images by focusing beams of electrons
–______microscope (TEM) – shines a beam of electrons through a soecimen
–______microscope(SEM) – scan a narrow beam of electrons back and forth across the surface of the specimen