Summer Assignments for AP BIOLOGY. All work is to be done by individual students. Below is a checklist for all of your summer assignments. Please read and make sure you have everything done by the due date.

1) Read one of the books on the AP Biology summer reading list provided, and complete a 3+ page review following the instruction on the reading list. Due Date: September 4, 2018.

2) Log onto Google Drive and create a folder that is sharable with Ms. Emami (It should be called AP Bio First name Last name for ex. AP Bio Dali Emami). All assignments that are to be electronically submitted this school year will go into this folder. Due Date: September 4, 2018

3) We will be starting with some introductory material and a review of chemistry this year. As such there are some chemistry review questions. Much of the information that these questions address are considered, by the AP folks, to be prerequisite knowledge and therefore may not be addressed directly in class. Due Date: Sept 4, 2018 in Google Drive AP Bio Folder or by hard copy to Ms. Emami

4) Graphing Packet. You must answer every question and draw every graph requested. When a question asks you to "describe what the graph shows," look at the overall picture and trends, not just the apex/highest point. Also do not just repeat the description under the figure #. For example Figure 2.10 has “Change in world population from 1650 to 2000.” DO NOT just write the same words for your interpretation. Describe the changes and pattern that you actually see within the graph. Making and interpreting graphs is an important part of biology. Every AP exam has a few questions about graphs. The AP Exam has also frequently had students make and interpret a graph on an essay question. This is a basic skill that you need to do well in any AP science class. You should complete this packet before performing any labs. While I will expect you to use computer generated graphs in the year, I want these graphs made by hand. This will ensure academic integrity. You may then scan them and turn them into your AP Bio Google folder. Due Date: Electronic or Hard copy due September 4, 2018

If you have any questions, please feel free to contact me at daliemami@ccs.k12.nc.us. I may not get back to you the very same day, but I frequently check my school email. Have a great summer. I look forward to working with you! Ms. Emami

AP BIOLOGY SUMMER READING Selection List

Read one of the following books, write a 3+ page review on the book you read. The review 

must include a summary and a personal commentary/reaction to the book. Reviews must be 

submitted by Tuesday, September 4, 2018. 

The Demon-Haunted World by Carl Sagan

A book about what science really is, and how the scientific method fights ignorance and superstition.

Very well written, and probably an enjoyable read for anyone.

Approximately 200 pages.

T. Rex and the Crater of Doom by Walter Alvarez

A book about the extinction of the dinosaurs and the search and collaboration of many scientists to

develop the “mass impact” theory of extinction and discover the evidence to support it. Quite Short.

The Beak of the Finch by Jonathan Weiner

A book about the Finches of the Galapagos islands and evolution. Infinitely better than the Origin of the

Species. Fairly long, at least 500 pages.

Origin of the Species (Any Version) by Charles Darwin

A boring book on evolution, but the original. Tried and true. Read an abbreviated version if you can find

one – the regular one talks way too much about pigeons. Unabridged version approximately 450 pages.

A Natural History of the Senses by Diane Ackerman

A discussion of taste, touch, smell, sight, and hearing. Not terribly scientific, but written by a truly

excellent writer. It discusses the history of perfume, the meaning of communal eating, and much more.

Written for the layperson. About 200 pages.

On Aggression by Konrad Lorenz

A book about competition between tropical fish around the coral reef. Lorenz and competition are

always AP Bio topics.

Silent Spring by Rachel Carson

A very famous book indeed. Recommended by The Times magazine. Mentioned in the 2003 AP Bio

Exam and the Bio SAT II.

Your Inner Fish: A Journey into the 3.5-Billion-Year History of the Human Body by Neil Shubin

Parsing the millennia-old genetic history of the human form is a natural project for Shubin, who chairs

the department of organismal biology and anatomy at the University of Chicago and was co-discoverer

of Tiktaalik, a 375-million-year-old fossil fish whose flat skull and limbs, and finger, toe, ankle and wrist

bones, provide a link between fish and the earliest land-dwelling creatures.

The Book of Life: An Illustrated History of the Evolution of Life on Earth by Stephen Jay Gould

(Editor)

A lucid, readily comprehensible, and largely up-to-date overview of the origins and evolution of life on

earth, from the emergence of bacteria 4 billion years ago to that of Homo sapiens in recent geological

time. Written by distinguished scientists, the text proceeds chronologically, giving an in-depth account

of the fossil record. It is matched by hundreds of paintings, drawings, charts, and graphs that reinforce

the author’s discussions.

Your Brain on Food: How Chemicals Control Your Thoughts and Feelings by Gary Wenk (Author)

Why is eating chocolate so pleasurable? Can the function of just one small group of chemicals really

determine whether you are happy or sad? Does marijuana help to improve your memory in old age? In

this book, Gary Wenk demonstrates how, as a result of their effects on certain neurotransmitters

concerned with behavior, everything we put into our bodies has very direct consequences for how we

think, feel, and act.

Dead Men Do Tell Tales: The Strange and Fascinating Cases of a Forensic Anthropologist

William R. Maples, Michael Browning (Authors)

Noted forensic anthropologist Maples, whose specialty is the study of bones, and freelance journalist

Browning here recount Maples' criminal and anthropological investigations over the past 20 years. The

book's strength is as a snapshot of the world of forensic scientists. ***

The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry

Bryan Sykes (Author)

Sykes is passionate about his work in decoding mitochondrial DNA and about using this knowledge to

trace the path of human evolution. To lure readers into this specialized work, he relates personal and

historical anecdotes, offering familiar ground from which to consider the science. A discussion of the

history of genetics and descriptions of the early landmark work of Sykes and his associates culminate

with his finding that 90 percent of modern Europeans are descendants of just seven women who lived

45,000 to 10,000 years ago. ***

Welcome to Your Brain: Why You Lose Your Car Keys but Never Forget How to Drive and

Other Puzzles of Everyday Life

Sam Wang (Author), Sandra Aamodt (Author)

Neuroscientists Aamodt, editor-in-chief of Nature Neuroscience, and Wang, of Princeton University,

explain how the human brain—with its 100 billion neurons— processes sensory and cognitive

information, regulates our emotional life and forms memories. They also examine how human brains

differ from those of other mammals and show what happens to us during dreams. ***

The Biophilia by Stephen R. Kellert (Editor)

Why is it that most of us find baby animals irresistibly cute? Why do so many people fear even the

sight of snakes? Stephen Kellert and Edward Wilson, the prolific Harvard biologist, gather essays by

various hands on these and other questions, and the result is a fascinating glimpse into our relations

with other animals. Humans, Wilson writes, have an innate (or at least extremely ancient) connection

to the natural world, and our continued divorce from it has led to the loss of not only "a vast

intellectual legacy born of intimacy" with nature but also our very sanity. ***

Plague of Frogs: Unraveling an Environmental Mystery

William Souder (Author)

A Plague of Frogs is an ecological detective story, one that begins when a class of middle schoolers

discovers an unusual number of deformed frogs in a pond on a southern Minnesota farm in 1995.

William Souder spins a gripping tale of scientific investigation, environmental debate, and the

frightening implications of what these deformed frogs mean for humanity. This is a superb account of a

disturbing environmental happening, which finally leaves us wondering, as scientists do, over its larger

implications."

The Immortal Life of Henrietta Lacks by Rebecca Skloot (Author). Senior only.

From a single, abbreviated life grew a seemingly immortal line of cells that made some of the most

crucial innovations in modern science possible. Henrietta Lacks was a mother of five in Baltimore, a

poor African American migrant from the tobacco farms of Virginia, who died from a cruelly aggressive

cancer at the age of 30 in 1951. A sample of her cancerous tissue, taken without her knowledge or

consent, as was the custom then, turned out to provide one of the holy grails of mid-century biology:

human cells that could survive--even thrive--in the lab.

Genome: The Autobiography of a Species in 23 Chapters

Matt Ridley (Author)

Each chapter pries one gene out of its chromosome and focuses on its role in our development and

adult life, but also goes further, exploring the implications of genetic research and our quickly changing

social attitudes toward this information. Genome shies away from the "tedious biochemical middle

managers" that only a nerd could love and instead goes for the A-material: genes associated with

cancer, intelligence, sex (of course), and more.

Lives of a Cell: Notes of a Biology Watcher by Lewis Thomas (Author)

Thomas explores the world around us and examines the complex interdependence of all things.

Extending beyond the usual limitations of biological science and into a vast and wondrous world of

hidden relationships, the book explores in personal, poetic essays topics such as computers, germs,

language, music, death, insects, and medicine.

The Youngest Science: Notes of a Medicine-Watcher

Lewis Thomas (author)

A doctor's fascinating view of what medicine was, and what it has become. Thomas first learned about

medicine by watching his father practice in an era when doctors comforted rather than healed. Looking

back upon his experiences as a medical student, young doctor, and senior researcher, Thomas notes

that medicine is now rich in possibility and promise.

A General Theory of Love Thomas;Amini, Fari;Lannon, Richard Lewis (Author)

A powerfully humanistic look at the natural history of our deepest feelings, and why a simple hug is

often more important than a portfolio full of stock options. The grasp of neural science is top notch, but

the book is more about humans as social animals and how we relate to others--for once, the brain

plays second fiddle to the heart.

And the Waters Turned to Blood by Rodney Barker (Author)

Don't drink the water. Don't swim in it, fish in it, or even bathe in it. Rodney Barker's book details the

latest plague to visit our shores: Pfiesteria piscicida, the "cell from hell," an aquatic microorganism that

causes sufferers to exhibit symptoms similar to Alzheimer’s or multiple sclerosis and the government’s

attempts to suppress reports.

The Hot Zone: A Terrifying True Story Richard Preston (Author)

The dramatic and chilling story of an Ebola virus outbreak in a suburban Washington, D.C. laboratory,

with descriptions of frightening historical epidemics of rare and lethal viruses. More hair-raising than

anything Hollywood could think of, because it's all true.

The Demon in the Freezer Richard Preston (Author)

On December 9, 1979, smallpox, the most deadly human virus, ceased to exist in nature. After

eradication, it was confined to freezers located in just two places on earth: the Center for Disease

Control in Atlanta and the Maximum Containment Laboratory in Siberia. Since the fall of the Soviet

Union in 1991 a sizeable amount of the former Soviet Union's smallpox stockpile remains unaccounted

for, leading to fears that the virus has fallen into the hands of nations or terrorist groups willing to use

it as a weapon.

The Botany of Desire: A Plant's-Eye View of the World

Michael Pollan (Author)

Pollan's fascinating account of four everyday plants and their co-evolution with human society

challenges traditional views about humans and nature. Using the

histories of apples, tulips, potatoes and cannabis to illustrate the complex, reciprocal relationship

between humans and the natural world, he shows how these species have successfully exploited human

desires to flourish.

In Defense of Food: An Eater's Manifesto Michael Pollan (Author)

As an increasing number of Americans are overfed and undernourished, Pollan makes a strong argument

for serious reconsideration of our eating habits and casts a suspicious eye on the food industry and its

more pernicious and misleading practices. Listeners will undoubtedly find themselves reconsidering their

own eating habits.

The Omnivore's Dilemma: A Natural History of Four Meals Michael Pollan (Author) In a

journey that takes us from an "organic" California chicken farm to Vermont,

Pollan asks basic questions about the moral and ecological consequences of our food. Critics agree it's a

wake-up call and, written in clear, informative prose, also entertaining.

Wicked Plants: The Weed That Killed Lincoln's Mother and Other Botanical Atrocities Amy

Stewart (Author), Briony Morrow-Cribbs (Illustrator)

A tree that sheds poison daggers; a glistening red seed that stops the heart; a shrub that causes

paralysis; a vine that strangles; and a leaf that triggered a war. Stewart takes on over two hundred of

Mother Nature’s most appalling creations. It’s an A to Z of plants that kill, maim, intoxicate, and

otherwise offend.

Wicked Bugs: The Louse That Conquered Napoleon's Army & Other Diabolical Insects Amy

Stewart (Author)

With wit, style, and exacting research, Stewart has uncovered the most terrifying and titillating stories

of bugs gone wild. It’s an A to Z of insect enemies, interspersed with sections that explore bugs with

kinky sex lives (“She’s Just Not That Into You”), creatures lurking in the cupboard (“Fear No Weevil”),

insects eating your tomatoes (“Gardener’s Dirty Dozen”), and phobias that feed our (sometimes)

irrational responses to bugs (“Have No Fear”).

                     

  Basic Chemistry Review Directions: If you are planning on using the shared form from within google docs, please make a copy before typing here; otherwise you are typing on the original document. If typed, please type all response in bold directly below the question (yes, you must include the question). Once you are done, please submit this document via google drive. Remember that this is due by Sept. 4, 2018.  

1. Review: J.J. Thomson’s Plum Pudding model and ionic vs. molecular bonding You examined the interactions between positively charged objects, negatively charged objects, and neutral objects. To explain that objects can become charged, J.J. Thomson proposed that atoms have smaller mobile particles in them. Evidence from his Cathode Ray experiments showed that these smaller mobile particles, later called electrons, are negatively charged. For an atom to be neutral, there must be the same number of positive charges to counterbalance the negative charges of electrons. Thomson had no experimental evidence to show where in the atom the positive charges would be. He hypothesized that the interior of an atom was a positive cloud with no mass. It is the attraction between the positive cloud and the negative electrons that holds electrons inside the atom.   

However, atoms of different elements have different abilities to attract electrons. We call this electronegativity. Metal elements have free moving electrons that make metals good conductors of electricity. This suggests that the positive charges in metal atoms attract electrons weakly (low electronegativity). On the other hand, nonmetal elements are poor conductors, suggesting strong attraction (high electronegativity) between the positive charges and electrons. This limits the movement of the electrons between atoms. Because of this difference in electronegativity, a metal atom is more likely to form a positive  ion (cation) when electrons are transferred to a nonmetal atom due  to the higher attraction (higher electronegativity) from the positive charges in the nonmetal atom. The nonmetal atom becomes a negative ion (anion). Thus, the bonding between metal atoms  and nonmetal atoms is ionic, as shown by the diagram to the right. If  the difference in electronegativity between atoms is not enough to 

cause electrons to move from one atom to another, i.e., two nonmetal atoms such as H and Cl, these atoms bond together to form neutral HCl molecules, as illustrated in the diagram on the left. However, the slight difference in electronegativity between H and Cl causes uneven distribution of electrons within the molecule, with the H end of the molecule partially positive (δ+) and the Cl end partially negative (δ-). Thus we call HCl a polar molecule.    

(Recall the tug-of-war analogy we used in describing this situation.)   

A numerical scale of 0 – 4 has been used to compare the electronegativity of main group elements, as shown in the table to the right.   

 

Intermolecular forces: For polar molecules, the δ+ end of one molecule weakly attracts the δ- end of another molecule. This weak attraction between polar 

molecules is call dipole-dipole interaction – one of the intermolecular forces that plays vital role in biological systems.   

 

 2. Atomic models beyond Thomson’s Plum Pudding Model 

Over ten years after J.J. Thomson proposed his Plum Pudding model of an atom, Ernest Rutherford, a former student of Thomson’s, proposed a nuclear model of an atom based on evidence collected from his famous gold foil experiment.   

Rutherford suggested that the positive charges in an atom are concentrated in a very small but dense center of the atom that he called a nucleus. Almost all the mass of the atom is also in the nucleus. Without any evidence on where electrons are in the atom, Rutherford hypothesized that electrons are moving around the nucleus. Thus, according to Rutherford’s model, atoms are made of mostly empty space. Later, based on the experimental work by Henry Moseley, James Chadwick and others, scientists proposed that the nucleus is made of positively charged protons and neutral neutrons. Both protons and neutrons have mass, with neutrons slightly more massive than protons. Therefore the number of protons in the nucleus must be the same as the number of electrons so that the atom is neutral.   

A comparison of Dalton, Thomson, and Rutherford model is shown in the diagram below. 

 Meanwhile, other scientists, including Niels Bohr, Louis de Broglie, Werner Heisenberg, Erwin Schrodinger and others, took interests in studying the electrons of an atom. Bohr took the idea of quantized (discrete packets, or amounts) energy from Max Planck and Albert Einstein and then calculated the energy levels for the electrons outside the nucleus. He proposed a model of an atom with electrons moving in circular orbits around the nucleus like the planets orbit the sun. Electrons in orbits closer to the nucleus are more attracted by the positive protons in the nucleus, therefore have less energy. (Recall, the generalization that the more attracted the particles are to each other, the closer the particles are, therefore the less potential energy is stored.) The farther away from the nucleus, the more energy electrons have. However, his model could only explain the experimental results of hydrogen atoms which has only one electron in each atom. All 

the other elements have multiple electrons in their atoms. So a better atomic model was needed to explain experimental observations of all atoms.   

 

Eventually, based on the work from many scientists, a modern quantum atomic model emerged. In this model, electrons do move around the nucleus with protons and neutrons in it. However, electrons do not have fixed orbits. Instead, electrons behave not only as discrete particles, but also as waves. (Recall light and other electromagnetic radiations as waves.) This is a bit difficult for us to imagine. A cartoon video at the following link explains the basic idea of the dual property of electrons. http://www.youtube.com/watch?v=x_tNzeouHC4 

Because of this particle-wave property of electrons, the actual location of an electron at any given moment cannot be determined. Based on the energy of an electron, we can only know the probability of electron appearance in the space outside the nucleus. Generally speaking, low energy electrons are mostly likely to appear in the space close to the nucleus while high energy electrons are more likely to appear in the space farther away from the nucleus. The outermost electrons of an atom have highest energy and are most “active”. We call these electrons valence electrons. These electrons are the ones primarily involved in chemical bonding, which will be discussed in the next section. 

The comparison of Bohr model and the quantum model of a single-electron atom is shown in the figure below. In the quantum model, the map of the probable locations of the electron is usually called electron cloud.   

  

   

3. An evolved view on bonding based on the quantum atomic model As discussed in the previous section, high energy valence electrons are farther away from the nucleus. They are less attracted by the positive nucleus. Furthermore, they are also repelled by the inner electrons, those electrons closer to the nucleus. As a result, valence electrons are more likely to “jump” to another atom when the nucleus of the other atom exert much more attraction to these electrons than their own nucleus. This is the case of ionic bonding between metal atoms and nonmetal atoms, as was discussed in the Thomson model. For example, in the compound NaCl, the significant difference in electronegativity between Na (0.9) and Cl (3.0) causes the transfer of the only valence electron of the Na atom to the Cl atom, thus forming Na+ and Cl- in this ionic compound.   

 In the case of molecular compounds, which are made of all nonmetal atoms, valence electrons are not able to completely “jump” from one atom to another because both nonmetal elements have high electronegativity with not too much of a difference. Let’s still use H and Cl as an example. The electronegativity of Cl is 3.0, while for H it is 2.1. The valence electron of H and one of the valence electrons of Cl are mostly found in the region between the two nuclei, in other words, the electron clouds overlap. This kind of electron sharing between nonmetal atoms is called covalent bonding. Since Cl has higher electronegativity, the most probable locations of finding these two valence electrons are closer to Cl than H, thus a polar covalent bond.  

The following diagram illustrates the difference between nonpolar covalent, polar covalent and ionic bonds based on the difference in electronegativity between the two atoms.  

 

  

         

Basic Chemistry Directions: If typed, please type all response in bold directly below the question. Due by September 4, 2018. 1) Look up Lewis Dot diagrams for H2 and F2 how are they different? 2) What, if anything, about these structures could account for the differences in their boiling points?

Element boiling pt. (K)

Hydrogen

20

Nitrogen 77

Oxygen 90

Fluorine 85

Chlorine 239

Bromine 332

Iodine 457

3) Go to the following website: http://phet.colorado.edu/en/simulation/molecule-polarity and click on Run Now! (You may have to download it.) After the window loads, you should see a blue screen with two atoms A and B. They are connected together by a covalent bond. On the right hand side of the screen, there will be a box that says “Surface.” Click the “check box” that says “Electron Density.” Two grayish spheres should show up with a key showing electron density at the bottom. Using the electron density diagrams for these elements, explain the origin of the attractive forces that exist between the molecules. Why should they be greater for F2 than for H2? 4) Using the above table, Plot a graph of boiling pt. vs. number of electrons for these diatomic elements. What general relationship appears to exist between b. p. and number of electrons? Is this consistent with your answer to #3? 5) Charged objects exert forces on one another. Describe the distinction chemists make between attractions (discussed in #3) and chemical bonds (discussed in the last unit). 6) Examine the electron density map for methane CH4. Why is this molecule described as non-polar?

7) Describe the trend between boiling pt and number of electrons for the class of hydrocarbons called alkanes, CnH2n+2. Account for this trend in terms of your answers to questions 2 and 6.

alkane boiling pt. (K)

CH4 111

C2H6 187

C3H8 231

C4H10

272

C5H12

309

C6H14

342

Now click on the tab that says “Real Molecules.” There are a number of molecules that we will continually refer to in biology. Out of that list oxygen, carbon dioxide and water. 8) Click on each three and look at them. If these do not allow you to access them, please look up the molecules on your own. Which have bond dipoles? Which have molecular dipoles? Which do you think are polar/nonpolar? Why are they polar/nonpolar? 9) If I had two water molecules near each other do you think they would interact? Would there be any intermolecular forces? If yes why? Draw what this interaction may look like. Use the PhET simulation (that’s the name of the simulator you’ve been using) molecular-polarity to help you answer the following Be sure to refer to diagrams to support your explanations. 10) Under the Real Molecules tab, view the electron density diagram for HF. How does it differ from the one for F2? 11) Examine the diagrams for HF and H2O. Explain why the distribution of electron density for molecules like HF and H2O is not symmetrical. What is meant by the term “electronegativity”? 12) Use the electrostatic potential diagrams for HF and H2O to explain why these molecules are said to be polar. How does this representation help explain the stronger attractions between these molecules? 13) How does the polar nature of water explain how ionic substances dissolve in water? 14) Were it not for hydrogen-bonding, in what phase would water exist on our planet? Explain.

15) How do hydrogen bonds differ from dipole-dipole attractions? Why are hydrogen bonds called “bonds”, rather than attractions? 16) Describe the role hydrogen bonding plays in the structure of ice. Why is ice less dense than liquid water? Draw water molecules in the liquid phase and then in the solid phase to support your explanation. 17) Transpiration is the name given to how water travels up a plant, from its roots to its leaves. Discuss how this happens in the context of water’s special properties. 18) Both ethanol, CH3CH2OH and dimethyl ether, CH3OCH3 have the same molecular formula, but one of these substances has a much higher b.p. than the other. Predict which has the higher b.p. and explain. Lookup and compare the diagrams of each molecule to support your explanation. 19) What is pH? What does the pH scale represent? How do you calculate pH? 20) Why is pH important to the functioning of biological systems?  

Graphing Exercise Data Presentation Objectives After completing this exercise, you should be able to 1. Explain the difference between discrete and continuous variables and give examples. 2. Use one given data set to construct a line graph. 3. Use another given data set to construct a bar graph. 4. Given a set of data, describe how it would best be presented. Activity A: Tables A student team performed the experiment. They tested the pulse and blood pressure of basketball players and nonathletes to compare cardiovascular fitness. They recorded the following data:

Nonathletes Basketball Players

Resting pulse After exercise

Resting pulse After exercise

Trial Trial Trial Trial

Subject 1 2 3 1 2 3 Subject 1 2 3 1 2 3

1 72 68 71 145 152 139 1 67 71 70 136 133 134

2 65 63 72 142 144 158 2 73 71 70 141 144 142

3 63 68 70 140 147 144 3 72 74 73 152 146 149

4 70 72 72 133 134 145 4 75 70 72 156 151 151

5 75 76 77 149 152 153 5 78 72 76 156 150 155

6 75 75 71 154 148 . 147 6 74 75 75 149 146 146

7 71 68 73 142 145 150 7 68 69 69 132 140 136

8 68 70 66 135 137 135 8 70 71 70 151 148 146

9 78 75 80 160 155 153 9 73 77 76 138 152 147

10 73 75 74 142 146 140 10 72 68 64 153 155 155

If the data were presented to readers like this, they would see just lists of numbers and would have difficulty discovering any meaning in them. This is called raw data. It shows the data the team collected without any kind of summarization. Since the students had each subject perform the test three times, the data for each subject can be averaged. The other raw data sets obtained in the experiment would be treated in the same way.

Table. Average Pulse Rate for Each Subject (Average of 3 trials for each subject; pulse taken before and after 5-min step test)

Nonathletes Basketball Players

Resting pulse

After exercise Resting

pulse After

exercise

Subject Average Average Subject Average Average

1 70 145 1 70 134

2 67 148 2 70 142

3 67 144 3 73 149

4 71 139 4 72 151

5 76 151 5 76 155

6 74 150 6 75 146

7 71 146 7 69 136

8 68 136 8 70 146

9 78 156 9 76 147

10 74 143 10 68 155

These rough data tables are still rather unwieldy and hard to interpret. A summary table could be used to convey the overall averages for each part of the experiment. For example: Table. Overall Averages of Pulse Rate (10 subjects in each group; 3 trials for-each subject; pulse taken before and after 5-min step test)

Pulse Rate (beats/min)

Before exercise

After exercise

Nonathletes 71.6 145.8

Basketball players 71.9 146.1

Notice that the table has a title above it that describes its contents, including the experimental conditions and the number of subjects and replications that were used to calculate the averages. In the table itself, the units of the dependent variable (pulse rate) are given and the independent variable (nonathletes and basketball players) is written on the left side of the table. Tables should be used to present results that have relatively few, data points. Tables are also useful to display several dependent-variables at the same time. For example, average pulse rate before and after exercise, average blood pressure before and after exercise, and recovery time could all be put in one table.

Activity B: Graphs Numerical results of an experiment are often presented in a graph rather than a table. A graph is literally a picture of the results, so a graph can often be more easily interpreted than a table. Generally, the independent variable is graphed on the x-axis (horizontal axis) and the dependent variable is graphed on the y-axis (vertical axis). In looking at a graph, then, the effect that the independent variable has on the dependent variable can be determined.

When you are drawing a graph, keep in mind that your objective is to show the data in the clearest, most readable form possible. In order to achieve this, you should observe the following rules:

● Use graph paper to plot the values accurately ● Plot the independent variable on the x-axis and the dependent variable on the y-axis. For example, if you are

graphing the effect of the amount of fertilizer on peanut weight, the amount of fertilizer is plotted on the x-axis and peanut weight is plotted on the y-axis.

● Label each axis with the name of the variable and specify the units used to measure it. For example, the x-axis might be labeled "Fertilizer applied (g/100 m2)"' and the y-axis might be labeled "Weight of peanuts per plant (grams)."

● The intervals labeled on each axis should be appropriate for the range of data so that most of the area of the graph can be used. For example, if the highest data point is 47, the highest value labeled on the axis might be 50. If you labeled intervals on up to 100, there would be a large unused area of the graph.

● The intervals that are labeled on the graph should be evenly spaced. For example, if the values range from 0 to 50, you might label the axis at 0, 10, 20, 30, 40, and 50. It would be confusing to have labels that correspond to the actual data points (for example, 2, 17, 24, 30, 42, and 47).

● The graph should have a title that, like the title of a table, describes the experimental conditions that produced the data.

Figure 2.6 illustrates a well-executed graph

The most commonly used forms of graphs are line graphs and bar graphs.

*While this assignment does not give any examples of Pie Charts, they are also very useful tools for presenting data that represents percentages or relative amounts of something. They are not considered graphs because they do not plot independent and dependent variables against each other. The choice of graph type depends on the nature of the independent variable being graphed. Continuous variables are those that have an unlimited number of values between points. Line graphs are used to represent continuous data. For instance, time is a continuous variable over which things such as growth will vary. Although the units on the axis can be minutes, hours, days, months, or even years, values can be placed in between any two values. Amount of fertilizer can also be a continuous variable. Although the intervals labeled on the x-axis are 0, 200, 400, 600, 800, and 1000 (g/100 m2), many other values can be listed between each two intervals. In a line graph, data are plotted as separate points on the axes, and the points are connected to each other. Notice in Figure 2.7 that when there is more than one set of data on a graph, it is necessary to provide a key indicating which line corresponds to which data set.

Discrete variables, on the other hand, have a limited number of possible values, and no values can fall between them. For example, the type of fertilizer is a discrete variable: There are a certain number of types which are distinct from each other. If fertilizer type is the independent variable displayed on the x-axis, there is no continuity between the values. Bar graphs, as shown in Figure 2.8, are used to display discrete data.

In this example, before- and after-exercise data are discrete: There is no possibility of intermediate values. The subjects used (basketball players and nonathletes) also are a discrete variable (a person belongs to one group or the other).

1) What is the difference between the two graphs (figures 2.8 and 2.9)? 2) Which way would be better to convey the results of the experiment (in references to figures 2.7-2.9)? Explain why. 3) What can you infer from these results?

Activity C: Graphing Practice Use the temperature and precipitation data provided in Table 2.6 to complete the following questions:

1) Compare monthly temperatures in Fairbanks with temperatures in San Salvador. Can data for both cities be plotted on the same graph? What will go on the x-axis? How should the x-axis be labeled? What should go on the y-axis? What is the range of values on the temperature axis? How should this axis be labeled? What is the range of values on the precipitation axis? How should this axis be labeled? What type of graph should be used?

Interpreting Information on a Graph

Objective After completing this exercise, you should be able to 1. Interpret graphs. Once you understand how graphs are constructed, it is easier to get information from the graphs in your textbook as well as to interpret the results you obtain from laboratory experiments. For the graphs below answer the questions that follow.

1) Interpret this graph: What patterns or trends to you see?

2) What was the world's population in 1900? 3) Predict the world's population in 2000. 4) Why does this graph change from a solid line to a dashed line at the end?

* Remember that Rate = amount / time. In this case it should be product / minute.

5) Interpret this graph: What patterns or trends to you see? 6) At what temperature is reaction rate the highest? 7) Can you explain why this is not a “bell curve” with different patterns on each side of the apex?

Please note that the y-axis is given as a “range” of temperatures, not actual temperatures. 8) Interpret this graph: What patterns or trends do you see? 9) At what latitude does the least variation in temperature occur? 10) Miami is at approximately 26° N latitude. From the information on the graph, what is the range in mean monthly temperature there? 11) Minneapolis is at approximately 45° N latitude. From the information on the graph, what is the range in mean monthly temperature there? 12) Sydney, Australia is at approximately 33 ° S latitude. From the information on the graph, what is the range in mean monthly temperature there? 13) Look at any map or photographs of the world to try and explain the temperature patterns in the graph. Hint: think H-bonds.

Please note that the y-axis has no “units” Absorbance is a type of measurement used in spectroscopy. 14) Interpret this graph: What patterns or trends to you see?

15) At what wavelengths does Pr phytochrome absorb the most light? 16) At what wavelengths does Pfr phytochrome absorb the most light? 17) Use this graph to explain why (how) the pigments were named.

18) Interpret these graphs: What patterns or trends to you see? 19) On what day does Paramecium aurelia reach its maximum population density? 20) Does Paramecium caudatum do better when it is grown alone or when it is grown in a mixture with Paramecium aurelia?

Questions for Review Convert the following measures. In biology we frequently use the measurements micro (µ) and nano (n) when discussing cells. 2.8 mm = nm 4.67 m = µm 1.3 nm = µm 67 cm = m 12 µg = ng 1.6 g = kg 300 µg = g 250 mg = µg 83 mL = L 250 mL = L 175 µL = mL 0.5 L = mL 75 oF = °C 50 °c = oF

*In the following questions you will be constructing graphs without plotting data. By practicing how to construct graphs, you will learn how to graph your own data in later labs. Use the regularity and size intervals to determine if a variable is continuous or discrete.

1) A team of students hypothesizes that the amount of alcohol produced in fermentation depends on the amount of sugar supplied to the yeast. They want to use 5, 10, 15, 20, 25, and 30% sugar solutions. They propose to run each experiment at 40°C with 5 mL of yeast. What type of graph is appropriate for presenting these data? Explain why. Sketch the axes of a graph that would present these data. Mark the intervals on the x-axis and label both axes completely. Write a title for the graph.

2) Having learned that the optimum sugar concentration is 25%, the students next decide to investigate whether different strains of yeast produce different amounts of alcohol. If you were going to graph the data from this experiment, what type of graph would be used? Explain why.

Sketch and label the axes for this graph and write a title.

3) A team of students wants to study the effect of temperature on bacterial growth. They put the dishes in different places: an incubator (37°C), a lab room (21°C), a refrigerator (10°C) and a freezer (0°C). Bacterial growth is measured by estimating the percentage of each dish that is covered by bacteria at the end of a 3-day growth period. What type of graph would be used to present these data? Explain why Sketch the axes below. Mark the intervals on the x-axis, and label both axes completely. Write a title for the graph.

4) A team of scientists is testing a new drug, XYZ, on AIDS patients. The scientists monitor patients in the study for symptoms of 12 different diseases. What would be the best way for them to present these data?

Explain why

5) A group of students decides to investigate the loss of chlorophyll in autumn leaves. They collect green leaves and leaves that have turned color from sugar maple, sweet gum, beech, and aspen trees. Each leaf is subjected to an analysis to determine how many mg of chlorophyll is present. What type of graph would be most appropriate for presenting the results of this experiment? Explain why Other necessary review material: Please make sure you have reviewed the biochemicals necessary for life and the function and structure of each. Know all Organelles within a cell and the structure and function of each. Know the characteristics of life and the levels of organization.