Final-Exam-2016 Answer Key

docx

School

Cornell University *

*We aren’t endorsed by this school

Course

2750

Subject

Anthropology

Date

Dec 6, 2023

Type

docx

Pages

Uploaded by StudentCU

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ Section #1 (30 points) _______________ Section #2 (22 points) _______________ Section #3 (48 points) _______________ Total (Max = 100) _______________  Print your name in LARGE letters on the BACK OF THE LAST PAGE of the exam.  Your TA (please circle one) Yiping Yiqin Megan Jem Nicole Shuo Deborah  There are three sections to this exam:  Section 1: Multiple Choice questions. You should answer 10 of the 12 questions. Each question is worth 3 points, for a maximum total of 30 points. If you answer a question but then decide you don't want it graded, put an X through your answer. The same for the other sections.  Section 2: True/False questions . You should answer 11 of the 13 questions. Each question is worth 2 points, for a maximum total of 22 points.  Section 3: Short Answer Questions . You should answer 8 of the 9 questions. Each question is worth 6 points, for a total maximum of 48 points.  Each student in this course is expected to abide by the Cornell University Code of Academic Integrity. Any work submitted by a student in this course for academic credit will be the student's own work. ( Educational Policy Committee , 3/5/02) 1

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ SECTION 1: MULTIPLE CHOICE QUESTIONS (30 points)  Answer any 10 of the following 12 multiple choice questions. If you answer more, only the first 10 will be graded. (3 points each for 30 points)  Write the answer before the question number. There is only one correct answer for each question. 1. What is Dr. Gu’s favorite cellular organelle in his research? (This question is designed to check your attendance) A. Ribosome B. Mitochondrion (Correct) C. Nucleus D. Endoplasmic reticulum 2. Which of the following hypotheses states that reduced fetal growth is strongly associated with a number of chronic conditions later in life? A. Thrifty genotype hypothesis B. Thrifty phenotype hypothesis (Correct) C. Drifty gene hypothesis D. Hygiene hypothesis 3. Which combination of bacterial types is most common in the human body? A. Firmicutes and Actinobacteria B. Firmicutes and Bacteriodetes (Correct) C. Bacteriodetes and Proteobacteria D. Actinobacteria and Proteobacteria 4. Which of the following is one of the benefits of the normal gut microbiota presented in class? A. Synthesize and excrete vitamins B. Prevent colonization by pathogens C. Help maintain a normal body temperature D. A and B (Correct) E. All of the above 5. Which of the following is not a type of genetic change which typically results in mitochondrial diseases? A. Mutations B. Deletions C. Transposable elements (Correct) D. Insertions 2

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ 6. Which of the following is a possible EVOLUTIONARY cause of aging? A. Telomere shortening B. Antagonistic pleiotropy (Correct) C. Mitochondrial heteroplasmy D. High estrogen levels 7. Which of the following could influence human gut microbiota composition? A. Diet B. Prebiotics and probiotics C. Host genotypes D. All of the above (Correct) 8. Which gene do people usually use for gut microbiota research? A. 23S rRNA B. 16S rRNA (Correct) C. 18S rRNA D. 5S rRNA 9. Which of the following provides evidence to support the hygiene hypothesis? A. Novel environments bring new health threats. B. The negative spatial correlation of pathogens and Type 1 diabetes. (Correct) C. The mutation Delta32 is found in higher frequencies in populations where the Black Death hit hardest. D. The “backward” arrangement of the human retina. 11. The smoke detector principle is NOT characterized by: A. Many false alarms B. High probability of death if there is a response with no real threat (Correct) C. A low cost of a minor inconvenience D. A high cost of death 12. Which infectious disease was the first emerging infectious disease of the 21st century as we discussed in class? A. Polio B. H1N1 influenza C. SARS (Correct) D. Tuberculosis 13. What selective pressure was removed according to the drifty gene hypothesis, leading to 3

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ increased rates of obesity? A. Metabolic diseases B. Predation (Correct) C. Infectious diseases D. Feast and famine cycles SECTION 2: TRUE/FALSE QUESTIONS (2 points each for 22 points) Answer any 11 of the following 13 TRUE/FALSE questions. If you answer more, only the first 11 will be graded. 1. __F__ Type 2 diabetes is an autoimmune disease resting from insulin resistance 2. __T__ The frequency of mitochondrial diseases is estimated to be roughly 1 in every 4,300 people 3. __F__ The Delta32 allele is an adaptation whose evolution was due to the spread of HIV, and which gives increased resistance to HIV infection. 4. __F__ The ratio of bacterial genes to human genes in our bodies is about 1:1 5. __F__ If 1/N of a virus population is resistant to drug A, and 1/M is resistant to drug B, the chance that a virus is resistant to both A and B is 1/N + 1/M. 6. __T__Research shows that mice raised in a germ-free environment display underdeveloped immune systems. 7. __F__ Longer lifespan for an organism always correlates with leaving behind more offspring. 8. __T__ mtDNA has a much higher density of protein-coding genes than nuclear DNA. 9. __F__ Natural selection always favors high virulence of a pathogen within its host. 10. __T__ Brown adipose tissue uses mitochondrial metabolism to generate heat in response to cold. 11. __T__ The Hygiene Hypothesis explains why rates of autoimmune diseases in the developed world are rising. 12. __T__ Farm children are less likely to have allergies than children from cities. 13. __T__Gut microbiota changed dramatically from first (T1) to third (T3) trimesters during pregnancy. T3 stool showed strongest signs of inflammation and energy loss. When transferred to germ-free mice, T3 microbiota induced greater adiposity and insulin insensitivity compared to T1. 4

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ SECTION 3: SHORT ANSWER QUESTIONS: (6 points each for 48 points)  Answer 8 of the following 9 questions. If you answer more, only the first 8 will be graded. Limit your answers to the space provided below the question. 1. List three evolutionary mechanisms of aging and explain each one of them. Antagonistic pleiotropy is the theory that some adaptations that increase fertility also cause decreased lifespan (2 points). Disposable soma is the theory that organisms put only the minimum amount of energy necessary into maintaining their bodies, with the remainder used for reproduction (2 points). Mutational accumulation is the theory that natural selection is less effective at removing somatic mutations later in life, due to increased extrinsic mortality by then (2 points). 2. Describe what is observed when germ-free mice have the gut bacteria of ob/ob mice transplanted in them. In comparison, what is observed when they have the gut bacteria of wild mice in them? What conclusion could you draw from this experiment? Germ-free mice with microbiota transplanted from ob/ob mice display increased weight gain, whereas mice with wild-type transplanted microbiota display normal weight (4 points). You can conclude from this that the microbiota play a role in regulating the host's weight (2 points). 5

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ 3. Define what extrinsic mortality is, especially its effect on natural selection. How does extrinsic mortality help explain the continued incidence of Huntington's disease (Hint: the average age of incidence of Huntington's is 35.5 years). Extrinsic mortality is deaths in a population from random factors, such as accidents and non-age- specific diseases (2 points). This causes natural selection to become weaker later in life, as fewer organisms are likely to be alive and reproduce by then (2 points). This allows the mutation causing Huntington's disease to continue, since the disease only becomes apparent after most human reproduction occurs (2 points). 4. Define what evolutionary medicine is, and give five categories of evolutionary reasons for why imperfections in the body exist. Evolutionary medicine is the application of evolutionary theory to understanding why human disease occurs (1 points). Five categories we went over in class are defense, trade-offs, constraints, new environment, and conflict (5 points). 6

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ 5. Describe the trade-off hypothesis with respect to the evolution of virulence. What benefits and drawbacks are associated with high virulence for a pathogen? Give an example of a pathogen with high virulence. High virulence allows a pathogen to grow quickly and spread to new hosts, but may kill an old host quickly before it can infect new hosts. (2 points) Low virulence allows hosts to survive longer for more infection, but the chance of infection with each individual new host goes down. (2 points) An example of high-virulence diseases are water and insect-borne ones like cholera and malaria. (2 points) 6. Please list and briefly explain three evolutionary hypotheses we discussed in class/discussion sections that are related with obesity. If people found a strong negative correlation between obesity risk allele frequencies and distance from the equator among different human populations, what hypothesis can help you explain this observation? Why? Three hypotheses are thrifty genotype, which states that people are genetically adapted to eat a lot and store fat during times of feast to prepare for famine, drifty genotype, which states that obesity is the result of neutral drift due to lack of pressure from predation, and adaptation to cold environments, which favor higher resting metabolic rates to generate heat (4 points). Correlation of obesity alleles with distance from the equator favors the third hypothesis (2 points). 7

NS/ANTH 2750: Human Biology & Evolution Final Exam, 12/12/2016 9:00 – 11:30 am Name:________________________ 7. What is heteroplasmy? How can heteroplasmy possibly contribute to aging? Heteroplasmy is the condition of multiple alleles of a mitochondrial gene existing together in the same cell (2 points). It may contribute to aging since with more cell divisions, mitochondrial mutations in some cells may drift to high heteroplasmic frequency, causing decreased cellular function and tissue degeneration (4 points). 8. Please explain somatic evolution of cancer based on four requirements for natural selection Somatic evolution satisfies the four requirements of natural selection due to cell division, which allows for reproduction of cells, cellular heterogeneity which creates phenotypic variation, heredity, since genetic and epigenetic mutations are passed on through cells, and predation from immune cells and competition for nutrients and space, which creates selection pressure. (1.5 points each) 9. Please explain the following statement “ each catastrophic epidemic event in human history (was) the ironic result of humanity’s steps forward ” New diseases have continuously arisen throughout human history, as changes in society and lifestyle make life better in general, but also give new conditions and environments for pathogens to arise (6 points). 8

Final-Exam-2016 Answer Key

Related Documents