Biology

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Description Unit 4 homework 2 cooperative assignment pages 4-75 through 4-77 of the 9th edition of the Human Biology: Condensed.
   
   

Select the letter of the most appropriate answer.

  examples include base substitutions and deletions
  person who has one recessive allele for a recessive genetic disorder
  type of DNA used to prepare a DNA profile
  continuing process by which all organisms on earth now share the same genetic code
  genes contain the coded instructions to manufacture __________
  custom genes that can be inserted into other DNA strands
  genes on this chromosome were used to determine the ancestry of Sally Hemings’ descendants
  combined DNA from multiple sources
  genetic analysis used to trace the ancestry of all humans from Africa
  method of cleaning up environmental; pollution with GM organisms
  new genetic editing technology that uses small pieces of RNA to find specific locations in the DNA strand

 
A. Amino Acids
B. Bioremediation
C. Carrier
D. CRISPR
E. Evolution
F. GM Organism(s)
G. Mitochondrial DNA
H. Point Mutation(s)
I. Protein(s)
J. Recombinant DNA
K. Non-Coding DNA
L. Transgene
M. X Chromosome
N. Y Chromosome

 

 

 

Question 2

 A child with the genes for PKU (a recessive disorder that leads to brain damage because proteins aren’t digested properly) is raised to adulthood under a strict low-protein diet that prevents the gene from being activated. He lives a normal life and eventually becomes a father. As a genetic counselor, explain whether the fact that his gene is inactive affects the probability his future children might inherit the PKU allele. Be complete. Explain the reasoning you used to reach your conclusion.

 

Question 3  

When Theodore Conroy left his house to go to work on Tuesday morning, he saw that his car windows were broken and graffiti was painted his vehicle. When the police arrived to investigate, they found blood on the broken glass. Mr. Conroy had a bandage on his right hand. According to his own statement, Mr. Conroy accidentally cut himself at work.

When the police talked to various neighbors to ask if they had seen or heard anything, they were told that Mr. Conroy had a long-standing dispute with his cousin, Sean Williams, and that Mr. Williams might be to blame for the damage. When they visited the Williams’ residence, they noticed Mr. Williams had a bandage on his left hand. When asked about it, he denied the vandalism and said he cut himself trimming bushes in his yard.

Mr. Williams suggested that teenagers were likely to be responsible for the damage. Tracking down several teenagers who had been seen in the neighborhood, it was discovered that David Tucker was present during the time frame the vandalism took place and he had cuts and scrapes on both hands. Mr. Tucker denied the vandalism and told the police he scraped his hands in a skateboard accident. The police obtained warrants for DNA samples from all three men involved for comparison with the blood on the car. Table 4-6 shows the results of the DNA testing. Based on the DNA evidence, should any of the men that were interviewed be considered a suspect for this crime? Explain your answer.

 
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BI101 Unit 6 Experiment

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Monhybrid and Dihybrid Crosses – Introduction

Mendel crossed true-breeding pea plants in order to develop and understanding of how traits are inherited. True-breeding means that if a plant was crossed with itself, it always generated offspring that looked like the parent. Although Mendel didn’t know this at the time, it meant that the parent plant was homozygous or had two copies of the same allele that controlled the appearance of the trait.

Mendel noticed that when he crossed two true-breeding plants exhibiting different versions of a trait (e.g., green and yellow); the offspring (F1) always looked like only one of the parent plants. We know now that the F1 individuals looked like the parent that carried the dominant trait. But what surprised Mendel, was that when he crossed the F1 individuals with each other, the F2 offspring exhibited BOTH traits! Based on this observation, he concluded that the F1 individuals were hybrids, meaning they carried both alleles for a given trait. Only the dominant trait was expressed in the F1 individuals and the recessive trait, although present, was masked.

A monohybrid cross is when you are interested in crossing individuals that vary in only a single trait (e.g., flower color, seed color, stem length). In a dihybrid cross, we are crossing individuals that differ at two traits (e.g., flower color and seed color, flower color and stem length). Obviously, the more traits that vary, the more complex the crosses become!

By examining the distribution of the various traits obtained following different types of crosses, Mendel was able to describe the general pattern of genetic inheritance. Be sure to review the online lecture this unit on Genetics and pp 146-153 in your book before starting these first two exercises.

We will be using the following website for the first exercise. Be sure that you can access it and use it before beginning:

Fly Lab JS (Links to an external site.)

You will need to complete the Tables and answer the questions in the Unit 6 Experiment Answer Sheet for Exercises 1 and 2.

Inheritance of Human Traits – Introduction

Some human traits are controlled by a single gene that has only two alternative alleles. If a characteristic is determined by the dominant allele, one or both parents express that trait and many of the children will as well. Dominant characteristics will most likely be present in every generation, since the expression of these traits requires only one of the dominant alleles in order to be expressed. If the characteristic is determined by the recessive allele, then neither parent may express the trait nor few of the children. This is because two copies of the recessive allele must be present in order for the recessive trait to be expressed. If a trait is X-linked recessive; meaning the gene for the trait is found on the X chromosome, it will be expressed primarily in males.

The application of human genotypes in medicine and genetic counseling is becoming more and more necessary as we discover more about the human genome. Despite our increasing ability to decipher the chromosomes and their genes, an accurate family history remains one of the best sources of information concerning the individual. In this exercise you will determine your genotype for certain characteristics that are controlled by a single gene with two alleles based on your phenotype. We will not be looking at any X-linked traits in this exercise.

Use the information about the traits of interest in the Unit 6 Experiment Answer Sheet to answer the questions found there.

 
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Discussion 1: Maladaptive Responses To Immune Disorders

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Discussion #1

Maladaptive responses to disorders are compensatory mechanisms that ultimately have adverse health effects for patients. For instance, a patient’s allergic reaction to peanuts might lead to anaphylactic shock, or a patient struggling with depression might develop a substance abuse problem. To properly diagnose and treat patients, advanced practice nurses must understand both the pathophysiology of disorders and potential maladaptive responses that some disorders cause.

Consider immune disorders such as HIV, psoriasis, inflammatory bowel disease, and systemic lupus E. What are resulting maladaptive responses for patients with these disorders?

To prepare:

  • Review Chapter 5 and Chapter 7 in the Huether and McCance text. Reflect on the concept of maladaptive responses to disorders.
  • Select two of the following immune disorders: HIV, psoriasis, inflammatory bowel disease, or systemic lupus E (SLE).
  • Identify the pathophysiology of each disorder you selected. Consider the compensatory mechanisms that the disorders trigger. Then compare the resulting maladaptive and physiological responses of the two disorders.
  • Select one of the following factors: genetics, gender, ethnicity, age, or behavior. Reflect on how the factor might impact your selected immune disorders.

Post on or before Day 3 a brief description of the pathophysiology of your selected immune disorders. Explain how the maladaptive and physiological responses of the two disorders differ. Finally, explain how the factor you selected might impact the pathophysiology of each disorder.

 

Has to be no less than 250 words.    Do you have the book

 

Discussion # 2:

Discussion 2: Arthritis

While arthritis impacts nearly 50 million adults in the United States, it is not a disease that is limited to adulthood. Consider the case of Ashley Russell. At the age of 14 months, Ashley was diagnosed with juvenile rheumatoid arthritis. As a baby, her parents noticed that her knee was always swollen and that she often wanted to be carried instead of walking on her own (Cyr, 2012). After seeking medical care, Ashley’s underlying disorder was discovered. Arthritis in children is not uncommon. According to the CDC (2011), an estimated 294,000 children under age 18 have some form of arthritis or rheumatic condition. Due to the prevalence of the disorder in both children and adults, you must understand the pathophysiology and symptoms of arthritis in order to properly diagnose and prescribe treatment.

To prepare:

  • Review Chapter 37 in the Huether and McCance text and Chapter 24 in the McPhee and Hammer text. Identify the pathophysiology of osteoarthritis and rheumatoid arthritis. Consider the similarities and differences of the disorders.
  • Select two of the following patient factors: genetics, gender, ethnicity, age, or behavior. Reflect on how the factors you selected might impact the pathophysiology of the disorders, as well as the diagnosis of and treatment for the disorders.

Post on or before Day 4 a description of the pathophysiology of osteoarthritis and rheumatoid arthritis, including the similarities and differences between the disorders. Then explain how the factors you selected might impact the pathophysiology of the disorders, as well as the diagnosis of treatment for the disorders.

 
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Ethics

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Surname 1

 

Name:

Instructor:

Course:

Date:

The Decline and fall of Enron

The merging of Enron of InterNorth Inc. in Ohama and Natural Gas Co. in Houston in 1985 formed the Enron Company. Following the merging, the company was rebranded to energy trader and supplier by the chief executive officer (CEO). Enron took advantage of the deregulation of energy which allowed companies to predict the future prices of oil. Consequently, Enron flourished and at the end of the 1990s its shares were its shares were worth $90.75. However, by December 2001, the company was declared bankrupt and the shares worth had declined to $0.26. Its fall affected thousands of employees and strongly shook the Wall Street.

Many economists believe that the exposed criminality in Enron that was admissible in the court of law was the cause of the decline and fall of the company. However, the true cause of the fall was selfishness by company management that applied some legally acceptable half-truths including equating value to shareholder value, the view of a man as economic man, the view of the society as a rising tide of prosperity and the view of leadership as heroic.

Worldwide, there has been a belief that every man is ‘economic man’. Through this belief, man has grown to be self-centered obsessed with increasing personal gains at the expense of others. The belief of economic man brings a wedge of distrust into society (Mintzberg, Robert and Kunal 67). Everyone can only do things for themselves and not for the society. This kind of individualism leads to failure since we are living as individuals but in a social setting. Companies must contribute to the development of the society to enhance their development. Disconnecting from the society will lead to their failure as they operate in a social space.

Establishment of the corporations was meant to benefit the society. However, the rhythm has changed to benefit the shareholders disregarding all other stakeholders (Mintzberg, Robert and Kunal 67). Employees bear the greatest pressure in creating the economic performance yet the large share of the profit is divided among the shareholders. Consequently, the employees feel demotivated to work and disconnected to the top management leading to poor productivity. This eventually results in company fall.

In many corporations, the shareholders are passively creating a need for heroic leaders. The chief executives are employed as the representatives of the shareholders, and in return, they are rewarded huge amount of money for the performance on behalf of the entire enterprise. Supporting this act is the assumption that equates the chief executive to the enterprise and deemed responsible for the entire performance (Mintzberg, Robert and Kunal 67). In an attempt to fit the heroic images, the chief executives promise grand results at the expense of the other employees. Heroic leadership leads to disconnection of the top leaders and every other employee. Lose of connection discourages teamwork and self-motivation leading to eventual fall of the corporation.

An effective organization is considered to be lean and mean. It has the meaning that the company should do more with less and should achieve a win-win situation. Simply, it means lower costs, increased productivity, happier customers, and flatter structures (Mintzberg, Robert and Kunal 67). Through the application of the lean and mean principle, many companies have laid off many employees in an attempt to minimize cost while optimizing profit. This has resulted in burned-out managers, disgruntled customers, angry workers, and quality loss. Reduced job security has resulted in a feeling of betrayal among the employees and hence reduced productivity in the long run.

There is a tendency of every individual wanting to prosper in the society. There has been rhetoric by those in high position that everyone prospers in a selfish economy. However, the saying is meant to fuel their selfish motives by the rich at the expense of the poor. Prosperity has to be both economically and socially and cannot be measured by an increase in economic values only (Mintzberg, Robert and Kunal 67). Economic progression coupled with social regression leads to failure of corporations.

The deregulation of energy market became the turning point of the Enron Company. Due to this the company flourished and by 1990 the company had reached its peak. However, this was followed by a drastic fall and by 2002 the company was declared bankruptcy. The fall of Enron caused havoc in the entire Wall Street. Many economists could not understand how such a big company could collapse overnight. However, the failure of the company started soon the company adopted policies that self-centered without considering their sustainability.

 

 

 

 

 

Works Cited

Mintzberg, Henry, Robert Simons, and Kunal Basu. “Beyond selfishness.” MIT Sloan Management Review 44.1 (2002): 67.

 
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Nutrition 6

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This week you learned about micro nutrients that participate in blood cell formation and function. Also, you learned that minerals are vital players in electrolyte and acid/base balance. This forum will build on that knowledge.

Initial Post:  If your last name starts with the following letter, then you will discuss the following topic for your initial post.

First Letter of Last Name

Topic

A through F

Topic 1

G through L

Topic 2

M through R

Topic 3

S through Z

Topic 4

Topic 1:  Healthy People 2020 set a goal that 80% of the people in the U.S. have optimally fluoridated water available in their community. Today, about 72% of Americans have access to optimally fluoridated water.  Do you know if your community water supply is fluoridated? To find the answer, check with your local water department.  Is the water naturally rich in fluoride, or is this mineral added to the water supply? What amount of fluoride is in the drinking water? If it is added to the water supply, how long has this procedure been in operation? If the water does not provide fluoride, how can you obtain sufficient fluoride?

Topic 2:  Claire runs cross country in college.  She knows she needs adequate carbohydrate to keep her body fueled.  Typically, her food intake consists of cheese sticks and a glass of orange juice for breakfast; a peanut butter sandwich, apple , bag of pretzels, and sweetened tea for lunch; spaghetti with marinara sauce, garlic, bread, salad, and a glass of milk for dinner; and an orange for her evening snack.  Lately, she is feeling tired and has to wear a sweatshirt in class to keep warm. She is also having trouble concentrating.  What do you think is causing Claire’s problem and why?  What would you recommend?

Topic 3: Your Uncle has seen the recent recommendations to reduce our salt intake along with the discussions on the amount of salt in our food. He wonders why we need it if it is so bad for our health.  How would you explain this dilemma?  What would you recommend?

Topic 4: Your friend is sick and has diarrhea, maybe from food poisoning.  Why is it important for her to drink water even when she does not feel well and doesn’t want to eat?  Do you think drinking fluids will help her feel better?

Your initial post must be at least 250 words and posted by Wednesday, 11:55 pm EST. You need to state your thesis and support it with evidence and at least one outside, reputable reference. Your textbook is not an outside reference. Remember, there is no right or wrong.  Before you post your initial forum discussion, submit it in the assignment area, so its originality is checked by turnitin.com. Your originality index or score should be less than 15%. If it is greater than 15%, rewrite your discussion, submit it again in the assignment area and check the %. Keep doing this until your % is less than 15 and then post your discussion in the forum.  Please note, it can take 24 hours for the second submission to be checked, and the score returned.  If you do not check your post, then I will take points off.

Follow-up Posts: Once you have posted your initial forum discussion, you must reply to at least two other learner’s post.  Your two follow-up forums must be at least 100 words and posted

 
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Discussion

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Discussion 1: Blue Gold

Read the paragraphs below and respond to the questions.

Environmentalists believe that the world is running out of clean drinking water.  Over 97% of the world’s water is salt water found in the oceans.  Salt water is unsuitable for drinking without expensive desalination.  Of the fresh water in the world, most is locked in frozen form in the polar ice caps and glaciers and therefore unavailable.  This leaves only a small percentage in groundwater, lakes, and rivers that could be available for drinking, industry, and irrigation.  However, some of that water is polluted and unsuitable.

Water has always been the most valuable commodity in the Middle East, even more valuable than oil.  But as fresh water becomes limited and the world’s population grows, the lack of sufficient clean water is becoming a worldwide problem.

The combination of increasing demand and dwindling supply has attracted global corporations who want to sell water.  Water is being called the “blue gold” of the twenty-first century, and an issue has arisen regarding whether the water industry should be privatized.  That is, could water rights be turned over to private companies to deliver clean water and treat wastewater at a profit, similar to the way oil and electricity are handled?  Private companies have the resources to upgrade and modernize water delivery and treatment systems, thereby conserving more water.  However, opponents of this plan claim that water is a basic human right required for life, not a need to be supplied by the private sector.  In addition, a corporation can certainly own the pipelines and treatment facilities, but who owns the rights to the water?  For example, North America’s largest underground aquifer, the Ogallala, covers 175,000 square miles under several states in the southern Great Plains.  If water becomes a commodity, do we allow water to be taken away from people who cannot pay in order to give it to those who can?

Clovis has water concerns as well. Check out the links below for information and feel free to do your own research to bring into the discussion.

https://www.epa.gov/pfas (Links to an external site.)

https://www.epa.gov/ground-water-and-drinking-water/drinking-water-health-advisories-pfoa-and-pfos (Links to an external site.)

https://www.kcbd.com/2019/02/25/cannon-air-force-base-water-contamination-shuts-down-clovis-dairy/ (Links to an external site.)

https://abc7amarillo.com/news/local/air-force-responds-to-questions-surrounding-contaminated-water-in-clovis (Links to an external site.)

https://www.cityofclovis.org/?p=6241 (Links to an external site.)

Questions:

1. Do you agree that the water industry should be privatized?  Why or why not?

2. Is access to clean water a “need” or a “right”?  If it is a right, who pays for that right?

3. Because water is a shared resource, everyone believes they can use water, but few people feel responsible for conserving it.  What can you do to conserve water?

4. Do you think the drinking water in Clovis is safe? Support your answer with evidence. What do you think needs to be done about this situation?

 

Discussion 2: Stem Cells: It’s What For Dinner Read and do questions 1, 2, 3

In August 2013 beef stem cells used to grow hamburger meat were given a public taste test.

Check out the video here:

http://www.today.com/video/today/52675206#52675206 (Links to an external site.)

or here:

http://www.cbsnews.com/news/burger-grown-from-cow-stem-cells-in-laboratory-put-to-taste-test-in-london/

And the article that appeared in the New York Times here:

http://www.nytimes.com/2013/08/06/science/a-lab-grown-burger-gets-a-taste-test.html

Questions:

1. What questions and concerns does this (growing hamburger meat in the lab) raise?

* What are the pros?

* What are the cons?

2. What are some experiments that could be designed based on these issues?

*On a microscopic level?

*On a macroscopic level?

3. What type of data would be the most meaningful to you?

4. Would you eat it? Why or why not?

 

Discussion 3: Gene banks versus privacy invasion

Gene Banks Versus Privacy Invasion

In 1999, the Icelandic parliament passed an act to establish a national gene bank, a large-scale genetic database composed of blood samples from each of its 275,000 citizens. DNA isolated from this blood was to be used as the basis for genetic studies. But lately, privacy concerns have caused Iceland to rethink the project.

Iceland was the first country to create a gene bank, followed by Estonia and then Tonga. Iceland is unique in that it has a fairly homogeneous population in which little immigration occurs, and several natural disasters have contributed to similarities in the population’s gene pool. In addition, the country provides national medical care for its citizens, so it has extensive medical records dating back to 1915. Furthermore, genealogies of many Icelandic families are available for as far back as 500 years.

Concerns arose when Iceland’s parliament decided to sell exclusive rights to all its genetic data and medical and genealogical records to a U.S. company, deCODE Genetics, for the purpose of gene discovery. In turn, deCODE promised to provide any treatments and diagnostic tests developed from this research free of charge to Icelanders for the life of the patient. In a very short time, deCODE signed a $200 million contract with Hoffman LaRoche to search for several common human genetic diseases. So far, several genes have been successfully identified, including a gene linked to osteoarthritis.

Opponents of this agreement felt that it allowed a scientific monopoly on a veritable gold mine of genetic information. But even more seriously, they objected to the gene database on the basis of patient’s rights regarding informed consent and genetic privacy. In the United States, you must give permission to have your samples used for research. In Iceland, everyone would be included in the genetic research unless they “opted out,” although the data were to be encrypted so that no sample could be linked to a particular person. Even though researchers are commonly allowed access to medical databases as long as the data cannot be linked to individual patients, the commercial nature of this data bank and its for-profit research caused some people to feel that individual consent should have been required before the medical records were released to deCODE. In April 2004, Iceland’s Supreme Court ruled that “the 1998 law governing the creation of the database is unconstitutional because it fails to protect personal privacy adequately.”

In addition to gene banks used for scientific and medical purposes and research, the popularity of genetic testing in the private sector is a booming business. Read this article  https://www.marketwatch.com/press-release/dna-testing-is-popular-but-many-are-unaware-of-privacy-concerns-2019-01-02 (Links to an external site.) 

Questions

1. Do you think any for-profit company should have a monopoly or preferred position with regard to genetic databases or medical records? Why or why not?

2. What concerns should the Icelandic citizens now be discussing with their parliament?

3. Should individuals be allowed to “opt-out” of genetic records? How can the rights of children or mentally disabled individuals be protected? Should sensitive information concerning inheritance of a genetic disease be on record? How can privacy be protected while still allowing researchers access to complete genetic data?

4. Have you or would you want to get a genetic test with a private company here in the US to either learn about your families history or possible genetic concerns? What are the major benefits you see in this kind of test (give me at least 3)? What are some major concerns you have with the company having access to your data (give me at least 3)? Do you think the company can protect your data from hackers or that they could be forced to share your data with the government?

 

Discussion 4: What is science and evolution

 

What is science and what is not? This video is a good summary of what is science and what is not, which is a helpful place to start the discussion. Michael Shermer is a skeptic, author and speaker. His TED talk is a little older, but he compares, and contrasts evidence verses belief.

Why people believe weird things | Michael Shermer (Links to an external site.) Why people believe weird things | Michael Shermer Creationism and Evolution

Evolution is a cornerstone theory in which most of biology assumes the mechanisms of evolution and natural selection are the drivers of life on this planet. Misunderstanding of scientific theories and fallacies in logic, as well as impassioned opinions on both sides have lead to a major clash between science and religion when it comes to teaching about the origins of life on earth. Science must be able to use inference from previous scientific studies to make predictions about future scientific studies or predictions about how life will work in a given set of circumstances. The theory of evolution helps us do that.

Here are some videos with popular scientists discussing some aspects of evolution.

What is the Evidence for Evolution? (Links to an external site.) What is the Evidence for Evolution?

Neil Tyson on God Driven Evolution (Links to an external site.) Neil Tyson on God Driven Evolution

Bill Nye Explains Darwin's Theory of Evolution (Links to an external site.) Bill Nye Explains Darwin's Theory of Evolution

Creationism and Evolution

The week before the start of the new semester would be a busy one for Sandra Maxwell. As one of three biology teachers at Irving Community College in Marshall, Alabama, she would have to meet with the entire science department, get her laboratory ready, and review the new textbooks.

Last year the department had gone through the long, tedious adoption procedure that involved reading and rating over fifteen different books. They had narrowed the fifteen down to three, and the community college board picked from those. Sandra really didn’t care which one they had picked; no matter what, she would have to redo her lessons to fit a new book.

There was even more about her new textbook that Sandra didn’t know. The Alabama State Board of Education had adopted an anti-evolution insert to go in all high school and state college biology texts. The insert stated that evolution is a “controversial theory” accepted by “some scientists.” When Sandra saw the insert, she was upset. Could she teach creationism?

Creationism, broadly speaking, is the view that God (the Judeo-Christian God) created the universe, life, and the various kinds of life. Some creationists have sought to undermine the theory of evolution by claiming, for example, that the earth is only 10,000 years old, not 4.5 billion, and that therefore evolution hasn’t had time to occur. They also have argued that DNA could not have developed on its own without the help of an “intelligent agent”-namely, God.

Ever since State v Scopes, the famous Tennessee “Monkey Trial” in 1925 (dramatized in the 1960 film Inherit the Wind), the biology classroom has been the site of a battle pitting science against religion. In the era of the Scopes trial, American fundamentalists had pressed for, and achieved in some states, the passage of anti-evolution laws. More recently, as reported in Science magazine in 1996, creationists have attempted a new strategy: persuading local school boards to give “equal time” in school curricula to alternative theories such as “scientific creationism.” In several states-Ohio and Georgia being two-legislatures are considering bills that will require biology teachers to present “alternative theories” to evolution.

Sandra Maxwell and her fellow biology teachers were confused and unhappy about the situation. As a teacher, Sandra wasn’t sure what to do.

Questions:

1. Can science make claims about how life on earth started? Why or why not? Support your position.

2. Some biology teachers are skipping evolution altogether in order to avoid the controversy. Do you think evolution should be left out of the curriculum? Why or why not?

3. Can biologists make predictions using the idea of creationism? Can biologist make prediction using the theory of evolution? Give an example of a testable hypothesis for either.

4. If you were Sandra, what would you do?

 

Discussion 5: Invasive Species

Killer Seaweed Invades United States

A killer alga has invaded the waters off California. In June 2004, biologists identified a Caulerpa taxifolia mutant as an alien invader in the San Diego area. This alga normally grows in the warm waters of the Caribbean Sea, but it can survive the colder waters of the Pacific Coast, and if not controlled, could spread from California south to Peru.

http://cisr.ucr.edu/images/Caulerpa_01.jpg

Where did this killer come from? As innocent as it seems, it was bred for home aquariums, and then was probably dumped into the water system, where it began to reproduce prolifically. The alga is so adaptive that it can overtake the normal flora of an area, outstripping and outcompeting all other living plants. Currently, 10 patches of the killer alga have been sighted off the California coast, and they are being watched closely by the Southern California Caulerpa Action Team.

The U.S. government has placed this strain of C. taxifolia on the noxious weed list, which means that any possible source of contamination of the weed will be highly restricted. Shipments that contain any type of C. taxifolia and pass through an area where the variety is established, or thought to be established, will be refused entry.

Questions:

1. Do you think this is really that big a deal?

2. Describe another instance in which an introduced species has become a problem for the existing ecosystem – could be in the area in which you live or anywhere else.

 

 

Discussion 6: This topic comes from the “Science in Your Life-Ecology” found on page 630 in the 15th edition of your textbook.

Destruction of Coral Reefs

Coral reefs are among the most biologically diverse and productive communities on Earth. Coral reefs tend to be found in warm, clear, and shallow tropical waters worldwide and are typically formed by reef-building corals, which are cnidarians. Aside from being beautiful and giving shelter to many colorful species of fishes, coral reefs help generate economic income from tourism, protect ocean shores from erosion, and may serve as the source of medicines derived from antimicrobial compounds that reef-dwelling organisms produce.

However, coral reefs around the globe are being destroyed for a variety of reasons, most of them linked to human development. Deforestation, for example, causes tons of soil to settle on the top of coral reef. This sediment prevents photosynthesis of symbiotic algae that provide food for the corals. When the algae die, so do the corals, which then turn white. This is called coral “bleaching”, and it has been seen in the Pacific Ocean and the Caribbean Sea. Evidence suggests that climate change is one of the factors that is leading to coral bleaching and death because corals can tolerate only a narrow range of temperatures. As global temperatures rise, so do water temperatures, and corals can die as a result. Global warming also contributes to favorable conditions for various pathogens that can kill corals, such as those similar to pathogens that cause cholera in humans. Increases in aquatic nutrients from fertilizers that wash into the ocean also make corals more susceptible to diseases, which can also kill them.

https://i1.wp.com/math.ucr.edu/home/baez/ecological/great_barrier_reef_bleaching.jpg

Scientists estimate that 90% of coral reefs in the Philippines are dead or deteriorating due to human activities such as pollution and, especially, overfishing. Fishing methods that employ dynamite or cyanide to kill or stun the fish for food or the pet trade can easily kill corals. Paleobiologist Jeremy Jackson of the Smithsonian Tropical Research Institute in Panama estimates that we may lose 60% of the world’s corals by the year 2050.

Questions

1. What features of coral reefs help explain why they are so biologically important?

2. Considering what is causing the loss of coral reefs, is it possible to save them? How?

Discussion7: Sharks Get a Bad Rap

Sharks Get a Bad Rap

http://dreamstop.com/wp-content/uploads/2016/08/Shark-Dream.jpg

After seeing motion pictures such as Jaws, Deep Blue Sea, and Open Water, many people curb their seaside activities in fear of a vicious shark attack. Indeed, the popular media have depicted the shark as an evil predator of the deep so many times that it takes extra courage to don a snorkel and vest and go to your favorite reef. But despite the shark’s reputation as a terrible killer, only 32 of the approximately 350 shark species have ever been known to attack humans. Sharks attack some 50–75 people each year worldwide, with perhaps 8–12 fatalities—far less than the number of people killed each year by elephants, bees, crocodiles, lightning, or many other natural dangers. Many people lack information about sharks, including their important role in the ocean ecosystem and their many other benefits to humans.

Sharks first appeared about 430 million years ago during the Silurian Period. They are classified in the class Chondrichthyes because their skeleton is made of cartilage. They also have jaws, paired fins, and paired nostrils. Shark habitats can range from shallow coastal areas to deep-water ocean floor habitats and even the open ocean itself. The most important aspect of sharks is their role in the marine ecosystem. As keystone predators, they help control many fish and marine mammal populations, and thus help keep the ecosystem healthy.

In addition, cultures around the world have found that nearly every part of the shark can be used: Its flesh can be eaten; the skin used as leather; the teeth made into jewelry and ornaments; oil extracted from the liver used for high-grade machine oil, vitamin A supplements, and ladies’ cosmetics; and the fins used for shark fin soup and animal treats.

Many parts of the shark have medical value as well. Its cornea has been used in eye surgery (since a shark’s cornea is similar to our own). Shark cartilage can be used to make artificial skin for burn victims. And after a rumor circulated that sharks do not get cancer, it was thought that something in the shark’s system must be a natural tumor suppressor. Thus, cancer researchers have studied sharks to determine why they are resistant to cancer in the hope of applying that information to people someday. In their search, they have settled on cartilage, the substance a shark’s skeleton is made from. Each year, an estimated 100 million sharks are killed for cartilage to be used in health supplements for people seeking alternative cancer cures. As a result, the massive sale of shark cartilage has now exceeded $25 million per year, and certain species have been placed on the international endangered species list.

Questions:

1. What happens if you remove a keystone predator from a community?

2. Would you try a health supplement made from shark cartilage? Why or why not?

3. If sharks are going to be used/studied, how can they be protected so that their ecosystems remain in balance and they are not driven to extinction?

 
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Advanced Biology

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1. Enzymes (30pts).

Embryonic liver tissue contains an enzyme that catalyzes the reaction S→P. Adult liver also displays S→P

activity. Some kinetic data are shown below.

a) (20pts) What conclusion can you draw concerning the identity of the two enzymes?

What is the same or different about them and why might that be. (show all work for full credit)

 

During sever liver damage an enzyme (E1 from above) is released into the blood stream. After severe

exercise a muscle enzyme, Es that catalyzes the same reaction is released into the bloodstream.

Ei and Es can be differentiated easily because they have different Km values The Km of the muscle enzyme

is 2×10-5 M. An assay of the blood sample of a patient gave the results bellow

 

b) (10pts) Is the patient suffering from liver disease or have the simply been exercising two

strenuously, explain your answer (with any plots used for full credit)

 

 

 

 

2. Cell Metabolism (70pts). (refer to the tables at the end of the test to find values for the specific bacteria)

Aerobacter aerogenes is to be cultured aerobically, with glucose (C6H12O6) or pyruvate

(C3H4O3) as the growth substrate. Use the tables below to answer the following questions.

a. Setup (10pts): i) (3pts)Write the general Equation for Biosynthesis

 

 

ii) (3pts) What is the Empirical biomass formula of this species and what is its molecular weight?

 

 

iii) (4pts) What is the biomass degree of reductance of the biomass?

 

b) (15pts) Calculate the biomass yield per mole of glucose (you will need an empirical equation other than YX/S to do so). Show your work for full credit.

 

c) (15pts) Calculate the biomass yield per mole of pyruvate (you will need an empirical equation other than YX/S to do so). Show your work for full credit.

 

 

d) (30pts) i) (10pts)Compare the actual biomass yields per mole glucose or pyruvate to their

respective maximum theoretical yields.

 

ii) (5pts) Which growth substrate is more efficient with respect to biosynthesis?

iii) (10pts) Give two brief explanations why the answer to part a makes sense (or, make an educated guess as to which substrate is more efficient and justify your

answer).

iv) (5pts) Considering the case of growth on glucose, evaluate whether or not one can

expect significant amounts of secreted product(s), why?.

 
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Micro

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Please Pick 2 question to answer from each chapter and provide reference.

2 questions per chapter (chapter 15-20)  10 questions total. Word doc attached.

Chapter 15 

1.Explain the two main features that characterize the third line of host defense mechanisms.

2.Chronic lymphocytic leukemia (CLL) leads to the production of cancerous B cells, and treatment often involves bone marrow transplantation. Based upon your knowledge of lymphocyte development, explain how this procedure can lead to therapeutic effects in some patients.

3.Recently, scientists have been experimenting with using IRA-B cells as a treatment for hospitalized patients in an attempt to prevent them from getting septic infections. Speculate on what the principle behind this might be.

4.Provide an explanation to refute the following statement: Humans would never develop natural immunity to a novel biological agent created in a laboratory.

5.   a.Explain how the anamnestic response is triggered by vaccination. b.Conduct additional research and discuss one current example illustrating how lack of herd immunity within a population has led to localized disease outbreaks in the United States.

Chapter 16

1.Conduct additional research and discuss examples that illustrate how cancer can be both a cause of immune dysfunction and an effect of this process.

2.Summarize the roles of the microbiome and genetics in the development of type I allergic reactions. Discuss how probiotics or gene therapy could be used to alter an individual’s allergic response to antigen.

3.   a.Draw a diagram illustrating whether or not each of the following transfusions would be immunologically compatible. Type A donor into a type B recipient Type B donor into a type AB recipient Type O– donor into a type O+ recipient b.Explain how xenotransplantation might be successful in light of the immune system’s robust ability to recognize foreign antigen.

4.Summarize the role of the immune system in the development of type I diabetes. Propose a strategy that could be used to protect young children from developing an autoimmune reaction, and subsequently type I diabetes, after a viral infection.

5.A patient in your unit exhibits frequent bouts of microbial infections and is found to produce extremely low levels of IgG and IgM antibodies. Your colleague suggests that the patient receive numerous vaccinations against a broad spectrum of common pathogens; you disagree. Why? Explain another treatment that may be beneficial to this patient.

Chapter 17

1.Explain why specimens should be taken aseptically, even when nonsterile sites are being sampled and selective media are to be used, and explain why speed is important in the clinical testing process.

2.In the middle of an outbreak of measles (an infection that is highly communicable), a public health department is using immunologic testing to determine whether sick children have measles or not. If the children test positive, they are quarantined at home, and their contacts are counseled to update their MMR vaccine. In this situation, would you prefer to use a diagnostic test that is highly specific or one that is highly sensitive? Justify your answer.

3.Explain which type of ELISA can be used to determine an individual’s past exposure to a pathogen.

4.You are working at a health clinic, and a woman enters, suspecting that she was exposed to HIV two nights ago. a.Discuss whether or not she can be tested for HIV infection at this point. b.Summarize how you would respond to this patient, providing her with appropriate information regarding testing for HIV infection.

5.Compare and contrast the process of restriction analysis used in traditional DNA fingerprinting with the procedure used in pulse-field gel electrophoresis.

Chapter 18 

1.A young boy was at the playground when he felt a sharp pain on his leg. Upon inspection, his mother realized he had been stung by a bee. They went home and she carefully removed the stinger and washed the site well. Within a week, the site became swollen and painful; a red line appeared at the site, trailing up his leg.

a.Explain what condition the young boy appears to be suffering from and the most likely causative agent involved.

b.Discuss how the microbe may have gained access to the portal of entry.

2.A farmer working on a piece of machinery gets his shirtsleeve caught in a moving piece of the equipment. His shirt is sliced, and a sharp blade covered in mud slices through his upper arm. He attempts to control the bleeding and immediately seeks medical attention. After 3 days, he develops a fever and his arm becomes extremely swollen and painful. Pulling back the bandages, he finds that the wound has become blackened and is leaking a bloody fluid. Microscopic analysis of the fluid reveals the presence of gram-positive bacilli.

a.Discuss what condition the patient is suffering from and the likely causative agent of this infection.

b.Explain how the patient contracted this pathogenic microbe and what virulence factors contributed to the pathogenesis seen at the wound site.

c.In addition to antibiotics, the physician prescribes hyperbaric therapy. Describe what this treatment involves and how it could be therapeutic to this patient.

3.   a.Conduct additional research, and discuss whether “pox parties” represent a safe method of developing immunity to varicella zoster virus.

b.Provide evidence in support of or refuting the following statement: Shingles develops when you are reinfected with varicella zoster virus later on in life.

4.Smallpox has a rich history—from prompting the first vaccine to potential use as a bioterrorism agent. Given what you know about the etiology of the disease and the current state of the world’s immunity to smallpox, discuss how effective (or ineffective) a smallpox biological weapon could be against a human population.

5.Your coworker says that her spouse is in the hospital for elective surgery and his recovery is complicated by two infections: He has chicken pox all over the upper half of his body, and shingles on his legs. What questions will you ask for clarification?

Chapter 19

1.   a.Explain why the nervous system is described as “immunologically privileged,” and discuss whether this provides a beneficial or disadvantageous effect in this system.

b.Discuss the defenses a pathogen encounters as it attempts to gain entry into the nervous system.

2.Conduct research and summarize the causative agent and mode of transmission behind the multistate meningitis outbreak linked to steroid injections that occurred in 2012. How did improper physical and chemical control methods play a major role in this outbreak? Did portal of entry play any role?

3.Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting white-tailed deer and elk. In 2005, venison from a deer testing positive for CWD was served during an annual wild-game dinner in the town of Verona in upstate New York. Based upon your knowledge of vCJD and related spongiform encephalopathies and any additional research you conduct, discuss whether any of the attendees are at risk for developing disease in the future.

4.As you learned in section 8.3, many types of fruits and vegetables can be fermented into alcoholic beverages. Such was the case recently when prisoners in Utah attempted to make an illegal beverage called “pruno”; however, someone added a weeks-old baked potato to the mix, letting a microbe into the party who was clearly uninvited. Consumers of the pruno began to develop difficulty swallowing, vomiting, double vision, and muscle weakness; three required ventilation therapy. No deaths were attributed to the contaminated beverage.

a.What disease were the prisoners suffering from, and what was the causative agent involved?

b.Based upon your knowledge of this disease, what form of treatment was used to successfully avoid the worst outcomes of the disease in these patients?

5.In August 2011, a soldier from Fort Drum in Watertown, New York, tested positive for rabies; he died less than 3 weeks later. Further investigation revealed that he actually became infected when he was bitten by a dog in January of the same year while stationed in Afghanistan. Discuss any risks the soldier posed to his platoon, explaining whether or not this fatal outcome could have been avoided.

Chapter 20 

1.Explain why cases of dengue fever have been observed beyond endemic regions of the world today. Discuss whether or not completely eradicating mosquito (vector) populations from disease-ridden areas is advisable.

2.   a.Discuss whether or

not genetics plays a role in HIV infection, providing at least one example to illustrate your position.

b.Provide evidence in support of or refuting the following statement: An HIV-positive individual will always harbor the virus even if no viral load is detectable by PCR or other methods.

3.Explain why over the years the incidence of HIV infection has declined in the United States while the prevalence of AIDS has increased.

4.   a.Compare and contrast various characteristics of hemorrhagic and non hemorrhagic fever diseases.

b.Provide an explanation for the observed increase in incidence of these zoonotic infections around the world today.

5.Several pathogens in this chapter are listed as Category A bio weapons by the Centers for Disease Control and Prevention (CDC). What characteristics of the pathogens in this chapter make them suited for mass infection with high mortality?

 
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Homework

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Gender is determined by father, because he can give either the X or the Y chromosome.

It is estimated that from 10-20% of all human fertilized eggs contain chromosome abnormalities, and these are the most common cause of pregnancy failure.

These chromosome abnormalities:

● arise from errors in meiosis, usally meiosis I; ● occur more often (90%) during egg formation than during sperm formation; ● become more frequent as a woman ages. ● Aneuploidy – the gain or loss of whole chromosomes – is the most common chromosome

abnormality. ● Aneuploidy is caused by nondisjunction, the failure of chromosomes to separate correctly

o homologues during meiosis I or o sister chromatids during meiosis II

● Zygotes missing one chromosome (“monosomy”) cannot develop to birth (except for females with a single X chromosome).

● Three of the same chromosome (“trisomy”) is also lethal except for chromosomes 13, 18, and 21 (trisomy 21 is the cause of Down syndrome).

● Three or more X chromosomes are viable because all but one of them are inactivated.

X-Inactivation Human females inherit two copies of every gene on the X chromosome, whereas males inherit only one (with 18 exceptions: the 9 pseudoautosomal genes and the 9 “housekeeping” genes found on the Y). But for the hundreds of other genes on the X, are males at a disadvantage in the amount of gene product their cells produce? The answer is no, because females have only a single active X chromosome in each cell. During interphase, chromosomes are too tenuous to be stained and seen by light microscopy. However, a dense, stainable structure, called a Barr body (after its discoverer) is seen in the interphase nuclei of female mammals. The Barr body is one of the X chromosomes. Its compact appearance reflects its inactivity. So, the cells of females have only one functioning copy of each X-linked gene – the same as males. X-inactivation occurs early in embryonic development. In a given cell, which of a female’s X chromosomes becomes inactivated and converted into a Barr body is a matter of chance (except in marsupials like the kangaroo, where it is always the father’s X chromosome that is inactivated). After inactivation has occurred, all the descendants of that cell will have the same chromosome inactivated. Thus X-inactivation creates clones with differing effective

 

 

gene content. An organism whose cells vary in effective gene content and hence in the expression of a trait, is called a genetic mosaic.

X-Chromosome Abnormalities:

As we saw above, people are sometimes found with abnormal numbers of X chromosomes. Unlike most cases of aneuploidy, which are lethal, the phenotypic effects of aneuploidy of the X chromosome are usually not severe. Examples:

● Turner’s syndrome X0 (2n= 45): females with but a single X chromosome. The phenotypic effect is mild because their cells have a single functioning X chromosome like those of XX females. Number of Barr bodies = zero.

● XXX, XXXX, XXXXX karyotypes: all females with mild phenotypic effects because in each cell all the extra X chromosomes are inactivated. Number of Barr bodies = number of X chromosomes minus one.

● Klinefelter’s syndrome (2n= 47): people with XXY or XXXY karyotypes are males (because of their Y chromosome). But again, the phenotypic effects of the extra X chromosomes are mild because, just as in females, the extra Xs are inactivated and converted into Barr bodies.

Genetic Disorders – Diseases resulting from abnormalities in human genes

• Mutation in a single gene – absence or alteration of a protein. Ex. Hemophilia • Chromosomal disorder – Duplication, loss, or breakage. Ex. Down Syndrome

There are many genetic diseases and disorders (See Hand Out). Some are:

• Down Syndrome • Sickle cell anemia • Hemophilia • Fanconi’s anemia • Cystic fibrosis

Many Gross Chromosomal abnormalities don’t cause death and are sex chromosome related. Karyotypes are used to look at chromosome shape and to ensure there are no abnormalities with the fetus. This is done by looking at the embryo’s amniotic fluid (amniocentesis).

 

 
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Need Help With Biology Assignment

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Biodiversity Lab DOMAIN BACTERIA Bacteria are incredibly diverse, but they’re usually really tiny and hard to see, even under a standard microscope. On an agar plate, bacteria have the nutrients to divide quickly, eventually leading to clusters of rapidly dividing cells, or colonies, that are visible to the naked eye. Cyanobacteria, were the only lineage of organisms to evolve the complicated process of photosynthesis from scratch and, in doing so, oxygenated the Earth’s atmosphere paving the way for the evolution of Eukaryotes. Some Cyanobacteria, such as Nostoc and Anabaena, adhere to one another as they divide and form colonies that look like multicellular “algae” to the naked eye, thus leading to the common name “blue-green algae”. In low nitrogen environments, some of the cells in the colony will even change function to become anatomically different cells specialized for nitrogen fixation, which benefits the entire colony. Some other types of Cyanobacteria are

responsible for algal blooms that release toxins and gases that can be fatal to mammals such as dogs and humans. DOMAIN ARCHAEA Archaea are mostly tiny and hard to see, like bacteria. Most are also extraordinarily difficult to cultivate due to their extremophile lifestyles- thriving in extreme conditions that other organisms can’t tolerate. While we can’t replicate an anoxic or deep sea environment in the lab, we can replicate an extremely salty environment that halophilic Archaea such as Halobacterium prefer but which is toxic to nearly all other forms of life.

Many colors of life from left to right: 1. Anabaena, a photosynthetic blue-green alga (Domain Bacteria); 2. Halobacterium, a halophilic

Archaea; 3. Acrochaetium, a multicellular red alga (Archaeplastida); 4. Chlamydomonas, a single-celled, free swimming Chlorophyte

green alga (Archaeplastida); 5. Ectocarpus, a brown alga (Stramenopiles, S.A.R. clade)

 

 

 

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Eukaryotes EUKARYOTE SUPERGROUPS The best evidence from DNA sequences supports 4 major lineages within domain Eukarya; Excavata, S.A.R. Clade, Archaeplastida, and Unikonta. Excavata: -Euglena is a flagellated, photosynthetic Excavata that acquired its chloroplasts by endosymbiosis of a unicellular green alga (see Archaeplastida). They can move surprisingly fast, as you can see in this video: https://youtu.be/upPgx3GyBjQ Other lineages in Excavata cannot photosynthesize and must consume their food as existing organic matter. Some even use humans as food, such as the brain-eating amoeba Naegleria fowleri and the organisms that

cause the diseases African Sleeping Sickness and Chagas. S.A.R. Clade: Stramenopiles: – Diatoms produce cases made of silicon; they are photosynthetic and are important at the base of the food chain in both freshwater and saltwater aquatic environments. Brown algae are also in this group, ranging from single-celled to colonial to filamentous mulicellular organisms all the way to huge kelp almost 200 ft long.

Brown algae are large, multicellular Stramenopiles (S.A.R.)

Alveolates: -Paramecium is a heterotrophic (=must feed on organic matter) ciliate that lacks chloroplasts and uses small hair-like cilia to move around with amazing speed and agility for a single-celled organism as shown in this video: https://youtu.be/mFSIUuT0EgM -Dinoflagellates are photosynthetic flagellates that in high density cause toxic “red tides”. Some are also bioluminescent when agitated, as you can see in this video: https://youtu.be/5MiUxopM5VM

 

 

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Node #4, Stramenopiles+Alveolates, is often referred to as the group Chromalveolata, the ancestor of which likely picked up photosynthetic plastids by engulfing a unicellular Red Alga (see Archaeplastida). Rhizaria: -Foraminiferans most often make shells of Calcium Carbonate. Rhizaria extend long pseudopods out of these shells to gather food. One lineage of Rhizaria is photosynthetic by way of chloroplasts acquired through endosymbiosis of a unicellular green alga (Archaeplastida). Archaeplastida: Includes Red Algae, Green Algae, and plants; all red algae, green algae, and plants descended from a common unicellular ancestor at node 5 that engulfed a photosynthetic Cyanobacterium which became the earliest plastids in eukaryotes.

Embryophytes: (nonvascular) -Liverworts and Mosses spend the majority of their life cycle as haploid gametophyte plants that produce sperm and egg, with a short-lived diploid sporophyte life stage that produces and disperses spores

The diploid sporophytes of mosses (left) often look like upside-down golf clubs, but the main body

of the plant is haploid. In hemisphaeric liverwort (center), the diploid sporophyte

generation only exists as short-lived, round yellow globes that produce spores (right)

 

(vascular spore plants) -Lycophytes and Ferns still reproduce by spores like nonvascular plants and algae, but in vascular plants the diploid sporophyte life stage grows large and the haploid, gametophyte stage of the life cycle is usually small and short-lived

 

 

 

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Spikemosses (left) are diploid and produce spores. Ferns usually produce spores under their leaves (center). On the right, a dark green,

haploid fern gametophyte will soon be overgrown by the light green diploid sporophyte producing its first leaf. (seed plants- Gymnosperms) -Cycads are often called Sago Palms, although real palm trees are angiosperms that flower and fruit. -Ginkgo is represented by a single modern species; 270 million year-old fossils look identical (stasis). -Conifers are the largest group of living gymnosperms; most are needle-bearing evergreens. -Gnetophytes: Welwitschia mirabilis is a Namib Desert plant that only makes two continuously-growing leaves throughout its life

Representatives of the 4 extant Gymnosperm lineages (seed plants-Angiosperms) -Amborella trichopoda: All other 250,000+ species of flowering plant are more closely related to each other than they are to this woody shrub from the south pacific island of New Caledonia. -Monocots usually produce flower parts in 3’s or multiples thereof and parallel-veined leaves. Orchids are the largest family of monocots with over 25,000 species, and grasses are another huge family that provides most calories consumed by the human population (sugarcane, corn, wheat, oats, barley, rice, etc.) -Eudicots: Usually flower parts in 4s and 5s, net-veined leaves. The Sunflower family is the largest family of eudicots (and flowering plants overall) with more than 30,000 species. The “flowers” of members of the sunflower family are actually aggregations of up to hundreds of flowers.

 

 

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Amborella (left); representative eudicot and monocot flowers and fruits (right) Unikonta: The first major division in Unikonta (node 6) separates Amoebozoans from Opisthokonts. -Amoebozoans: Chaos carolinensis is a large amoeba that changes cell shape to extend pseudopods and engulf potential food particles for internal digestion as seen in this video: https://youtu.be/zgtWbJ2wSeg Fungi: Fungi range from unicellular (yeasts) to huge multicellular organisms, most of which grow as long, filamentous strands of cells known as hyphae. Masses of hyphae that are visible macroscopically are known as a mycelium. -Lichens: Lichens are actually a symbiotic relationship between two different supergroups: fungal hyphae (Unikonta) and a unicellular photosynthetic organism, usually a green alga (Archaeplastida). The hyphae farm the green alga as a carbon source while providing inorganic nutrients to the alga by slowly breaking down rock, bark, mineral soil, and other substrates.

(left) Lichens can be found growing on bark, rocks, or bare ground; even though they are given scientific names, they are really an

ecosystem of multiple organisms living together closely. (right) Giant puffball mushroom growing in lawn grass. -Mushrooms: Most mushrooms form from a dikaryotic mycelium; the hyphae forming the mycelium originate from fusion of hyphae from two haploid individuals. After these fuse, each cell of the dikaryotic mycelium contain two separate haploid nuclei and grow into a fruiting body. In surfaces that generate spores, individual

 

 

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cells will fuse the haploid nuclei into a zygote where recombination can occur. The zygote then undergoes meiosis to generate haploid spores that can disperse to grow haploid hyphae with new genetic combinations of both parents. -Molds are mycelia with filamentous hyphae that invade their substrate and secrete digestive enzymes to break down the substrate before absorbing small molecules. Animals: Animal phylogeny and diversity is mapped on its own tree. Keep in mind that the closest relative of animals in Unikonta are single-celled Choanoflagellates, and the closest relatives of fungi are single-celled Nucleariids. Thus, animals and fungi evolved multicellularity independently from one another. Animal lineages represented in the tree are listed below: Phylum Porifera: Sponges Phylum Cnidaria: Jellyfish, Hydra, Corals, etc. Deuterostomes: Phylum Hemichordata: Acorn Worms Phylum Echinodermata: Sea Stars, Sea Cucumbers, Sea Urchins Phylum Chordata: Cephalochordata: Lancelets/Amphioxus Tunicata: Tunicates, Sea Squirts Cyclostomes: Jawless Fish (Hagfish, Lamprey) Chondrichthyes: Cartillaginous Fish (Sharks, Rays) Actinopterygii: Ray-finned Fish, the most diverse lineage of vertebrates Dipnoi: Lungfish Amphibia: Caecilians, Salamanders, Frog & Toads Reptilia: Turtles, Lizards, Snakes, Crocodilians, Birds Mammalia: Mammals Lophotrochozoa: Phylum Platyhelminthes: Flatworms Phylum Mollusca: Clams, Oysters (bivalves), Snails, Slugs (gastropods), Octopus, Squid (Cephalopods) Phylum Annelida: Segmented Worms Ecdysozoa: Phylum Nematoda: Roundworms Phylum Arthropoda: Subphylum Chelicerata: Horseshoe Crabs, Ticks, Mites, Spiders, Scorpions Subphylum Myriapoda: Centipedes, Millipedes Subphylum Crustacea: Crabs, Shrimp, Pillbugs, Barnacles, etc. Subphylum Hexapoda, Class Insecta: Insects (well over half of all described animal species)

(left) Insects like this Pipevine Swallowtail make up more than half of all named animal species. Ray-finned fish, like the Etowah Darter (center) are the most diverse lineage of vertebrates. Birds, including Burrowing Owls (right), are the most diverse land vertebrate lineage.

 

 

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QUESTIONS Use the phylogenetic trees at the end of this pdf to answer the following questions. Clicking on the lineages on the phylogenetic trees will take you to the Wikipedia entry for that group. 1. Which node in the 3-domain supertree (the first tree) represents the common ancestor of eukaryotes and Archaea? Which node in the 3-domain tree represents the common ancestor of all Eukaryotes? What are some characteristics that would have been present in the common ancestor of all eukaryotes? Think about characteristics that are shared between your cells and the cells of all these other groups (2 pts).

2. List all of the acquisitions of photosynthetic found in eukaryotes below (give either the numbered node where it evolved or the name of the lineage in which it occurred) (2 pts). 3. Unikonta don’t have any true chloroplasts or photosynthetic lineages, but describe the similarities and differences between Lichens and chloroplast-containing eukaryote lineages. (1 pt) 4. Identify the node in the Archaeplastida phylogeny where the diploid sporophyte generation became the dominant stage in the life cycle (1 pt). 5. Identify the node in the Archaeplastida phylogeny where land plants evolved. (1 pt) 6. Which node represents the most recent common ancestor of Seed Plants? (1 pt)

 

 

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7. Which node represents the most recent common ancestor of Gymnosperms. Conifers are, by far, the most species-rich lineage of modern Gymnosperms; do you think the most recent common ancestor of seed plants would have had needles like a pine tree or broad leaves more like most angiosperms? (2 pts) 8. Which node is the most recent common ancestor of Angiosperms (flowering plants)? These are now the most species-rich lineage of embryophytes by far with approximately 350,000 species. Most of these species (including all monocots) are herbaceous, meaning they don’t form a woody trunk with internal vascular rings or bark Amborella trichopoda is a shrub from New Caledonia that represents the basal branch of Angiosperms (i.e. all other flowering plants are more closely related to each other than they are to Amborella). Do you think the ancestor of angiosperms was woody or herbaceous? What about the ancestor

of all seed plants? (hint: Amborella, Ginkgo, all conifers, Gnetophytes, and Cycads have woody “trunks”)? (2 pts) 9. Sponges have specialized individual cells but lack true tissue (masses of coordinated cells, like muscle, nerve, etc.). At what node in the animal phylogeny did true tissues evolve? (1 pt) 10. At what node in the animal phylogeny did bilateral symmetry evolve (hint: sponges and cnidarians aren’t bilaterally symmetric, but every other organism on the animal tree technically is)? Bilaterally symmetric animals have a left and right side, as well as a dorsal and ventral side. Based on the organisms on this tree, what do you think this bilateral common ancestor may have looked like? (2 pts) 11. You have two forelimbs (arms) and two hindlimbs (legs). At which node in the phylogeny did these paired appendages evolve? Are there any instances of convergent evolution of paired appendages? Are there any instances of losses of paired appendages? Give the examples, if they exist (2 pts).

 

 

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12. Identify the node in the phylogeny where your ancestor first colonized land (hint: this is also the common ancestor of organisms with fingers and toes). Give an example of a descendant from that ancestor that has gone back to living a fully aquatic lifestyle. List any other examples of animal lineages that appear to have colonized land independently of your ancestor (2 pts). 13. Are fish (i.e. jawless fish, cartilaginous fish, ray-finned fish, and lungfish) monophyletic? i.e. Do they trace

back to a single common ancestor, and are all descendants of that most recent ancestor considered fish? (1 pt). 14. Chambered Nautilus is the first-branching lineage of Cephalopods. Do you think Octopuses/Octopi evolved from a shelled ancestor? Explain why or why not (1 pt). 15. List all of your ancestors (list of node numbers) from both the animal tree and the 3-domain tree. (2 pts). 16. Go outside and take photographs of 4 different organisms, each representing a different terminal group on the tree. Identify where they belong on the tree and submit photographs. A maximum of 2 animals or 2 plants are allowed, and at least one of your selections must be something other than an animal or plant. (2 pts)

 
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