Unit 1 Biology NotesCharacteristics of LifeObjective 1: List the six characteristics of life.

Objective 2: Use the six characteristics of life to determine if an object is living, non-living, or

dead.

Characteristics of Life

Characteristics of Life

All living things possess these characteristics at SOME time during their lifespan…

1.Growth and Development:• Living organisms grow and develop to a

mature adult form.– Growth is increase in size.– Development is change in shape/ability. 

Characteristics of Life

2.Reproduction:

• Living organisms have the ability to make more of their own kind and transmit genes and DNA from generation to generation.

Characteristics of Life

3.Adaptation to the Environment:

• A POPULATION of organisms is able to genetically adapt to changing environmental conditions (evolve over time).

Characteristics of Life

4. Cellular Organization:

• All living organisms are composed of one or more cells.

Characteristics of Life

5.Interaction with the Environment:

• Living organisms respond to stimuli in order to interact with the environment.

• This allows organisms to maintain HOMEOSTASIS (a stable internal environment).

Characteristics of Life

6. Energy Requirement:

• All living organisms use energy for their life processes.

Characteristics of Life

• G

• R

• A

• C

• I

• E

Growth and Development

Reproduction

Adaptation to the Environment

Cellular Organization

Interaction with the Environment

Energy Requirement

Objective 3: Describe unique characteristics of scientific study.

Objective 4: Describe the difference between a theory and a hypothesis.

Unit 1 Biology NotesThe Nature of Science

What is Science?

• Science:– An organized way of using evidence to learn

about the natural world.

Unique Characteristics of Science

Unique Characteristics of Science

• Deals with natural observable events, not supernatural

• Makes observations and collects measurable data.

Unique Characteristics of Science

• Data and observations are repeatable and capable of change.

• Leads to understanding and explanations that can be tested by examining experimental evidence.

Theory vs. Hypothesis• Hypothesis:

A possible explanation for a set of observations which guides further experimentation.

• Theory: An explanation for many related observations based on extensive scientific and experimental evidence in many conditions.

Objective 5: Write detailed observations in order to collect data.

Objective 6: Be able to distinguish between an inference and an observation.

Objective 7: Use observations to make appropriate inferences.

Unit 1 Biology NotesObservations and Inferences

Observations and InferencesObservation:

Def.: a statement about the characteristics of an object.• The characteristics are detected by the 5 senses.• The statement must be in a complete sentence.

Quantitative Observation: an observation that includes measurement or counting.

Qualitative Observation: an observation that does not include measurement or counting and therefore requires judgments. (description)

Inference: an assumption based on observations.

Objective 8: Write a testable hypothesis that predicts the relationship between the independent and dependent

variables.Objective 9: Identify and describe the components of

good experimental design from a sample investigation.Objective 10: Using the components of good experimental design, design and carry out an

experiment.Objective11: Construct a data table and an appropriate

graph to present data.

Unit 1 Biology NotesExperimental Design

Experimental DesignIndependent variable (IV):

What: the variable which is purposely changed or manipulated in an experimentWhy: it’s what you are testing

Dependent variable (DV): What: the variable which is measured and responds to the independent variableWhy: Measures what changes

Experimental DesignVariable Examples:1) Susie wants to know what temperature causes bacteria to

reproduce the fastest.What is the IV?

Temperature (of what??) Be specific!

What is the DV?Rate of bacteria reproduction or how fast bacteria reproduceHow to measure this? Be sure you can explain this.

2) Kevin wants to know if changing the amount of water will delay the leaves of a tree from dropping.

Experimental DesignHypothesis:

A possible explanation for a set of observations which guides further experimentation.

A hypothesis:• Must be testable• Predicts the relationship between one independent variable

(IV) and a measurable dependent variable (DV)• The direction of the IV/DV relationship must be included

in the hypothesis.

Experimental Design

• Example hypotheses1) If the amount of fertilizer increases, the plants

will grow.

2) If the amount of fertilizer changes, the plant will change.

3) Increasing the amount of fertilizer will cause an increase in plant height.

4) If the amount of fertilizer increases, the plants will taste worst.

Experimental DesignConstants:

What: variables which do not change during the course of the experimentWhy: so we know the results are due to changing the IV and not other factors

Control: What: the test group which does not receive the IV treatment, or a group that is chosen as the basis for comparison (the “normal” or “standard”)Why: to know what effect your IV has had on your experiment (sometimes you don’t need a control if you are only interested in comparing data sets)

Experimental Design

Repeated trials: What: an entire procedure is repeated to detect sources of procedural errorsWhy: account for procedural error

Multiple subjects: What: the use of many organisms in an experiment to account for range of variability in test organisms Why: account for variation in test subjects

Conclusion

A. Restate hypothesis and tell if data supports

B. Summarize data

C. Analyze data-trends/patterns/oddities

D. Summarize the relationship between the independent and dependent variables

Data TablesRemember to include the following:1. Specific Title

Why: Describes the content of the table, Describes the relationship between the IV and DV

2. Labels for IV and DVWhy: Clearly identifies all the data and results,

Organizes your columns and rows

Data TablesRemember to include the following:3. Units

Why: Shows the degree of measurement

4. AveragesWhy: Calculate and include these when appropriate (for example, when multiple subjects or repeated trials are used)

Data TablesRemember to include the following:

5. Organization and NeatnessWhy: Allows the reader to quickly understand the

data and gain information needed

• Hypothesis: Students who eat breakfast regularly will score higher on the ACT test. (The ACT test scores have no units)

Example Data Table

GraphsRemember to include the following:1. Specific Title

Why: Describes the relationship between the IV and DV

2. Label each axis Why: Clearly identifies all the data and results

GraphsRemember to include the following:3. Units

Why: Shows the degree of measurement

4. Appropriate type of graph: pie, bar, histogram, lineWhy: Depends on type of data and what you want to communicate

GraphsRemember to include the following:

5. Appropriate scale (do not use scale breaks!)

Why: Correctly depicts the data

6. Data Points stay within graph boundaries

Why: Correctly depicts the data

Type of Graphs• Pie Graph

– Show percent or part of a whole

Type of Graphs• Bar Graph

– Unrelated categories of data

–  Bars may go in any order

–  Bars may not touch

Type of Graphs• Histogram

– Related categories that share a value in the same range

– Example–  Bars touch

Type of Graphs• Line Graph

– Graphs continuous sets of data

–  Connect the points or do a line of best fit

–  Label lines or use a key