Week 1 discussion
Before responding to this discussion, please read the
Scientific Method Tutorial and if needed review optional readings.
Describe an example of how you use the scientific method in
your daily life. Which observation(s) lead you to use the scientific method?
State a good hypothesis, how you are testing the hypothesis (the experiment),
results and conclusion. What are the control and treatment groups in your
experiment? What is the dependent and independent variables in your experiment?
Name at least one controlled variable.
Your main response should be a minimum of 150 words (more is
OK). You must also post a minimum of two significant responses to classmates
that contribute to their learning. The replies should also contain at least 150
words. A reference (or references) should also be included to indicate the
source of information you present.
In you replies please provide suggestions for how the other
students' scientific method examples can be improved. Examples: How can the
hypothesis be edited to make it more specific (better)? Is a proper control
group included? Are the independent, dependent and controlled variables
correctly identified? How can the experimental design be improved? Also
consider sharing any useful videos, tutorials or web-sites that helped you
better understand the scientific method.
Week 2 discussion
Before preparing your response to this week's discussion
topic please watch this video, a crash course in biological molecules:
Consider reviewing the information about proteins,
carbohydrates and fats in the OLI modules.
Pick a type of food that you enjoy. Before you start
researching, state a hypothesis about the nutritional content of this food.
Remember a hypothesis is an educated guess (and may be wrong), and a good
hypothesis is specific.
Then summarize what you learned from your research. Include
an image of at least one molecule found in this food and briefly describe that
molecule in terms of the atoms it is made of and potentially the chemical bonds
that keep the atoms together. Is this a beneficial molecule to consume? Explain
why. Did your research support your hypothesis?
Your main response should be a minimum of 150 words. You
also need to post at least two replies to classmates that contribute to their
learning (also 150 words minimum). Suggest improvements of hypothesis, ask
critical questions or provide additional information that relate to their topic
in your reply. Don't forget to include a reference or references to show the
source of information presented.
Week 3 discussion
Please watch the videos found at
https://www.youtube.com/watch?v=gFuEo2ccTPA and
https://www.youtube.com/watch?v=URUJD5NEXC8. You will need to go to YouTube to
watch the second video, as its author has restricted the ability to embed it in
other content. That video provides an introduction to terminology used to
describe cell types and cell components, and different types of cells:
Even though the basic composition of most cells are similar,
there are many different types of specialized cells found as single-cell
organisms and in in various multi-cell organisms.
In your main post for this discussion you are to describe
the theory of endosymbiosis as proposed by Lynn Margulis; (1) describe the
theory in general terms; (2) describe what chloroplasts and mitochondria
produce in eukaryotic cells (the specific chemical that is produced by electron
transport systems in both cases), (3) provide three details from cell biology
that support the theory.
You main response should be at least 150 words and include
references to all information sources used.
You also need to post at least two 150+ word replies to the
posts of other students. Ask thought-provoking questions and/or provide
additional information.
Week 4 discussion
In lab 4 you are exploring two enzymes, catalase that breaks
down hydrogen peroxide into water and oxygen, and amylase that aids in starch
digestion. These are two examples of the many enzymes found inside our bodies,
and many thousands (possibly millions) of similar and very different enzymes
are found throughout all living organisms.
Enzymes are also used in many of the products we use. Check
your cleaning supplies at home, do any of them list enzymes on the ingredient
list? If so, does it say which type of enzyme? If not, complete online research
to find examples of cleaning products that do contain enzymes. Are there any
other products you use that contain enzymes? What type of enzymes are used in
industry? Which enzymes are found in the food we eat?
After doing some research, choose and describe one enzyme
that is used in cleaning products, other products, industrial procedures or
that is found in food.
(1) Explain how this enzyme is used.
(2) What is the substrate in the chemical reaction catalyzed
by your enzyme?
(3) And what are the product(s)?
Remember that a chemical reaction catalyzed by an enzyme
converts one or more substrates to one or more products, and that most enzymes
are substrate specific. When looking for enzymes remember that their names end
with -ase.
You main response should be at least 150 words and include
references to all information sources used.
You also need to post at least two 150+ word replies to the
posts of other students. As part of your reply search for and share a video,
tutorial or web-site that helps you and your classmates' better understand
enzymes.
Week 5 discussion
As you prepare the outline for the final applied lab project
this week share with the other students what type of experiment you plan to do.
Do not post your entire outline, just include a brief description of the type
of enzyme you plan to use, how you will measure enzyme activity and what type
of treatments you will use to make sure that the presence or absence of an
acidic fluid is your independent variable. You may also post your hypothesis to
get feedback.
In your replies to the other students (two are required),
help them improve their hypothesis and experimental design, point out any
aspects of their plan that may not meet the requirements outlined in the
assignment description, ask questions about their controls, sample size,
details in experimental designs etc.
I will NOT participate in this discussion but rather wait to
provide feedback until after you have submitted your outlines. The purpose is
for you to assist each other as you plan your project and prepare the outline.
You can still ask me questions about the outline/final lab project in the
"Ask the Professor" discussion area
Keep in mind that the other students may be wrong, so use
critical thinking and your own judgement. You are responsible for your outline
and final project and I do expect to see individual and original work from
everyone. You can not submit identical outlines that you have created in
collaboration with other students (and certainly not copied from other
students).
Week 6 discussion
This week you are to discuss the Galapagos Islands and
evolutionary biology in four parts:
(1) What is it about the geography and the geology of the
Galapagos Islands that make them an ideal place to stimulate ideas about
evolution in someone like Charles Darwin?
(2) Describe the preparation (academic studies AND practical
experience) of Darwin that allowed him to recognize important characteristics
that linked populations of animals he studied in the Galapagos Islands to
specific niches in their respective environments.
(3) Contrast Darwin's ideas about how populations of
organisms can change over time with the ideas of Jean-Baptiste Lamarck.
(4) Pick an interesting creature found only in the Galapagos
Islands, provide a photo (giving full credit to the source of the photo), and
describe the special adaptations of the animal that allow it to survive in the
ecosystem where it is naturally found.
(5) Are there any other species in the Galapagos Islands
that evolutionary biologists identify as being related to your favorite
creature? Whether there are or aren't, what is thought to be the evolutionary
ancestor for the species you picked?
Important hint regarding the pertinent geology: how did the
Galapagos Islands form, and how did this mechanism of formation create
conditions that would lead to divergent populations of organisms that appear to
have descended from a single species? Learn about the geography of the islands
and figure out how their location interacts with how they were formed to cause
the few species that could arrive there to adapt and specialize into a number
of new species over time.
As always, your main post should contain a minimum of 150
words and two substantial response posts are also needed. Don't forget a
reference (or references).
Lab 1: Introduction
to Science
INSTRUCTIONS:
• On your
own and without assistance, complete this Lab 1 Answer Sheet electronically and
submit it via the Assignments Folder by the date listed in the Course Schedule
(under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save your
Lab 1 Answer Sheet in the following format:
LastName_Lab1 (e.g., Smith_Lab1).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format
(.rtf) file for best compatibility.
Exercise 1: Data Interpretation
Dissolved oxygen is oxygen that is trapped in a fluid, such
as water. Since many living organism requires oxygen to survive, it is a
necessary component of water systems such as streams, lakes and rivers in order
to support aquatic life. The dissolved oxygen is measured in units of ppm
(parts per million). Examine the data in Table 4 showing the amount of
dissolved oxygen present and the number of fish observed in the body of water
the sample was taken from; finally, answer the questions below.
Post-Lab Questions
1.
What patterns do you observe based on the
information in Table 4?
2.
Develop a hypothesis relating to the amount of
dissolved oxygen measured in the water sample and the number of fish observed
in the body of water.
3.
What
would your experimental approach be to test this hypothesis?
4.
What
would be the independent and dependent variables?
5.
What
would be your control?
6.
What
type of graph would be appropriate for this data set? Why?
7.
Graph
the data from Table 4: Water Quality vs. Fish Population
8.
Interpret
the data from the graph made in Question 7
Exercise 2: Experimental Variables
Determine the variables tested in the each of the following
experiments. If applicable, determine and identify any positive or negative
controls.
Observations
1.
A study is being done to test the effects of habitat
space on the size of fish populations. Different sized aquariums are set up
with six goldfish in each one. Over a period of six months, the fish are fed
the same type and amount of food. The aquariums are equally maintained and
cleaned throughout the experiment. The temperature of the water is kept
constant. At the end of the experiment the number of surviving fish is
surveyed.
A.
Independent Variable:
B.
Dependent
Variable:
C.
Controlled
Variables/Constants:
2.
To determine if the type of agar affects
bacterial growth, a scientist cultures E. coli on four different types of agar.
Five petri dishes are set up to collect results:
One with E. coli and type of
nutrient agar and
One with E. coli and type of
mannitol-salt agar
One with E. coli and type of
MacConkey agar
One with E. coli and type of LB
agar
One with type of nutrient agar
without E. coli
All of the petri dishes received the same
volume of agar, and were the same shape and size. During the experiment, the
temperature at which the petri dishes were stored, and at the air quality
remained the same. After one week the amount of bacterial growth was measured.
A.
Independent Variable:
B.
Dependent
Variable:
C.
Controlled
Variables/Constants:
D.
Experimental
Controls/Control Groups:
Exercise 3: Testable
Observations
Determine which of the following observations (1-6) are
testable. For those that are testable answer the following questions:
Determine if the observation is qualitative or quantitative
Write a hypothesis and null hypothesis
What would be your experimental approach?
What are the dependent and independent variables?
What are your controls - both positive and negative?
How will you collect your data?
How will you present your data (charts, graphs, types)?
How will you analyze your data?
Observations
1.
The observation was on the growth of a plant as
per there placement, hence it has been observed that when the plant kept on a
window sill it grows at a faster rate of three inches as compared to when it is
kept on a coffee table in the middle of the living room.
2.
The teller at the bank with brown hair and brown
eyes is taller than the other tellers.
3.
When Sally eats healthy foods, her blood
pressure is 10 points lower than when she eats fatty foods.
4.
The Italian restaurant across the street closes
at 9 pm but the one two blocks away closes at 10 pm.
5.
For the past two days, the clouds have come out
at 3 pm and it has started raining at 3:15 pm
6.
George did not sleep at all the night following
the start of daylight savings.
Exercise 4: Conversion
For each of the following,
convert each value into the designated units.
1. 46,756,790 mg = _______ kg
2. 5.6 hours = ________ seconds
3. 13.5 cm = ________ inches
4. 47 °C = _______ °F
Lab 2: The Chemistry of Life
Pre-Lab Questions
1. Nitrogen fixation is a natural process by which inert or
unreactive forms of nitrogen are transformed into usable nitrogen. Why is this
process important to life?
2. Given what you have learned about the hydrogen bonding shared
between nucleic acids in DNA, which pair is more stable under increasing heat:
adenine and thymine, or cytosine and guanine? Explain why.
3. Which of the following is not an organic molecule; Methane (CH4),
Fructose(C6H12O6), Rosanne (C20H36), or Ammonia (NH3)? How do you know?
?
Experiment 1: Testing for
Proteins
Data Tables and Post-Lab
Assessment
Table 1: A Priori Predictions
Sample Initial Color Final
Color Is Protein Present?
1. Albumin Solution Extremely Pale Yellow Yellowish purple. Yes
2. Gelatin Solution Light almost clear yellow Lavender Yes
3. Glucose Clear Clear Blue No
4. Water Clear Clear Blue No
5. Unknown Milky White Cloudy
sky blue No
Sample Initial Color Final
Color Is Protein Present?
1. Albumin Solution Yellow/Clear Purple Yes
2. Gelatin Solution Yellow/Clear Purple Yes
3. Glucose Clear Bluish Clear No
4. Water Clear Bluish Clear No
5. Unknown Cloudy Cloudy
sky blue No
Table 2: Testing for Proteins
Results
Take a picture of your results.
Include a note with your name and date on an index card in the picture. Insert
picture here:
BEFORE AFTER
1
– CLEAR-YELLOW PURPLE
2
– YELLOWISH/CLEAR PURPLE
3
– CLEAR CLEAR
4
– CLEAR CLEAR
5
– CLOUDY CLOUDY
Post-Lab Questions
1. Write a statement to explain the molecular composition of the
unknown solution based on the results obtained during testing with each
reagent.
2. How did your a priori predictions from Table 1 compare to your
actual results in Table 2? If there were any inconsistencies, explain why this
occurred.
3. Identify the positive and negative controls used in this
experiment. Explain how each of these controls are used, and why they are
necessary to validate the experimental results.
4. Identify two regions which proteins are vital components in the
human body. Why are they important to these regions?
5. Diet and nutrition are closely linked to the study of
biomolecules. Describe one method by which you could monitor your food intake
to ensure the cells in your body have the materials necessary to function.
Experiment 2: Testing for
Reducing Sugars
Data Tables and Post-Lab
Assessment
Table 3: Testing for Reducing
Sugars Results
Sample Initial Color Final
Color
Reducing Sugar Present
1 – Potato Cloudy White Bluish/Greenish Yes
2 – Onion Cloudy Yellow Yellow-Green Yes
3 - Glucose Solution Clear Yellowish Yes
4 – Water Clear Clear Blue No
5 – Unknown Cloudy Cloudy Blue No
Take a picture of your results.
Include a note with your name and date on an index card in the picture. Insert
picture here:
BEFORE AFTER
1
– CLOUDY-WHITE BLUEISH
2
– CLOUDY-YELLOW YELLOWISH-GREEN
3
– CLEAR CLEAR BLUE
4
– CLEAR CLEAR BLUE
5
– CLOUDY CLOUDY BLUE
Post-Lab Questions
1. What can you conclude about the molecular make-up of potatoes and
onions based on the two tests you performed? Why might these foods contain
these substance(s)?
2. What results would you expect if you tested ribose, a
monosaccharide, with Benedict’s solution? Biuret solution?
Experiment 3: What Household
Substances are Acidic or Basic?
Data Tables and Post-Lab
Assessment
Table 4: pH Values of Common
Household Substances
|
Substance
|
pH Prediction
|
Test Strip Color and pH
|
|
Acetic Acid (Vinegar)
|
1
|
4
|
|
Sodium Bicarbonate Solution (Baking Soda)
|
10
|
8
|
|
Dish Soap
|
14
|
4
|
|
Fabuloso
|
5
|
5
|
|
Cranberry Juice
|
12
|
3
|
|
Milk
|
11
|
6
|
Take a picture of your results.
Include a note with your name and date on an index card in the picture. Insert
picture here:
Post-Lab Questions
1. What is the purpose of determining the pH of the acetic acid and
the sodium bicarbonate solution before testing the other household substances?
2. Compare and contrast acids and bases in terms of their H+ ion and
OH- ion concentrations.
3. Name two acids and two bases you often use.
Lab 3: Cell Structure
and Function
INSTRUCTIONS:
• On
your own and without assistance, complete this Lab 3Answer Sheet electronically
and submit it via the Assignments Folder by the date listed intheCourse
Schedule (under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save
your Lab 3Answer Sheet in the following format:
LastName_Lab3 (e.g., Smith_Lab3).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format
(.rtf) file for best compatibility.
Pre-Lab Questions
1. Identify three major similarities and differences between
prokaryotic and eukaryotic cells.
2. Where is the DNA housed in a prokaryotic cell? Where is it housed
in a eukaryotic cell?
3. Identify three structures which provide support and protection in
a eukaryotic cell.
Experiment 1: Cell Structure and
Function
Label each of the arrows in the
following slide image:
A=Chromosomes
B=Nucleus
C=Cell wall
D=Cytoplasm
Post-Lab Questions
1. What is the difference between the rough and smooth endoplasmic
reticulum?
2. Would an animal cell be able to survive without mitochondria? Why
or why not?
3. What could you determine about a specimen if you observed a slide
image showing the specimen with a cell wall, but no nucleus or mitochondria?
4. Hypothesize why parts of a plant, such as the leaves, are green,
but other parts, such as the roots, are not. Use scientific reasoning to
support your hypothesis.
Experiment 2: Osmosis - Direction
and Concentration Gradients
Data Tables and Post-Lab
Assessment
Table 3: Sucrose Concentration
vs. Tubing Permeability
Table 3: Sucrose Concentration
vs. Tubing Permeability
Band Color % Sucrose in Beaker %
Sucrose in Bag Initial Volume
(mL) Final Volume (mL) Net Displacement (mL)
Yellow 3 30 10
30 30
Red 3 15 10
25 25
Blue 3 3
10 15 15
Green 30 3 10 10 10
Hypothesis:
When dialysis tubing containing
less sucrose concentration is placed in a beaker of water, the volumeof the
contents in dialysis tubing increases.
Post-Lab Questions
1. For each of the tubing pieces, identify whether the solution
inside was hypotonic, hypertonic, or isotonic in comparison to the beaker
solution in which it was placed.
2. Which tubing increased the most in volume? Explain why this
happened.
3. What do the results of this experiment this tell you about the
relative tonicity between the contents of the tubing and the solution in the
beaker?
4. What would happen if the tubing with the yellow band was placed
in a beaker of distilled water?
5. How are excess salts that accumulate in cells transferred to the
blood stream so they can be removed from the body? Be sure to explain how this
process works in terms of tonicity.
6. If you wanted water to flow out of a tubing piece filled with a
50% solution, what would the minimum concentration of the beaker solution need
to be? Explain your answer using scientific evidence.
7. How is this experiment similar to the way a cell membrane works
in the body? How is it different? Be specific with your response.
Lab 4: Enzymes
INSTRUCTIONS:
• On
your own and without assistance, complete this Lab 4Answer Sheet electronically
and submit it via the Assignments Folder by the date listed intheCourse
Schedule (under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save
your Lab 4Answer Sheet in the following format:
LastName_Lab4 (e.g., Smith_Lab4).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format
(.rtf) file for best compatibility.
Pre-Lab Questions
1. How could you test to see if an enzyme was completely saturated
during an experiment?
2. List three conditions that would
alter the activity of an enzyme. Be specific with your explanation.
3.Take a look around your house
and identify household products that work by means of an enzyme. Name the
products, and indicate how you know they work with an enzyme.
Experiment 1: Enzymes in Food
Data Tables and Post-Lab
Assessment
Table 1: Substance vs. Starch
Presence
Table 1: Substance vs. Starch
Presence
Substance Resulting Color Presence of
Starch?
Positive Control: Ginger Root Yellow No
Negative Control: Distilled Water Yellow/Brown No
Food Product: Bread Blue/Black Yes
Food Product: Potato chips Blue/Black
Yes
Saliva: Yellow/Brown No
Post-Lab Questions
1. What were your controls for this experiment? What did they
demonstrate? Why was saliva included in this experiment?
2. What is the function of amylase? What does amylase do to starch?
3. Which of the foods that you tested contained amylase? Which did
not? What experimental evidence supports your claim?
4. Saliva does not contain amylase until babies are two months old.
How could this affect an infant’s digestive requirements?
5. There is another digestive enzyme (other than salivary amylase)
that is secreted by the salivary glands. Research to determine what this enzyme
is called. What substrate does it act on? Where in the body does it become
activated, and why?
6. Digestive
enzymes in the gut include proteases, which digest proteins. Why don’t these
enzymes digest the stomach and small intestine, which are partially composed of
protein?
Experiment 2: Effect of
Temperature on Enzyme Activity
Data Tables and Post-Lab
Assessment
Table 2: Balloon Circumference
vs. Temperature
Tube Temperature (°C) Uninflated
Balloon Circumference (cm) Final Balloon
Circumference (cm) Difference in
Balloon Circumference (cm)
1 - (Cold) 8 6
12 6
2 - (RT) 24 16.2 10.2
3 - (Hot) 85 25 19
Post-Lab Questions
1. What reaction is being catalyzed in this experiment?
2. What is the enzyme in this experiment? What is the substrate?
3. What is the independent variable in this experiment? What is the
dependent variable?
4. How does the temperature affect enzyme function? Use evidence
from your data to support your answer.
5. Draw a graph of balloon diameter vs. temperature. What is the
correlation?
6. Is there a negative control in this experiment? If yes, identify
the control. If no, suggest how you could revise the experiment to include a
negative control.
7. In general, how would an increase in substrate alter enzyme
activity? Draw a graph to illustrate this relationship.
8. Design an experiment to determine the optimal temperature for
enzyme function, complete with controls. Where would you find the enzymes for
this experiment? What substrate would you use?
Lab 5: Meiosis
INSTRUCTIONS:
• On
your own and without assistance, complete this Lab 5Answer Sheet electronically
and submit it via the Assignments Folder by the date listed intheCourse
Schedule (under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save
your Lab 5Answer Sheet in the following format:
LastName_Lab5 (e.g., Smith_Lab5).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format
(.rtf) file for best compatibility.
?
Pre-Lab Questions
1. Compare and contrast mitosis and meiosis.
2. What major event occurs during interphase?
Experiment 1: Following
Chromosomal DNA Movement through Meiosis
Data Tables and Post-Lab
Assessment
Trial 1 - Meiotic Division
Without Crossing Over Pipe Cleaners Diagram:
Take pictures of your pipe
cleaners for each phase of meiosis I and II without crossing over. Include
notes with your name, date and meiotic stage on index cards in the pictures.
Please use the lowest resolution possible so that your file does not become too
large to submit.
Insert pictures here:
Trial 2 - Meiotic Division with
Crossing Over Pipe Cleaners Diagram:
Take pictures of your pipe
cleaners for each phase of meiosis I and II with crossing over. Include notes with your name, date and
meiotic stage on index cards in the pictures.
Please use the lowest resolution possible so that your file does not
become too large to submit.
Insert pictures here:
Part 2: Modeling Meiosis with
Crossing Over
Part 2 - Meiotic Division Beads
Diagram:
Post-Lab Questions
1. What is the ploidy of the DNA at the end of meiosis I? What about
at the end of meiosis II?
2. How are meiosis I and meiosis II different?
3. Why do you use non-sister chromatids to demonstrate crossing
over?
4. What combinations of alleles could result from a crossover between
BD and bd chromosomes?
5. How many chromosomes were present when meiosis I started?
6. How many nuclei are present at the end of meiosis II? How many
chromosomes are in each?
7. Identify two ways that meiosis contributes to genetic
recombination.
8. Why is it necessary to reduce the number of chromosomes in
gametes, but not in other cells?
9. Blue whales have 44 chromosomes in every cell. Determine how many
chromosomes you would expect to find in the following:
Sperm
Cell:______________________________
Egg
Cell:________________________________
Daughter Cell before Meiosis
I:______________
Daughter cell from Meiosis
II:____________
10. Research and find a disease that is caused by chromosomal
mutations. When does the mutation occur? What chromosomes are affected? What
are the consequences?
There are many examples of
diseases that are caused by chromosomal mutations. Some of these are
Huntington's disease, Down syndrome, Turner syndrome etc.
11. Diagram what would happen if sexual reproduction took place for
four generations using diploid (2n) cells.
Experiment 2: The Importance of
Cell Cycle Control
For each of the five
abnormalities you find online, copy and paste a picture of it (and be sure to
cite the URL for the picture)—you will not be photographing your own results
for this section of lab, because you’re doing your research online for the
questions below.
Data Tables and Post-Lab
Assessment
1. [paste in your online picture and cite the
URL]
2. [paste in your online picture and cite the
URL]
3. [paste in your online picture and cite the
URL]
4. [paste in your online picture and cite the
URL]
5. [paste in your online picture
and cite the URL]
Post-Lab Questions
1. Record your hypothesis from Step 1 in the Procedure section here.
2. What do your results indicate about cell cycle control?
3. Suppose a person developed a mutation in a somatic cell which
diminishes the performance of the body’s natural cell cycle control proteins.
This mutation resulted in cancer, but was effectively treated with a cocktail
of cancer-fighting techniques. Is it possible for this person’s future children
to inherit this cancer-causing mutation? Be specific when you explain why or
why not.
4. Why do cells which lack cell cycle control exhibit karyotypes
which look physically different than cells with normal cell cycle.
5. What are HeLa cells? Why are HeLa cells appropriate for this
experiment?
Lab 6: Taxonomy
INSTRUCTIONS:
• On
your own and without assistance, complete this Lab 6 Answer Sheet
electronically and submit it via the Assignments Folder by the date listed in
the Course Schedule (under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save
your Lab 6 Answer Sheet in the following format: LastName_Lab6 (e.g., Smith_Lab6).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf)
file for best compatibility.
Pre-Lab Questions
1. Use the following classifications to determine which organism is
least related out of the three. Explain your rationale.
Table 2: Classifications
Classification Level American Green Tree Frog European Fire- Bellied Toad Eastern Newt
Domain Eukarya Eukarya Eukarya
Kingdom Animalia Animalia Animalia
Phylum Chordata Chordata Chordata
Class Amphibia Amphibia Amphibia
Order Anura Anura Caudata
Family Hylidae Bombinatoridae Salamandridae
Genus Tursipops Bombina Notophthalmus
Species cinerea bombina viridescens
2.
3. How has DNA sequencing affected the science of classifying
organisms?
4. You are on vacation and see an organism that you do not
recognize. Discuss what possible steps you can take to classify it.
Exercise 1: Dichotomous Key
Practice
Table 3: Dichotomous Key Results
Organism Binomial Name
I BROAD-TAILED HUMMINGBIRD
SELAPHOROUS PLATYCERCUS
Ii HOUSE MOUSE MUS MUSCULUS
Iii NORTHERN CRANBERRY VACCINIUM OXYCOCCUS
Iv CHANNELL-BILLED TOUCAN RAMPHASTOS VITELLINUS
V WHITE OAK QUERCUS ABIA
Vi MEXICAN REDKNEE TARANTULA EUATHLUS SMITHI
Vii GARDEN SNAIL HELIX ASPERSA
Viii ZEBRA FINCH TAENIOPYGIA GUTTATO
Ix JAPANESE HONEYSUCKLE LONICERA IAPONICA
Xi AMERICAN GOLDFINCH CARDUELIS TRISTIS
Xii EUROPEAN RHINOCEROS BEETLE ORYCTES NASICORNIS
Xiii PILEATED WOODPECKER DRYOCOPUS PILEATUS
I BROAD-TAILED HUMMINGBIRD
SELAPHOROUS PLATYCERCUS
Post-Lab Questions
1. What do you notice about the options of each step as they go from
number one up?
2. How does your answer from Question 1 relate to the Linnaean
classification system?
Exercise 2: Classification of
Organisms
Data Tables and Post-Lab
Assessment
Table 2: Key Characteristics of
Some Organisms
Organism Kingdom
Domain Defined Nucleus Motile Cell Wall Photosynthesis Unicellular
E. coli Yes Yes
Protozoa Yes Yes
Yes
Mushroom Yes Yes
Sunflower Yes Yes Yes
Bear Yes Yes
Figure 4: Exercise 2 -
Classification of Organisms Flow Chart
Post-Lab Questions
1. Did this series of questions correctly organize each organism?
Why or why not?
2. What additional questions would you ask to further categorize the
items within the kingdoms (Hint: think about other organisms in the kingdom and
what makes them different than the examples used here)?
3. What questions would you have asked instead of the ones that you
answered about when classifying the organisms?
Lab 7: Ecological
Interactions
• On
your own and without assistance, complete this Lab 7Answer Sheet electronically
and submit it via the Assignments Folder by the date listed intheCourse
Schedule (under Syllabus).
• To
conduct your laboratory exercises, use the Laboratory Manual located under
Course Content. Read the introduction and the directions for each
exercise/experiment carefully before completing the exercises/experiments and
answering the questions.
• Save
your Lab 7Answer Sheet in the following format:
LastName_Lab7 (e.g., Smith_Lab7).
• You
should submit your document as a Word (.doc or .docx) or Rich Text Format (.rtf)
file for best compatibility.
Pre-Lab Questions
1. Would you expect endangered species to be more frequently
generalists or specialists? Explain your answer.
2. How does temperature affect water availability in an ecosystem?
3. Choose a species and describe some adaptations that species
developed that allow them to survive in their native habitat.
Experiment 1: Effects of pH on
Radish Seed Germination
Data Tables and Post-Lab
Assessment
Table 1: pH and % Radish Seed
Germination
Stage/Day Observations Acetic Acid Sodium Bicarbonate Water
|
Stage/Day
Observations
|
Acetic
Acid
|
Sodium
Bicarbonate
|
Water
|
|
Initial
pH
|
5
|
7
|
6
|
|
Day
1-2
|
Shell
is medium brown in color – all seeds closed
|
Shell
is dark brown in color –All seeds closed
|
5
seeds starting to come out remainder of 5 out of shell- 10
|
|
|
|
|
|
|
Day
3
|
Shell
is medium brown in color – All seeds closed
|
Shell
is dark brown in color –All seeds closed
|
5
seeds out with green leaves – 5 shells out with white fuzzy root
|
|
Day
4
|
Shell
is medium brown in color – All seeds closed
|
Shell
is dark brown close to black in color – All seeds closed
|
All
seeds out of shell and have green leaves - 10
|
|
Day
5
|
Shell
is medium brown in color – All seeds closed
|
Shell
is dark brown close to black in color – All seeds closed
|
All
seeds out and have green leaves – 6 standing up and pushing lid up, remainder
4 forming to stand up
|
|
Day
6
|
Shell
is medium brown in color – All seeds closed
|
Shell
is dark brown in color close to black– All seeds closed
|
All
seeds out and have green leaves – all standing up and lid pushing up.
|
|
Day
7
|
Shell
is medium brown in color – All seeds closed
|
Shell
is dark brown in color close to black – All seeds closed
|
All
seeds out and have green leaves – all standing up and lid pushing up.
|
Post-Lab Questions
1. Compare and construct a line graph based on the data from Table 1
in the space below. Place the day on the x axis, and the number of seeds
germinated on the y axis. Be sure to include a title, label the x and y axes,
and provide a legend describing which line corresponds to each plate (e.g.,
blue = acetic acid, green = sodium bicarbonate, etc…).
2. Was there any noticeable effect on the germination rate of the
radish seeds as a result of the pH? Compare and contrast the growth rate for
the control with the alkaline and acidic solutions
3. According to your results would you say that the radish has a
broad pH tolerance? Why or why not? Use your data to support your answer.
4. Knowing that acid rain has a pH of 2 - 3 would you conclude that
crop species with a narrow soil pH range are in trouble? Explain why, or why
not, using scientific reasoning. Is acid rain a problem for plant species and
crops?
5. Research and briefly describe a real world example about how acid
rain affect plants. Be sure to demonstrate how pH contributes to the outcome,
and proposed solutions (if any). Descriptions should be approximately 2 - 3
paragraphs. Include at least three citations (use APA formatting).
Outline Final Applied Lab Project
Instructions
Include the following in your
outline:
Name of enzyme you will use
Name of organism (if applicable)
The substrate and products in the
chemical reaction
Method for measuring enzyme
activity
Treatment: acidic fluid(s), pH,
length of exposure, how you will treat your samples
The control(s) in the experiment
Hypothesis
How you will present your data
(table and/or type of graph)
Anything else you would like to
get feedback on before you start your experiment
Final Applied Lab Project
Instructions
Final Applied Lab Project (1
credit Lab Component)
Addresses course outcomes 1-4:
recognize and explain how the
scientific method is used to solve problems
make observations and
discriminate between scientific and pseudoscientific explanations
weigh evidence and make decisions
based on strengths and limitations of scientific knowledge and the scientific
method
use knowledge of biological
principles, the scientific method, and appropriate technologies to ask relevant
questions, develop hypotheses, design and conduct experiments, interpret
results, and draw conclusions
This is the culminating lab
assessment in BIOL 102. It is designed to assess your ability to apply the
principles of the scientific method.
The Effect of low pH on Enzyme
Activity
Design an experiment in which you
will test the effect of an acidic fluid on enzymatic activity. Recall: enzymes
are proteins! To complete this project, it may be useful for you to first
review the Scientific Method Tutorial, information about pH and enzymes in the
text book and course modules, Lab 1 (Introduction to Science) and Lab 4
(Enzymes). As you review Lab 4, you will
be reminded that there are several factors that impact enzymatic activity: pH,
temperature, and amount of reagent. It is OK to use the same enzyme/substrate/method
as you did in lab 4 (but modify the treatment), or you can search on-line to
find a different enzyme/substrate/method for measuring enzyme activity for your
project (include all references).
As you design your experiment for
this project, please remember that you are trying to examine how an acidic
fluid will modify the outcome of an enzymatic reaction. To successfully complete this project, you
will need to identify the question(s) being asked in your experiment and the
hypothesis that you are testing. In your
experimental design, you must clearly explain what you are doing. That means
that you will need to identify the enzyme, the substrate, the acidic fluid used
as treatment, the control treatment and the method of measuring enzyme
activity, as well as explain your experimental protocol. You must also thoroughly explain how the
acidic fluid impacted enzyme activity based on the results from your own
experiment as well as knowledge of enzymes and pH from the text book, modules,
lab manual and potentially additional information sources.
Hint: Keep in mind that the acid
will change the environmental conditions of the experiment (for example, a low
pH value could change the shape of the active site on the enzyme protein),
without directly participating in the reaction.
Lab Materials
You may need all or some of the
following, depending on your experimental design:
Materials from your lab ki
pH paper
hydrogen peroxide solution (you
can purchase this at a pharmacy if you have used up the bottle that came with
the lab kit)
plastic beakers or cups
vinegar
yeast (can be purchased at
grocery store if more is needed)
balloons
plastic bottle
marker for labeling of beakers
Cell phone/digital camera -
pictures required
You may choose to use additional
materials (different acidic fluids and/or different organisms and/or different
substrate if you chose an enzyme other than catalase).
Write a lab report that includes
the following:
1. Title page: descriptive title,
your name, course name, semester
2. Introduction: general
background information about enzymes and specific information about your chosen
enzyme, and the question that you are asking (your hypothesis), 35 points.
3. Design an experiment. Provide
a detailed description of the materials and methods used to conduct the
experiment. Identify control and experimental samples, as well as independent
and dependent variables. Also include the methods used for data collection and
analysis, 35 points.
4. Conduct the experiment and
record your results. Take picture(s) of your results. What did you observe?
Present your data in table and/or graph format. Remember to label everything
and include the unit of measure with all numbers, 15 points.
5. Use your knowledge of enzymes
and pH to interpret and discuss your results. It may be necessary for you to
refer to the OLI course modules, lab manual and/or use additional information
resources. What effect does the acidic treatment have on enzyme activity? Did
you get the expected results? Explain.
6. State a specific and accurate
conclusion. Is your hypothesis supported by the results? Looking back, how
could you have improved your experiment?
7. Include a list of references
to all information sources used in APA format, 15 points.
Avoid Plagiarism
As with all of your assigned
work, it is very important to write your report on your final applied lab
project with your own words. If you do copy one or two sentences directly (do
this sparingly), use quotation marks (") around the copied text, followed
by an in-text reference. All information sources need to be included in the
reference list and as in-text references. Plagiarism will be reported to the
proper UMUC authority. Guidance on how to avoid plagiarism can be found here:
https://www.umuc.edu/students/academic-integrity/ai-tutorial/academic-integrity-tutorial.html
Submission
Submit your final applied lab
project in the assignment folder by the due date specified in the course
schedule.
