Introduction to Biology, Characteristics of Life and ...acpssharepoint.appomattox.k12.va.us/.../SiteAssets/Unit_1/PPT_Intro...Introduction to Biology ! ... experimentation . Scientific

Introduction to Biology, Characteristics of Life

and Methods of Science

Introduction to Biology �  Biology—the science of life

�  Study the origins and history of life and once-living things

�  Study the structures of living things

�  Study how living things interact with one another �  Study how living things function

What do Biologists do? �  Study the diversity of life

�  Research disease

�  Develop technologies

�  Improve agriculture

�  Preserve the environment

Characteristics of Life �  1. Made of one or more cells

�  Living things are made of one or more cells �  Cells are the basic unit of structure and function in

all living things

�  2. Displays organization �  Living things also display organization, which means

they are arranged in an orderly way �  Specialized cells are organized into groups that work

together called tissues �  Tissues are organized into organs �  Organ are organized into organ systems that work

together to support an organism

�  3. Grows and develops �  Growth results in the addition of mass to an

organism and , in may organisms, the formation of new cells and new structures

�  4. Reproduces �  Reproduction is not essential for the survival of an

individual, but is not essential for the continuation of the species

�  A species is a group of organisms that can breed with one another and produce fertile offspring �  Asexual

�  Sexual

�  5. Responds to stimuli �  Anything that is part of the internal or external

environments and causes a reaction by the organism is called a stimulus

�  The reaction to a stimulus is a response �  What are some examples?

�  6. Requires energy �  Living things get their energy from food

�  Most plants and some unicellular organisms use light energy form the Sun to make their own food and fuel their activities (autotroph)

�  Organisms that cannot make their won food get energy by consuming other organisms (heterotroph)

�  7. Maintains homeostasis �  Regulation of an organism’s internal conditions to

maintain life is called homeostasis �  If anything happens within or to an organism that

affects its normal state, processes to restore the normal state begin

�  8. Adaptations evolve over time �  An adaptation is any inherited characteristic that

results from changes to a species over time �  Adaptations enable organisms to survive and pass on

their genes to the net generation

Nature of science �  What is science?

�  Science is a body of knowledge based on the study of nature

�  The nature, or essential characteristics, of science is scientific inquiry

�  Scientific inquiry is both a creative process and a process rooted in unbiased observations and experimentation

Scientific theory vs. scientific law �  A theory is an explanation of a natural

phenomenon supported by many observations and experiments over time (ex. Theory of evolution)

�  A scientific law describes relationships under certain conditions in nature, but does not explain why the relationship is the way it is (Mendel’s law of segregation)

�  The nature of science �  Makes observations and draws conclusions

�  Scientists choose subjects to study and decide what types of data to collect

�  They analyze the data collected to draw conclusions

�  The nature of science �  Expands knowledge

�  Most scientific fields are guided by research that results in a constant reevaluation of what is known

�  Pseudoscience imitates science, but do not provide science-based explanations

�  The nature of science �  Challenges accepted theories

�  Scientists welcome debate about one another’s ideas

�  Sciences advance by accommodating new information as it is discovered

�  The nature of science �  Questions results

�  Observations or data that are not consistent with current scientific understand are of interest to scientists

�  These inconsistencies often lead to further investigation

�  The nature of science �  Tests claims

�  Science-based information makes claims based on a large amount of data and observations obtained from unbiased investigations and carefully controlled experimentation

�  Conclusions are reached from the evidence

�  The nature of science �  Undergoes peer review

�  Before it is made public, science-based information is reviewed by scientists’ peers

�  Peer review is a process by which the procedures used during an experiment and the results are evaluated by other scientists who are in the same field or who are conducting similar research

�  The nature of science �  Science in everyday life

�  A person who is scientifically literate combines a basic understanding of science and its processes with reasoning and thinking skills

�  Ethical issues must be addressed by society based on the values it holds important

Methods of science �  Ask a question

�  Scientific inquiry begins with observations

�  Scientific inquiry involves asking questions and processing information from a variety of reliable resources

�  Methods of science �  Form a hypothesis

�  A hypothesis is a testable explanation of a situation (we no longer call this an educated guess!)

�  When a hypothesis is support by data from additional investigations, usually it is considered valid and is accepted by the scientific community

�  Extra credit: when doing a lab report and using the scientific methods, during your conclusion, do you support or reject your hypothesis? (Hint: research null hypothesis)

�  The methods of science �  Collect data

�  When a biologist conducts an experiment, he/she investigates a phenomenon in a controlled setting to test a hypothesis

�  The methods of science �  Controlled experiments

�  A control group in an experiment is a group used for comparison �  All variables remain the same with the exception of what

factor is being tested

�  The experimental group is the group exposed to the factor being tested

�  The method of science �  Experimental design

�  Independent variable—only one factor in a controlled experiment can change at a time �  This is the variable that the scientist can change.

�  Scientists change only one factor during an experiment. This allows the scientist to observe what changes have taken place and know that the changes are due to the one factor that was changed

�  Dependent variable—results from or depends on changes to the independent variable

�  The methods of science �  Data gathering

�  Data—information gained from observations

�  Quantitative data can be measurements of time, temperature, length, mass, area, volume, density, or other factors (hint: think numbers!)

�  Qualitative data are descriptions of what our senses detect (words; examples, colors, behaviors, patterns, types of food eaten, texture, smells, animal calls, etc.)

�  The methods of science �  Metric system

�  The metric system uses units with divisions that are powers of ten

�  SI units (International System of Units) are commonly used in science for consistency and ease of communication �  Using SI eliminates confusion among the science

community since all are using the same system of measurements

�  Common units

�  Meter – length

�  Liter – volume

�  Gram – mass

�  Second – time

�  Celsius – temperature (unless using Kelvin)

�  Methods of science �  Analyze the data

�  A graph of the data makes the pattern easier to visualize and grasp

�  Even when a hypothesis has not been supported, it is valuable

�  Pre-AP, you will need to graph data!

�  The methods of science �  Report conclusions

�  If the reviewers agree on the merit of the paper, then the paper is published for review by the public and use by other scientists

Review questions

�  Why is the metric system preferred by scientists?

�  Using the same system of measurements allows a scientist to repeat another’s work knowing that he/she is performing the experiments exactly the same

�  What is a testable explanation?

�  Observation

�  Hypothesis

�  Experiment

�  Constant

�  What is a testable explanation?

�  Observation

�  Hypothesis

�  Experiment

�  Constant

�  Which is not a characteristic of all organisms?

�  Made of one or more cells

�  Grows and develops

�  Capable of rational thought

�  Maintains homeostasis

�  Which is not a characteristic of all organisms?

�  Made of one or more cells

�  Grows and develops

�  Capable of rational thought

�  Maintains homeostasis

�  What area of science takes scientific knowledge and applies it to meet human needs?

�  Exploration

�  Dynamics

�  Physics

�  Technology

�  What area of science takes scientific knowledge and applies it to meet human needs?

�  Exploration

�  Dynamics

�  Physics

�  Technology

�  What is the process of change that takes place during the life of an organism?

�  What is the process of change that takes place during the life of an organism?

�  Development

�  Some species of plants begin opening their flowers in the morning when they are exposed to sunlight. What characteristic of living things does this represent?

�  Some species of plants begin opening their flowers in the morning when they are exposed to sunlight. What characteristic of living things does this represent?

�  Responding to stimulus

�  What process regulates an organism’s internal conditions and keeps them stable?

�  Adaptation

�  Equilibrium

�  Homeostasis

�  Metabolism

�  What process regulates an organism’s internal conditions and keeps them stable?

�  Adaptation

�  Equilibrium

�  Homeostasis

�  Metabolism

�  What is a theory?

�  What is a theory?

�  An explanation supported by observations and experiments

�  Scientists discard observations and data that are not consistent with current scientific understanding.

�  True

�  false

�  Scientists discard observations and data that are not consistent with current scientific understanding.

�  True

�  False—even if the information is false, it is still included in the scientific write-up. This information can be valuable to others working in similar fields.

�  A scientist wants to report the findings from her investigations. Before her information can be published, what must happen?

�  A scientist wants to report the findings from her investigations. Before her information can be published, what must happen?

�  Peer review-others in the same field or conducting similar research will review the information

�  What do issues such as AIDS, global warming, genetic engineering, and cloning have in common?

�  They involve ethics

�  They involve forensics

�  They are examples of pseudoscience

�  They require the metric system

�  What do issues such as AIDS, global warming, genetic engineering, and cloning have in common?

�  They involve ethics (if you are unclear about what ethics and values are, please research it first, then ask for help)

�  They involve forensics

�  They are examples of pseudoscience

�  They require the metric system

�  When you form a logical conclusion based on your observations and what you already know, what are you doing?

�  A conjecture

�  An inference

�  A speculation

�  A theory

�  When you form a logical conclusion based on your observations and what you already know, what are you doing?

�  A conjecture

�  An inference

�  A speculation

�  A theory

�  What type of discovery is a serendipitous discovery?

�  Accidental

�  Anticipated

�  Ingenious

�  Whimsical

�  What type of discovery is a serendipitous discovery?

�  Accidental

�  Anticipated

�  Ingenious

�  Whimsical

�  Identify the term used to describe an explanation of a natural phenomenon supported by observation and experimentation.

�  Forensics

�  Natural law

�  Theory

�  Physics

�  Identify the term used to describe an explanation of a natural phenomenon supported by observation and experimentation.

�  Forensics

�  Natural law

�  Theory

�  Physics

�  Look at the figure. Why is scientific data often displayed in graphs?

�  Look at the figure. Why is scientific data often displayed in graphs?

�  Graphs help show patterns in the data and it is easier to understand