The Scientific Method and Characteristics of Living Things

The Scientific Method and Characteristics of Living Things

What is Science? • Science is an organized way of using evidence to learn about the natural world. – Body of knowledge that scientist have built up over the years. 2

The Nature of Science • Scientific Methods- the variety of steps and tools scientists use to gather information and answer questions. 3

“The Scientific Method” • step by step process for experimentation. • Includes: Observationnoticing something that leads to a question. 4

Hypothesis • educated guess or explanation for the question • Ex: Fertilizer will cause plants to grow taller • Must be testable. 5

Experiment • Tests the hypothesis • Specific steps, procedure and materials • Includes 3 Variables 6

1. Controlled Variables- variables kept constant so they do not affect the results. 7

2. Independent Variable – Manipulated Variable – The variable (only 1) that is manipulated or changed to test its effect on the outcome • Ex: Fertilizer – X axis 8

3. Dependent Variable – Responding Variable – The variable that is measured or observed – Depends on changes made to the independent variable • Ex: Plant height, weight, number of flowers, etc. – Y axis 9

The data, charts and graphs resulting from the experiment are interpreted analyzed to form a… 10

Conclusion • A statement that supports or refutes the hypothesis • Ex: Fertilizer increases plant height. • Usually leads to more questions and a new hypothesis • All results must be verified and repeatable. 11

Scientific Theory An explanation of a natural phenomenon supported by a large body of scientific investigations and observations. Ex: The Cell Theory The Atomic Theory of Evolution 12

Practice 1. What are the dependent and independent variables? 13

What are the dependent and independent and controlled variables? 14

What are the dependent and independent variables? 15

Redi’s Experiment Redi animation 1. One jar was left uncovered. The second jar was covered 2. Maggots appeared only on the meat in the open jar. 3. Redi concluded that meat did not produce maggots-flies did. 16

Redi’s Variables –Controlled Variables- jars, type of meat, location, temperature, time –Independent Variable- Gauze covering that keeps flies away from meat - Dependent Variablewhether or not maggots appear 17

Redi’s Experiment • Disproved the widely accepted idea of Spontaneous Generation – living things come from nonliving things. • Used a control group- a standard to compare test results. In a control the independent variable is not present. 18

Observation: Frogs caught in polluted ponds have deformed limbs 19

Hypothesis: Data: Conclusion: youtube: The Scientific Method Made Easy 20

What Is Biology? Biology is the study of living things. Bio: life -ology: the study of 21

You tube: Intro to Char of Life What does it mean to be living? Define living vs. nonliving by 7 characteristics 1. All living things are complex, organized and made of cells 22

2. All living things get nutrients and energy from their environment 23

3. All living things regulate their internal environment so as to maintain a stable, constant condition-homeostasis 24

4. All living things grow and develop -increase in cell size or cell number 25

5. All living things respond to stimuli from their environment. youtube: jaws of death 26

6. All living things reproduce more of their own kind asexual reproduction…. . one parent produces …. . copies of itself sexual reproduction……………. . . two parents, each ……………. . . contributes to ……………production of ……………offspring based on universal code-DNA 27

7. All living things can adapt to their environment and evolvechange over time Adaptations are characteristics that allow organisms to survive and reproduce You Tube: Its Alive! You Tube: Char of Life