This document provides an introduction to the field of biology, including what science is, how humans explore science through processes like observation and experimentation, and the key characteristics that define life. It discusses topics like the scientific method, cells, homeostasis, growth and development, reproduction, genetics, energy use, responding to the environment, and evolution. The document serves to outline foundational concepts for students beginning to study biology.
2. WHAT IS SCIENCE?
• An organized way of using evidence to learn about
the natural world.
• The word science can also be used to describe
what humans already know about the natural
world.
• It’s important to avoid opinions and biases in
science so actual facts can be presented.
3. HOW DO HUMANS EXPLORE SCIENCE?
• Observe
• Describe
• Experiment
• Read
• Research
• Explore
• What are some words or processes that come to
mind when you think about exploring science?
5. OBSERVATION
• Involves observing something with one or more of
your senses
• Using your senses to gather information
• Which senses do you believe would be most useful
in gathering scientific information or data?
• Sight
• Sound
• Touch
• Smell
• And sometimes even taste
6. OBSERVATION
• 1. Quantitative- involves numbers, counting or
measuring
• 2. Qualitative- observations that cannot be counted
or measured
• Observations are used in collecting data and the
formation of evidence
7. EVIDENCE INTERPRETATION
• What happens after the observations are made?
• How are the observations used to provide an
understanding of the process you are trying to
explain?
• Inference: a logical explanation or interpretation
based on prior knowledge/experience of the
subject
8. HOW ARE SCIENTIFIC IDEAS TESTED?
• Once someone has formed a scientific question
what is the next step?
• The Scientific Method can be used to test a
hypothesis.
9. THE BASIC STEPS
• 1. Ask a Question
• 2. Form a Hypothesis
• 3.Design and Conduct an Experiment
• 4. Analyze Results of the Experiment
• 5. Draw Conclusion
11. HYPOTHESIS
• Can answer a scientific question
• Can describe scientific information
• A possible explanation
• Hypotheses can be tested usually through
controlled experimentation
• Sometimes hypotheses are wrong
• In an If…then format
12. ALTERNATIVE HYPOTHESES
• H 1, H 2, H 3
• Alternative hypotheses are more likely to be correct
• Multiple alternative hypotheses can be generated
and tested.
14. NULL HYPOTHESIS
• H0
• The null hypothesis is a hypothesis which the researcher
tries to disprove, reject or nullify
• The 'null' often refers to the common view of something,
while the alternative hypothesis is what the researcher
really thinks is the cause of a phenomenon.
15. THE STEPS
• Do all scientific investigations include all the steps?
• No
• Do some investigations include more steps?
• Yes
• The scientific method is the basis for scientific
investigation, but it is not set in stone.
• It is a process to help direct scientific inquiry, more
steps, research, or experimentation can be
necessary.
17. CR: 3
Why is the scientific method important
for answering scientific questions? Do
your best to describe the process of
the scientific method step by step.
18. THE PROCESS OF SCIENTIFIC
INVESTIGATION
• The Process of Scientific Investigation can be done
in a series of stages, formal research and testing is
carried out in this manor.
• 1. Observations
• 2. Form Hypotheses
• 3. Predictions
• 4. Experimentation
• 5. Make conclusions
19. EXPERIMENTAL DESIGN
• Developing and setting up a controlled experiment
to test your hypothesis
• Controlled Experiment: When only one variable is
changed at a time
• Manipulated variable: variable that is deliberately
changed
• Responding variable: variable that is observed and
changes in response to the manipulated variable
20. MORE ON VARIABLES
• Independent Variable- researcher can control,
concentration of a chemical, timing of
measurements
• (manipulated variable)
• Dependent Variable- response that is measured
• (responding variable)
21. CONTROLLED EXPERIMENTS
• What does it mean to have a controlled
experiment?
• When an experiment is run, one variable is altered
and the all other variables will remain constant.
• A controlled experiment will be run the same way
but no variables will be altered and all other
variables will be kept constant.
23. THEORIES
• Once you have supported your hypothesis through
testing does it become a theory?
• What is a theory?
• A theory is a well supported explanation involving a
broad range of observations for a particular
phenomenon
• Multiple investigations have been done and proven the
hypothesis to be true
24. THEORIES
• Theories can be widely excepted, but should not be
considered absolute truth
• New evidence may be uncovered
• New technologies can lead to new discoveries
25. REDI’S EXPERIMENT
• In ancient times people did not understand many
biological lifecycles, people accepted the idea
that some organisms, fruit-flies, maggots, would
suddenly just appear
• Spontaneous Generation- sudden appearance of
organisms from non-living matter
26. REDI’S EXPERIMENT
• In 1668 Francesco Redi observed flies on meat and
several days later the appearance of maggot, he
wanted to test his hypothesis that maggots came
from flies and developed a controlled experiment.
• He used 8 jars, 4 he left open to the air and 4 he
covered with muslin, a fabric that prevented flies
from getting to the meat.
28. REDI’S EXPERIMENT
• What was the control group?
• The jars that were left uncovered
• This was the way meat was typically kept
• His hypothesis was that flies were causing the production
of maggots on the meat
• He was able to prove that the flies were causing the
maggots by covering the jars, preventing the flies from
laying eggs in the meat.
29. VARIABLES IN REDI’S EXPERIMENT
• Manipulated Variables:
• Muslin covering the jars
• Responding Variables:
• The maggots appearing or not
• Variables that were controlled:
• Jars, type of meat, location, temperature, time
30. JOHN NEEDHAM
• Mid-1700’s
• Englishman
• Used a sealed jar of gravy to try and disprove Redi’s
claim on spontaneous generation
• He took a jar of gravy and sealed it
• He then heated the gravy “killing off all possible
microorganisms”
• After several days he examined the gravy, found
microorganisms and claimed they could have only
came from the gravy, since the jar was sealed.
31. JOHN NEEDHAM
• Why do you think there were organisms in the
gravy?
• Do you think Needham’s findings disproved the
work of Redi?
• Was Needham’s experiment controlled?
32. SPALLANZANI’S EXPERIEMENT
• Italian Scholar
• An improvement on Needham’s experiment
• He believed that the gravy had not been heated
enough to kill all the existing microorganisms
• Preformed a similar experiment to Redi’s
33.
34. SPALLANZANI’S EXPERIMENT
• Spallanzani claimed that the gravy left open grew
microorganisms that had entered from the air, the sealed flask
had no living organisms.
• He concluded that non-living gravy could not produce living
things
• What was the control group in Spallanzani’s experiment?
• Gravy flask left unsealed
• The manipulated variable was the sealing of the flask
• The responding variable was microorganism growth
• He sealed the flask and prevented microorganism growth
35. LOUIS PASTEUR
• Famous problem solver, Microbiologist
• In 1864 Louis Pasteur designed a flask with a curved
neck so that air could get into the flask, but
microorganisms could not
• Other works of Pasteur
• Saved French wine industry when wine was souring
• Saved the silk industry through discovery of a silkworm
disease
• Discovered and worked with infectious diseases
• Vaccine for Anthrax bacterial infection in 1881
38. CAN EVERYTHING SCIENTIFIC BE
TESTED BY EXPERIMENTATION?
• Animal and insect life cycles
• The Great White Shark is hard to keep in captivity
• Ecological Interactions
• How do you simulate all the different environmental factors
in a controlled way?
• Human Ethics
• Stem cell research
• Testing on humans and animals
39. ALTERNATIVES TO CONTROLLED
EXPERIMENTS
• Field Studies
• Observation of animals or other living things in their natural
environment
• Studies involving large amounts of people or subjects
• More samples gives more reliable data
• Control of as many factors as possible
• In a medical study for cancer, people with other health issues
may be eliminated
• It is important to research what is already out there.
What has been done on the subject?
• Cite your sources!
40. So how are we going to use
this information about
science and the process of
scientific investigation to
learn about Biology?
41. SO WHAT IS BIOLOGY?
• Textbook definition: A field of science that seeks to
understand the living world. The study of life.
• The study of things that are “living”.
• What does it mean to be “alive”?
• What are some characteristics that help people
determine whether something is living or non?
46. THE CHARACTERISTICS OF LIFE
• Made up of units called cells
• Maintain stable internal conditions: homeostasis
• Grow and develop
• Reproduce
• Based on a universal genetic code
• Obtain and use materials and energy
• Respond to their environment
• When looking at a species as a whole, living things
can change over time or evolve
47. THE CELL
• What is a Cell?
• A cell is a collection of living matter surrounded by
a membrane that separates it from its surrounding
environment.
• How are cells organized?
50. CELLULAR ORGANIZATION
• All living things are made up of one or more cells
• Cells can be simple to very complex
• Cells can grow and reproduce
• Single-Celled Organisms
• Algae
• Bacteria
• Paramecia, A protist
• There are around 100 trillion cells in the human body
51. HOMEOSTASIS
• Living things must expend energy to keep their cells
within certain limits for proper form and function
• Organisms are able to maintain certain internal
environments even when the environment outside
of them is constantly changing
• An organism's ability to do this allows them to
survive
53. GROWTH & DEVELOPMENT
• Every different organism has a specific
pattern of growth
• A single egg cell once fertilized can divide
over and over
• Cells differentiate forming tissues and organs
60. UNIVERSAL GENETIC CODE
• Information needed to live and grow is stored in
complex molecules called DNA
• DNA stores the information for genes and traits of an
organism
• DNA is the method for passing down genetic
information to the next generation
61. USE OF MATERIALS AND ENERGY
• Organisms must use materials from the earth and
energy from the sun to live and grow
• Chemicals/Nutrients from the earth
• Energy from the sun helps plants and other
photosynthetic organisms produce food
62. METABOLISM
• Living things need energy
• Life functions require energy
• Transforming energy from one form to another with
in cells is metabolism
63. RESPOND TO THEIR ENVIRONMENT
• Organisms can detect and react to different signals
within their environment
• Stimuli: signal to which an organism responds
64. EVOLVE OVER TIME
• Populations of organisms change over time
• Natural selection: Individuals more well suited for
their environment will do better and will reproduce
more then other individuals
65. CR:4
• What does it mean to be alive? Discuss what it
means to you; think about the characteristics of life.
• Or
• Design an experiment: If you were given an
unknown substance, what kinds of tests could you
preform to find out if that item was living or non-
living?
66. CHARACTERISTICS OF LIFE
ASSIGNMENT
• Today you will explore all the characteristics of life
for a single organism
• Pick any organism you would like, tell you instructor
what you choose; grab paper, pencils, markers,
whatever you would like to use
• Make a flow diagram of your organism fulfilling all
the different characteristics of life.
67. SCIENTISTS OF BIOLOGY
• Zoologists: Animals
• Botanists: Plants
• Ethologists: Animal Behavior
• Paleontologists: Life in the past
68. LEVELS OF ORGANIZATION
• Molecules
• Cells
• Groups of cells
• Organism
• Population community
• Ecosystem
• Biosphere
69.
70. • CR:5
• Describe how you fulfill the 8
characteristics of life. Use your
notes if you can’t remember
all 8.
