Biology Chapter 1-1 and 1-2

Today you will learn about: Observations Inferences The scientific process –Hypothesis –Controlled experiment Variables in experiments –Theory

Define the following terms. Science –organized way of using evidence to learn about the natural world; also, the body of knowledge that scientists have built up after years of using this process Observation –use of one or more of the senses—sight, hearing, touch, smell, and sometimes taste—to gather information Data –evidence; information gathered from observations Inference –logical interpretation based on prior knowledge and experience Hypothesis –possible explanation, based on research, for a set of observations or possible answer to a scientific question. It must be a testable.

What are two types of Observations? Qualitative observations –involve characteristics that cannot be easily measured or counted, such as color or texture. Quantitative observations –involve numbers, for example, counting or measuring objects.

Take a minute to write 2 qualitative observations and 2 quantitative observations. Make an inference based on your observations.

Making Inferences

Scientific Method Observation State the problem what question would you like to answer? Hypothesis –An explanation based on research that can be tested Controlled Experiment –An experiment set up to test the hypothesis created. Only one variable should be tested at a time. Record and analyze data – Qualitative and quantitative date…Using graphs, diagrams, computers Conclusion –Draw a conclusion based on the data collected. Was your hypothesis correct? If so, how can you test it further. Publishing and Repeating Investigations –The results of the experiment should be published for other scientists to test.

A Controlled Experiment 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. What are the two variables in a controlled experiment? Independent /manipulated Variable –Is the variable which is deliberately changed Dependent/responding Variable –Is the variable which changes in response to the manipulated variable

Bio 1-2 and 1-3 Today you will learn: 1.The scientific process: “Spontaneous Generation” 2.Characteristics of Living Things 3.Levels of Organization

Spontaneous Generation hypothesis () stating that life could arise from nonliving matter

Francesco Redi (1668)

Anton van Leeuwenhoek 1670’s Invented the first microscope. Found “animalcules” we know as Microorganisms

John Needham mid 1700’s Hypothesis –Spontaneous Generation is true Experiment –Boiled gravy in a flask and observed Data –Microorganisms appear after cooling Conclusion –Spontaneous Generation is True

Lazzarro Spallanzani Late 1700’s Hypothesis – spont. gen. is not true. Experiment – two flasks one sealed after boiling Data and conclusion – only unsealed jar had living organisms. Spont. Gen. Not true What is the problem with his experiment?

Louis Pasteur (1864) After Xavier was established Pasteur put the idea of Spontaneous Generation to rest.

How a theory develops. In science, the word theory applies to a well-tested explanation that unifies a broad range of observations.

When Experiments are not Possible

Section 1-3 Characteristics of Living Things And Levels of Organization

8 Characteristics of Living Things 1.Living things are made up of units called cells.

2. Living things reproduce. Sexual Reproduction Asexual Reproduction

3. Living things are based on a universal genetic code.

4. Living things grow and develop.

5. Living things obtain and use materials and energy.

6. Living things respond to their environment.

7. Living things maintain a stable internal environment. Homeostasis –process by which organisms maintain a relatively stable internal environment

8. Taken as a group, living things change over time.

Levels of Organization

Quiz 1 1. Why is Redi’s experiment on spontaneous generation considered a controlled experiment? 2. Explain the hypothesis of spontaneous generation. 5. What problem might arise if a researcher fails to control the relevant variables in an experiment?

Biology Chapter 1-1 and 1-2 Homework Biology textbook Read pgs. 16 – 22 Complete section 1-2 in G.R soft-cover book

Homework Biology Textbook Read Sections 1-3 and 1-4 pages and 24-28