Assignment: Biology for a Changing World Chapter 12 & 17 Summary

Assignment: Biology for a Changing World Chapter 12 & 17 Summary

Michèle Shuster • Janet Vigna • Matthew Tontonoz Biology for a Changing World Fourth Edition Lecture Slides CHAPTER 17 Prokaryotic Diversity Macmillan Learning © 2021 Chapter 17 Prokaryotic Diversity Driving Questions 1. What is the human microbiome, and what is its role in health, disease, and forensics? 2. What are prokaryotes, and why are they classified into two distinct domains of life? 3. What are features of bacteria and archaea? The Human Microbiome (1 of 2) Microbiome: the diversity of microbes living in and on us • Microbial diversity varies by the part of the body where they occur. • Microbes contribute to the immune system and are part of normal physiology. The Human Microbiome (2 of 2) • Each person has a unique combination of microbe species. • Microbes vary from one portion of the body to another. • They even vary from one hand to another. Prokaryotic Cells (1 of 3) Prokaryotes • Unicellular • Lack internal membranebound organelles • DNA is not contained within a nucleus. • Most of the microbes in our microbiome are prokaryotes. Prokaryotic Cells (2 of 3) Size • Approximately 1/100th the size of a eukaryotic cell • Similar to the size of a eukaryotic mitochondrion • 1–10 microns Prokaryotic Cells (3 of 3) • Reproduce quickly • Found in the trillions on humans • Able to share DNA with each other • Sharing DNA helps them to adapt to diverse environments. Microbial Forensics (1 of 3) • We leave traces of microbial diversity on things we touch.

• The microbes we leave can be detectable for up to two weeks. • Investigators can identify suspects and victims of crimes using microbes they find on surfaces. Microbial Forensics (2 of 3) • It is possible to estimate both who touched a surface (like fingerprints) and when they touched it. • When we touch surfaces, we deposit millions of microbes. • Over time, the microbes we leave behind become less common. Microbial Forensics (3 of 3) • To solve crimes, we sometimes need to know the age of a corpse. • After death, bacteria from the environment cause decay. • It is possible to identify when a person died by examining which microbes are present. Prokaryotic Domains •Prokaryotes come from two domains of life. •Bacteria •Archaea •Both are part of the human microbiome. Bacteria (1 of 2) • Most possess a cell wall. • Tremendous genetic diversity • Differences in nutrition, metabolism, structure, and lifestyle Bacteria (2 of 2) • Autotrophs: make their own food from material in nonliving environment • Heterotrophs: rely on other organisms as a food source Bacteria: Autotrophs (1 of 2) Cyanobacteria • largest group • in oceans, freshwater, exposed rocks, and soil • photosynthesize • oldest photosynthetic organisms • Some perform nitrogen fixation. – conversion of atmospheric nitrogen into a form that plants can use for growth Bacteria: Autotrophs (2 of 2) • Some species obtain energy from geological sources. – inorganic gases of hydrothermal vents • These species do not rely on sunlight at all. Bacteria: Heterotrophs • Decomposers (recyclers) – recycle trapped carbon and other elements • Bioremediation – oil spills • Fermenters – Lactobacillus bulgaricus in yogurt Bacteria: Structure (1 of 2) • Spherical (cocci) • Rod-shaped (bacilli) • Spiral (spirochetes) • Flagella: tiny, whiplike structures that project from the cell and help it move Bacteria: Structure (2 of 2) • Pili: shorter, hairlike appendages that enable bacteria to adhere to a surface • Capsule: a sticky outer layer that helps the cell adhere to surfaces to avoid the defenses of the host Bacteria: Symbiosis • Many live in close association, or symbiosis, with other organisms.

• Can be beneficial – such as Vibrio fischeri, bioluminescent, lives and feeds inside the light organs of certain species of squid Bacteria: Pathogens Pathogens • Disease-causing agents • Cause disease by producing toxins that harm their hosts – strains of Escherichia coli secrete a toxin that causes bloody diarrhea, kidney failure, and sometimes death in its host Archaea (1 of 2) • Lack a nucleus like bacteria • As different from bacteria as they are to us • Originally thought to be more ancient than bacteria Archaea (2 of 2) • Genetically distinct from bacteria • Some archaea are “Extremophiles” – hyperthermophiles – methanogens – halophiles • Some archaea are part of the human microbiome. Microbiome Sources • We gain our unique microbiome during the first 1–2 years of life from various sources: • birth • breastfeeding • diet • other environmental sources Microbiomes and Disease (1 of 2) • Microbiomes in primitive societies have more of some disease-causing bacteria. • People in industrialized societies have more heart disease, autoimmune disease, and autism. • These may be associated with the microbiome. Microbiomes and Disease (2 of 2) • Microbiomes in primitive societies have more of some disease-causing bacteria. • People in industrialized societies have more heart disease, autoimmune disease, and autism. • These may be associated with the microbiome. Microbiome Hope • If having the wrong microbiome causes disease, then can changing our microbiome cure disease? • Highly effective treatment for Clostridium difficile infection: • Fecal transplant from the gut of a healthy person to the gut of a sick person Microbiome Hype • Differences in microbiome can be associated with disease. • However, correlation does not mean causation. • For example: • Autistic people have different microbiomes, but they also tend to be picky eaters.

• Does the microbiome cause autism, or are both caused by other factors? Diet and the Microbiome • Diet: major driver of microbiome compositions • Fiber-rich diet: • promotes healthy microbial diversity • leads to healthy regulation of body systems • Fiber-poor diet: • promotes low microbial diversity • leads to inflammation and disease Summary (1 of 3) What is the human microbiome, and what is its role in health, disease, and forensics? • The human microbiome consists of the microorganisms—bacteria, archaea, protists, and fungi—living on and in us. • Our microbiome begins to be acquired at birth. • Our individual microbiome can be used to identify objects that we have touched, based on the microbial fingerprints that we leave. • Disruptions to our microbiome can lead to disease. • Restoration of our microbiome (e.g., through fecal transplant) can restore a state of health. Summary (2 of 3) What are prokaryotes, and why are they classified into two distinct domains of life? • Prokaryotes are unicellular organisms that lack organelles, have no nucleus, and are found in virtually every environment on Earth. • Genetic analysis has led to the categorization of life prokaryotes into two domains: Bacteria and Archaea. • Both bacteria and archaea have prokaryotic cells, but they otherwise differ in their genetics, biochemistry, and lifestyles. Summary (3 of 3) What are features of bacteria and archaea? • Bacteria are diverse and have many unique adaptations that allow them to live and thrive in many environments. • Some bacteria cause disease, but most are harmless, and many are beneficial. • Some archaea live in some of the most extreme environmental conditions on Earth, whereas others live in more mild conditions. Interpreting Data (1 of 2) It has been suggested that increasing rates of immune disorders, such as asthma and some food allergies, are the result of a reduced exposure to a diversity of “friendly” bacteria in the human microbiome. a. Based on the data shown in the bar chart, which population would you predict to have the lowest rates of asthma and allergies? Note that the Amerindians are from rural communities in Venezuela.

Interpreting Data (2 of 2) b. If your prediction is correct, is that evidence of correlation or causation? c. Design an epidemiological study to test the hypothesis that reduced diversity of the human microbiome is responsible for increasing rates of immune disorders. (Hint: Refer back to Chapter 1 for observational and epidemiological studies). Mini Case (1 of 5) Your friend’s mother has been hospitalized and has developed a Clostridium difficile (C. diff) infection of the colon. This is a common hospital-associated infection, in which the use of antibiotics to treat another infection reduces the normal microbiome of the colon, allowing C. diff to establish itself. Mini Case (2 of 5) Her doctor is recommending a fecal microbial transplant (FMT), in which feces from a healthy donor are transferred into the intestinal tract of a person with C. diff (either by enema or by a tube extending from the nose to the small intestine). Your friend and her mother find this idea to be disgusting, particularly when they realize that the donor fecal material is not sterilized before the transplant. Mini Case (3 of 5) Data from a clinical trial comparing FMT to standard antibiotic therapy with vancomycin are shown in this bar chart. What can you infer about the effectiveness of FMT compared to vancomycin treatment? Mini Case (4 of 5) More results from the clinical trial on FMT is shown in this bar chart. a. What do you observe about the microbial diversity in patients versus donors? b. What do you observe about the microbial diversity in patients before and after treatment? Mini Case (5 of 5) c. What can you infer about how the FMT works? d. Based on your answer to part c, why can’t the donor fecal material be sterilized? e. Based on the data presented, what treatment do you encourage your friend’s mother to choose? Explain your answer. Michèle Shuster • Janet Vigna • Matthew Tontonoz Biology for a Changing World FOURTH EDITION Lecture Slides Chapter 12 Complex Inheritance Macmillan Learning © 2021 Chapter 12 Complex Inheritance Driving Questions 1. How do chromosomes determine sex, and how does sex influence the inheritance of certain traits? 2. What inheritance patterns are observed when alleles are not simply dominant or recessive?

Important information for writing discussion questions and participation

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Hello class and welcome to the class and I will be your instructor for this course. This is a -week course and requires a lot of time commitment, organization, and a high level of dedication. Please use the class syllabus to guide you through all the assignments required for the course. I have also attached the classroom policies to this announcement to know your expectations for this course. Please review this document carefully and ask me any questions if you do. You could email me at any time or send me a message via the “message” icon in halo if you need to contact me. I check my email regularly, so you should get a response within 24 hours. If you have not heard from me within 24 hours and need to contact me urgently, please send a follow up text to

I strongly encourage that you do not wait until the very last minute to complete your assignments. Your assignments in weeks 4 and 5 require early planning as you would need to present a teaching plan and interview a community health provider. I advise you look at the requirements for these assignments at the beginning of the course and plan accordingly. I have posted the YouTube link that explains all the class assignments in detail. It is required that you watch this 32-minute video as the assignments from week 3 through 5 require that you follow the instructions to the letter to succeed. Failure to complete these assignments according to instructions might lead to a zero. After watching the video, please schedule a one-on-one with me to discuss your topic for your project by the second week of class. Use this link to schedule a 15-minute session. Please, call me at the time of your appointment on my number. Please note that I will NOT call you.

Please, be advised I do NOT accept any assignments by email. If you are having technical issues with uploading an assignment, contact the technical department and inform me of the issue. If you have any issues that would prevent you from getting your assignments to me by the deadline, please inform me to request a possible extension. Note that working fulltime or overtime is no excuse for late assignments. There is a 5%-point deduction for every day your assignment is late. This only applies to approved extensions. Late assignments will not be accepted.

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Plagiarism is highly prohibited. Please ensure you are citing your sources correctly using APA 7th edition. All assignments including discussion posts should be formatted in APA with the appropriate spacing, font, margin, and indents. Any papers not well formatted would be returned back to you, hence, I advise you review APA formatting style. I have attached a sample paper in APA format and will also post sample discussion responses in subsequent announcements.

Your initial discussion post should be a minimum of 200 words and response posts should be a minimum of 150 words. Be advised that I grade based on quality and not necessarily the number of words you post. A minimum of TWO references should be used for your initial post. For your response post, you do not need references as personal experiences would count as response posts. If you however cite anything from the literature for your response post, it is required that you cite your reference. You should include a minimum of THREE references for papers in this course. Please note that references should be no more than 5 years old except recommended as a resource for the class. Furthermore, for each discussion board question, you need ONE initial substantive response and TWO substantive responses to either your classmates or your instructor for a total of THREE responses. There are TWO discussion questions each week, hence, you need a total minimum of SIX discussion posts for each week. I usually post a discussion question each week. You could also respond to these as it would count towards your required SIX discussion posts for the week.

I understand this is a lot of information to cover in 5 weeks, however, the Bible says in Philippians 4:13 that we can do all things through Christ that strengthens us. Even in times like this, we are encouraged by God’s word that we have that ability in us to succeed with His strength. I pray that each and every one of you receives strength for this course and life generally as we navigate through this pandemic that is shaking our world today. Relax and enjoy the course!

Hi Class,

Please read through the following information on writing a Discussion question response and participation posts.

Contact me if you have any questions.

Important information on Writing a Discussion Question

• Your response needs to be a minimum of 150 words (not including your list of references)
• There needs to be at least TWO references with ONE being a peer reviewed professional journal article.
• Include in-text citations in your response
• Do not include quotes—instead summarize and paraphrase the information
• Follow APA-7th edition
• Points will be deducted if the above is not followed

Participation –replies to your classmates or instructor

• A minimum of 6 responses per week, on at least 3 days of the week.
• Each response needs at least ONE reference with citations—best if it is a peer reviewed journal article
• Each response needs to be at least 75 words in length (does not include your list of references)
• Responses need to be substantive by bringing information to the discussion or further enhance the discussion. Responses of “I agree” or “great post” does not count for the word count.
• Follow APA 7th edition
• Points will be deducted if the above is not followed

• Remember to use and follow APA-7th edition for all weekly assignments, discussion questions, and participation points.
• Here are some helpful links
• The is a great resource