Name: __KEY_______________________________________
Period: ____
Date: ______________
Introduction to Biology
Lesson 1: Unifying Principles of Biology
Four Unifying Principles of Biology The “Big Ideas”
1. What are the four unifying principles of biology?
_ Evolution…. Free Energy… Information… Systems… ______________________________
-Evolution
2. Who developed the theory of evolution? _Charles Darwin_______________________________
3. What is the main driving force of evolution? _Natural Selection___________________________
4. What are the four other factors that drive evolution?
_ Small populations, non-random mating, genetic mutations, and immigration and emigration _
5. Define phylogeny.
_ Describes the characteristics of the various species from which an organism descended—
together with its genealogical relationship to every other species on Earth__________________
6. What major misconception about evolution exists today?
_ Some people think the theory of evolution means that humans evolved from modern apes.___
CHECKPOINT:
7. Why is evolution considered one of the unifying themes of biology?
_ Evolution drives the diversity and unity of life._______________________________________
-Free Energy
8. What occurs through the gathering, storage, and manipulation of free energy?
_Biological life processes__________________________________________________________
9.
What is the initial source for free energy in biological life processes? _photons or sunlight_____
10. Your text states that : “Free energy is used by living organisms through a chain of coupled
reactions or processes which pass free energy from one form to another.”
a. Explain how and what photosynthetic organisms use free energy for?
_How…Photosynthetic organisms harness energy from the photons in sunlight. The reactions
which allow the photosynthetic process to occur are endergonic reactions, reactions that
require energy in order to proceed (the sun provides this energy). Plants use the sun’s energy,
carbon dioxide in the atmosphere, and water to make sugar (glucose) and oxygen through the
process of photosynthesis. The sugar made by plants is a complex organic (carbon-rich)
compound which stores free energy to be used by both plants and other organisms. As complex
organic compounds are broken down or built up through metabolic processes in organisms,
energy is released or stored. What…Photosynthetic organisms harness free energy from
sunlight for the production of glucose, which is later used in cellular respiration for the
production of ATP (adenosine triphosphate)._________________________________________
b. What does the process of cellular respiration use free energy for?
_During cellular respiration, glucose is broken down into carbon dioxide and water and the
energy that is released is used to make another chemical compound called ATP, adenosine
triphosphate. ATP is one of the most important biological molecules that stores free energy in a
form that is easily accessible for use by living cells. ATP is a high-energy molecule which releases
energy when it is broken down into ADP (adenosine diphosphate) and inorganic phosphate
(Pi).The reactions which allow the cellular respiration process to occur are exergonic reactions;
energy is released as a result of the reaction. _________________________________________
11. Define bioenergetics.
_ Bioenergetics is sometimes referred to as biological thermodynamics and can generally be
thought of as the study of energy transformations in biological sciences.____________________
12. Look at the diagram below and explain what this diagram shows.
_ It shows how humans, who cannot photosynthesize obtain chemical energy through
consumption. They are able to use the consumed chemical energy after breaking down the
chemical bonds through the metabolic process of cellular respiration releasing the stored energy
and a small amount of heat. During cellular respiration, glucose (one of the chemical energy
sources) is broken down into carbon dioxide and water which is released as chemical waste. The
energy that is released by cellular respiration is used to make another chemical compound
called ATP, adenosine triphosphate. ATP fuels further metabolic processes releasing more heat
as it does. The reactions which allow the cellular respiration process to occur are exergonic
reactions; energy is released as a result of the reaction._________________________________
2
13. What do homeostatic mechanisms regulate through the use of feedback mechanisms?
_ Homeostatic mechanisms regulate internal conditions such as pH levels, temperature, and
fluid levels through feedback mechanisms found in the certain organ systems._______________
14. Where does the energy come from for homeostatic processes? _Harnessed free energy_______
15. Define feedback mechanisms. (NEED TO HAVE WATCHED EMBEDDED VIDEO TO ANSWER THIS)
_Negative feedback: receptors in body detect when something is off balance and turn on an
effector (something that causes a reaction). Effectors restore balance and then the receptor is
turned off.______________________________________________________________________
16. Looking at and reading Figure 1.9 on page 5 of your textbook, identify as many feedback
mechanisms as you can in this diagram below:
_Body temperature above normal: Nervous system signals dermal blood vessels to dilate and
sweat glands to secrete. OR…Body temperature below normal: Nervous system signals dermal
blood vessels to constrict and sweat glands to remain inactive. OR Body temperature continues
to drop: Nervous system signals muscles to contract involuntarily generating body heat._______
CHECKPOINT:
17. Why is free energy considered one of the unifying themes of biology?
_ Biological systems utilize free energy and molecular building blocks to grow, to reproduce, and
to maintain dynamic homeostasis. __________________________________________________
-Information
18. What molecule stores the biological information that flows from one living organism to
another? _DNA (deoxyribonucleic acid)_____________________________________________
19. What can this molecule do?
_ DNA can store and transmit hereditary information, replicate, synthesize proteins, and direct
cell functions.__________________________________________________________________
20. Define chromosome.
_ A structure made up of DNA.____________________________________________________
21. Define gene.
_ A segment of DNA on a chromosome that controls a particular hereditary trait._____________
22. Define transcription.
_Making a copy of the DNA molecule.________________________________________________
23. Define translation.
_Reading the copy of the DNA molecule._____________________________________________
3
24. What does the ‘central dogma of biology’ state?
_The ‘central dogma of biology’ simply states that DNA is transcribed to RNA (ribonucleic acid)
and RNA is translated into proteins by the cell. It is scientific symbolized as: DNA  RNA 
Proteins._______________________________________________________________________
CHECKPOINT:
25. Why is ‘information’ considered one of the unifying themes of biology?
_ Living systems store, retrieve, transmit, and respond to information essential to life processes.
-Systems
26. Define ‘hierarchy of life’.
_ The arrangement of biology structures and systems that encompass all living organisms. Each
level classified above another level represents an increase in organizational complexity, with
each level being primarily composed of the previous levels basic
unit.___________________________________________________________________________
27. The hierarchy of life extends from _ biological _ to _ecological__ levels of organization.
28. Which levels of organization represent the highest organizational complexity in Diagram 1
below? _biosphere____________ in Diagram 2 below? _organism____________________
Diagram 1
Diagram 2
4
29. What two biological system interactions helps to create genetic diversity?
_Evolution and Interdependence of living organisms.__________________________________
30. Define biodiversity.
_ The diversity of living things.____________________________________________________
31. What is symbiosis?
_ Symbiosis is a close relationship between organisms of different species in which at least one
of the organisms benefits. ________________________________________________________
32. What is competition?
_ Competition is a relationship between living things that depend on the same resources. The
resources may be food, water, or anything else they both need. Competition occurs whenever
they both try to get the same resources in the same place and at the same time. The two
organisms are likely to come into conflict, and the organism with better adaptations may win
out over the other organism.______________________________________________________
CHECKPOINT:
33. Why are ‘systems’ considered one of the unifying themes of biology?
_ Biological systems interact, and these systems and their interactions possess complex
properties. ____________________________________________________________________
Lesson 2: Discovery of Cells and Microscopes…Read Lesson 2, pages 10-15 and explore all embedded
links.
DISCOVERY OF CELLS
1. What is the basic unit of the structure and function of all living things? _The cell_____________
2. Who gave cells their name? _Robert Hooke__________________________________________
3. What did Leeuwenhoek discover?
_ Leeuwenhoek discovered tiny animals such as rotifers. He also discovered human blood cells.
He scraped plaque from his own teeth and observed it under the microscope, in the plague he
saw tiny living things with a single cell that he named animalcules (‘‘tiny animals”). Today, we
call Leeuwenhoek’s animalcules bacteria. ________________________________________
-The Cell Theory
4. The ideas of three scientists led to the development of the cell theory, who were these
scientists? _ Schwann, Schleiden, and Virchow ________________________________________
5
5. List below what the cell theory states:
_(1) All organisms are made of one or more cells.(2) All the life functions of organisms occur
within cells. (3) All cells come from already existing cells._______________________________
CHECKPOINT:
6. Thinking back to Lesson 1 and the four unifying principles of biology: evolution, free energy,
information, and systems; under which unifying principles would the cell theory be classified?
Explain the reasoning behind your choice.
_Either INFORMATION OR SYSTEMS_________________________________________________
_INFORMATION: Cells are essential to life processes because all the life functions of organisms
occur within cells. SYSTEMS: Biological systems interact and all organisms are made of cells that
come from pre-existing cells. ______________________________________________________
-Microscopes
7. What do electron microscopes use to view extremely small objects? _Electron beams________
8. Why did we need to develop electron microscopes in the 1950s?
_ By the late 1800s, light microscopes had reached their limit. Objects much smaller than cells,
including the structures inside cells, were too small to be seen with even the strongest light
microscope.____________________________________________________________________
9. What were scientists now able to see because of electron microscopes?
_The tiny structures inside cells (organelles), they could even see individual molecules and
atoms. _______________________________________________________________________
10. What new field of biological study arose because of electron microscopes?
_Molecular biology_____________________________________________________________
11. Why are compound light microscopes called compound light microscopes?
_ Compound deals with the microscope having more than one lens. The term light refers to the
method by which light transmits the image to your eye. Microscope is the combination of two
words; ”micro” meaning small and ”scope” meaning view._____________________________
12. Name the two most powerful types of microscopes in the world before Lawrence Berkeley
National Labs built their $27 million electron microscope.
_SEM (scanning electron microscope) and TEM (transmission electron microscope)__________
13. Which powerful electron microscope can produce 3-D images of a specimen? _SEM_________
14. Which powerful electron microscope produces only one dimensional images? _TEM__________
15. What is the electron microscope called that Lawrence Berkeley National Labs built called?
_TEAM (Transmission Electron Aberration-Corrected Microscope)________________________
6
CHECKPOINT:
16. Why are microscopes important to biological studies?
_The microscope opened up an amazing new world—the world of life at the level of the cell. It
also has allowed scientists to study organisms at the level of their molecules and led to the
emergence of the field of molecular biology._________________________________________
Lesson 3: The Nature of Science…Read Lesson 3, pages 16-22 and explore all embedded links.
1. What is the goal of science?
_ To learn how nature works by observing the natural and physical world, and to understand
this world through research and experimentation.____________________________________
2. Define science.
_ Science is a distinctive way of gaining knowledge about the natural world that starts with a
question and then tries to answer the question with evidence and logic. Science is an exciting
exploration of all the whys and hows that any curious person might have about the world.
Science is a way to get some of those “whys” answered.________________________________
-The Goal of Science
3. Name the four things that all scientific studies involve.
_ Asking questions, making observations, relying on evidence to form conclusions, and being
skeptical about ideas or results.____________________________________________________
4. Define skepticism.
_ Skepticism is an attitude of doubt about the truthfulness of claims that lack empirical
evidence. Scientific skepticism also referred to as skeptical inquiry, questions claims based on
their scientific verifiability rather than accepting claims based on faith or anecdotes. Scientific
skepticism uses critical thinking to analyze such claims and opposes claims which lack scientific
evidence._______________________________________________________________________
5. True/ False Nature can be understood by discovering natural laws.
6. Define scientific law.
_ A statement that describes what always happens under certain conditions in nature.________
7. True/ False Scientific ideas never change.
8. What is a scientific theory?
_Scientific knowledge that has withstood the test of time. A broad explanation for events that is
widely accepted as true. To become a theory, a hypothesis must be tested over and over again,
and it must be supported by a great deal of evidence. ______________________________
9. What types of things can science answer questions about?
7
_ Science rests on evidence and logic, so it deals only with things that can be observed. Science
can answer questions about an observation, anything that is detected either through human
senses or with instruments and measuring devices that extend human senses. ______________
10. What types of questions cannot be answered by science?
_ Things that cannot be observed or measured by current means—such as supernatural beings
or events—are outside the bounds of science._______________________________________
CHECKPOINT:
11. Explain why science cannot provide answers to all questions.
_Science can only answer questions on the basis of scientific evidence and logic, science cannot
answer questions based on beliefs because they cannot be observed or measured. Therefore, it
is outside the realm of science.________________________________________________
-The Scientific Method
12. Define scientific investigation.
_ A scientific investigation is a plan for asking questions and testing possible answers._______
13. List all the steps of the scientific method and briefly explain each step.
a. _ Making Observations
_Using your senses and curiosity to wonder about the world around you________________
b. _ Asking a Question
_ Observations often lead to questions. __________________________________________
c. _ Forming a Hypothesis
_ A hypothesis is a possible answer to a scientific question, but it isn’t just any answer. A
hypothesis must be based on scientific knowledge, and it must be logical. A hypothesis also
must be falsifiable. In other words, it must be possible to make observations that would
disprove the hypothesis if it really is false. _________________________________________
d. _ Testing the Hypothesis
_ To test a hypothesis, you first need to make a prediction based on the hypothesis. A
prediction is a statement that tells what will happen under certain conditions. It can be
expressed in the form: If A occurs, then B will happen._______________________________
e. _ Drawing Conclusions
_ Evidence that agrees with your prediction supports your hypothesis. Does such evidence
prove that your hypothesis is true? No; a hypothesis cannot be proven conclusively to be
true. This is because you can never examine all of the possible evidence, and someday
evidence might be found that disproves or refutes the hypothesis. Nonetheless, the more
8
evidence that supports a hypothesis, the more likely the hypothesis is to be true. _______
f.
_ Communicating Results
_ The last step in a scientific investigation is communicating what you have learned with
others. This is a very important step because it allows others to test your hypothesis. If
other researchers get the same results as yours, they add support to the hypothesis.
However, if they get different results, they may disprove the hypothesis.________________
CHECKPOINT:
14. Explain how a hypothesis could become a theory.
_ To become a theory, a hypothesis must be tested over and over again, and it must be
supported by a great deal of evidence. In other words it has been through the scientific method
process numerous times._________________________________________________________
-Experiments
15. What is a variable in an experiment?
_The thing being tested.__________________________________________________________
16. Define dependent variable.
_The affected variable is called the dependent variable.________________________________
17. Define independent variable.
_The variable that affects the dependent variable is called the independent variable.__________
18. What is a sample in an experiment?
_The sample in an experiment or other investigation consists of the individuals or events that
are studied._____________________________________________________________________
CHECKPOINT:
19. Identify the independent and dependent variables in the following experiment:
A scientist grew bacteria on gel in her lab. She wanted to find out if the bacteria would grow
faster on gel A or gel B. She placed a few bacteria on gel A and a few on gel B. After 24 hours,
she observed how many bacteria were present on each type of gel.
_Dependent variable is the bacteria. Independent variable is the different types of gel, A or B.__
-Other Types of Scientific Investigations
20. What are the other two types of scientific investigations mentioned in your textbook and briefly
describe each type.
_ (1) Natural studies: you study things in their natural habitat, you cannot control variables. (2)
Modeling: A model is a representation of part of the real world. Models are especially useful for
investigating complex systems. By using a model, scientists can better understand how the real
system works.__________________________________________________________________
9