short answer questionstanford university：簡(jiǎn)短回答問(wèn)題斯坦福大學(xué)

1、Human Biology 3AWinter Quarter 2001-2002March 21, 2002HUMAN BIOLOGY 3A FINALHONOR CODE: In recognition and in spirit of the Honor Code, I certify that I will neither receive nor give unpermitted aid on this examination, and I have neither given nor received unpermitted aid in preparing for this exam

2、ination. I will report to the best of my ability all Honor Code violations I observe.Name: (please print) _Signature: _SUID: _PLEASE READ ALL OF THIS BEFORE YOU START:1. FIRST, immediately write your Code number on one side of EVERY PAGE of this exam AND on the scantron sheet. 2. You should have the

3、 following exam pages: page 1 is the cover sheet, pages 2-21 contain exam material, and page 22 is the score sheet.3. Look through the exam before answering any questions. Note the point value of each question and allot your time accordingly. Be sure to allow enough time to complete the short answer

4、 questions.4. Put your NAME, SUID#, and CODE on your scantron sheets on both sides. Use the SCANTRON sheet to answer all TRUE/FALSE and MULTIPLE CHOICE questions. Use a No. 2 pencil only for your answers. There is only one correct answer per question. Be sure to fill in the bubbles carefully and rem

5、ove all stray marks from your scantron sheet. 5. Answer the questions on pages 10-21 on your test copy. Use a non-erasable blue or black PEN only for the short answer questions. We will not accept regrades if the original exam was written in pencil or red ink.6. DO NOT EXCEED THE ALLOTTED LINE LIMIT

6、 FOR EACH QUESTION! The limits are intended to indicate how general or specific the answer should be. Only the material within the alloted space will be graded. You have 3 HOURS to complete the exam. GOOD LUCK! PART 1: MULTIPLE CHOICE (2 points each)Pick up your number 2 pencil and your scantron she

7、et and get rolling! Put your NAME, SUID#, and CODE NUMBER on the scantron immediately. Answer the following multiple choice questions on your scantron. Remember to choose the BEST answer, and be careful when you bubble in your answer. 1. The free energy for the hydrolysis of ATP to ADP is given by:G

8、 = G + 1.4 kcal/mollog10ADPATPAssume that the standard free energy (G) for this reaction is -7 kcal/mol. At equilibrium, what is the ratio of ADP to ATP?a. 10-5b. 10-3c. 1d. 103e. 1052. Although most proteins adopt a well-defined folded structure in solution (and in cells), some proteins are unstruc

9、tured and unfolded. An example of such a protein is Sic1, a cytosolic protein that plays an important role in cell cycle regulation in budding yeast. A variety of structural methods have unequivocally established that Sic1 is floppy and unfolded, not structured and folded.On the basis of this inform

10、ation, which of the following hypotheses seems most likely to be true?a. Sic1 contains an unusually high proportion of cysteine residuesb. Sic1 contains an unusually low number of phosphorylation sitesc. Sic1 contains an unusually low proportion of hydrophobic residuesd. Sic1 is an unusually large p

11、roteine. Sic1 forms a beta barrel3. Which of the following statements about components of the cell membrane is FALSE?a. Membrane lipid molecules have both hydrophilic and hydrophobic regions.b. In cells, the two layers of a lipid bilayer have different lipid compositions.c. Channel proteins pump ion

12、s up their concentration gradients. d. The lipid bilayer is essentially impermeable to ions and large polar molecules, but is permeable to small nonpolar molecules such as carbon dioxide and steroid hormones.e. Transmembrane proteins usually span the lipid bilayer as one or more alpha helices.4. The

13、 transport of protons between the intermembane space and the mitochondrial matrix is critical for ATP synthesis. Which of the following statements is TRUE?a. Components of the electron transport chain pump protons from the intermembane space into the matrix.b. ATP synthase can pump protons into the

14、intermembrane space.c. The movement of protons into the intermembrane space makes the pH of the intermembrane space increase.d. The movement of protons into the intermembrane space makes the electrical potential of the intermembrane space become more negative.e. Plants have chloroplasts and can ther

15、efore live without mitochondria.5. Which of the following statements about proteins is FALSE?a. Signal sequences direct proteins to the correct cellular compartment.b. Proteins enter the nucleus through nuclear pores.c. Proteins unfold to enter the mitochondrion.d. When secretory vesicles fuse with

16、the plasma membrane, their protein contents are deposited in the cytoplasm.e. A single protein molecule may contain multiple start transfer and stop transfer sequences.6. Which of the following statements is TRUE?a. Protein kinases transfer phosphate from ATP to serine, threonine, and tyrosine resid

17、ues on substrate proteins.b. Trimeric G-proteins transfer phosphate from GTP to serine, threonine, and tyrosine residues on substrate proteins.c. Cyclic AMP is the regulatory subunit of cyclin-dependent kinasesd. Seven-pass transmembrane receptors transfer phosphate from ATP to serine, threonine, an

18、d tyrosine residues on substrate proteins.e. Seven-pass transmembrane receptors transfer phosphate from GTP to serine, threonine, and tyrosine residues on substrate proteins.7. During mitosis, the mitotic cyclins abruptly decrease in concentration as cells move from metaphase to anaphase. What best

19、explains this decrease?a. A decrease in the rate of cyclin transcriptionb. A decrease in the rate of cyclin translationc. An increase in the rate of cyclin proteolysisd. Export of cyclin from the nucleuse. An increase in the synthesis of S-phase cyclins8. An IgG molecule is composed of:a. One heavy

20、chain and two light chainsb. Four peptide chains held together by disulfide bondsc. A pentameric array of heavy chains and light chainsd. Two Class I MHC proteins and two Class II MHC proteinse. Chicken wire, donut juice, and oregano9. Which of the following statements is true of BOTH spermatogenesi

21、s and oogenesis?a. There is continuous proliferation of the gametes after puberty.b. Cytoplasmic bridges connect the gametes in development.c. There is unequal distribution of the cytoplasm between daughter cells.d. Support cells actively contribute to the development of the gamete. e. A small minor

22、ity of gametes complete meiosis.10. Calcium is directly involved in all of the following aspects of fertilization EXCEPT:a. corticle granule releaseb. acrosomal reactionc. sperm motilityd. sperm binding to ZP3 glycoproteine. all of the above aspects of fertilization involve calcium11. Please choose

23、the phrase that completes this sentence and makes it a TRUE statement: Mammalian cleavage: _a. is synchronous.b. begins before the egg has completed meiosis.c. results in the determination of the zygote into three major cell types.d. is characterized by compaction of cells.e. uses maternal mRNA afte

24、r the 8-cell stage.12. The epiblast contains all of the cells that will generate the embryo. However, not all the cells in the epiblast differentiate into embryonic structures. Which of the following extraembryonic tissues are derived from the epiblast?a. the lining of the yolk sacb. the lining of t

25、he amnionc. the cytotrophoblast of the choriond. the synctiotrophoplast of the chorione. the uterine endometrium of the decidua13. The first cells to migrate through the node in mammalian gastrulation will most likely form:a. anterior ectodermb. anterior endodermc. posterior ectodermd. posterior mes

26、oderme. posterior endoderm14. Ectoderm: skin :a. endoderm : rib cartilageb. endoderm : lungsc. endoderm : gonadsd. mesoderm : lining of the gutc. mesoderm : peripheral neurons15. As an induction experiment, you remove the notochord from a developing chick before the onset of neural tube differentiat

27、ion. You then implant various substances in place of the notochord. Which of the following implants would NOT induce normal pattern formation in the neural tube?a. Cells taken from a notochord at 8 weeks gestation.b. Cells taken from an active neural floor plate.c. Cells taken from an active ZPA.d.

28、A bead soaked in Shh.e. All of these implants would induce normal patterning of the neural tube.16. You have in your possession two chimeric mice that were made using transgenic laboratory techniques. Both mice have patches of black fur and patches of white fur. Assume that the gene for fur color is

29、 on an autosomal chromosome, black fur color is a completely dominant allele, and white fur is recessive. One mouse is male, one is female, and both have functional reproductive systems with chimeric germ cells. You allow them to mate. All of the following progeny could be produced from this mating

30、EXCEPT:a. A female mouse with all white furb. A male mouse with all white furc. A male mouse with all black furd. A female mouse with black and white fure. Two female mice with white fur who are conjoined twins17. Please choose the phrase that completes this sentence and makes it a true statement. E

31、mbryonic stem cells: _. a. can differentiate into only one cell type.b. are derived from the trophoblast.c. can be extracted from cloned embryos.d. can be derived from the bone marrow.e. are often used to make cloned embryos. 18. Hox genes are involved in patterning the anterior-posterior axis of th

32、e body. Which of the following statements about Hox genes is FALSE?a. There is significant expression of all Hox genes in the anterior region of the body.b. Knocking out particular Hox genes causes segment-specific malformations.c. Each segment of the body is associated with a unique combination of

33、Hox gene expression.d. The similarity of Hox expression patterns between Drosophila and mammals suggests that this patterning mechanism is ancient.e. Exogenous retinoic acid exposure can dramatically alter Hox gene expression.19. You have a culture of mouse limb bud cells that transcribe a gene, A,

34、in response to Shh. Which of the following changes in these cells would INCREASE transcription of A?a. Their Patched proteins cannot bind to Shh.b. Their Smoothened proteins cannot bind Ptch.c. Their Gli is non-functional.d. Their Shh is non-functional.e. Their Slimb cannot bind to smoothened.20. Wh

35、ich of the following families of molecules plays a central role BOTH in sex determination AND in axis formation of the limb bud?a. TGFb. FGFc. IGFd. Hedgehoge. WNT21. The formation of one differentiated cell type from another is a process known as transdifferentiation. Which of the following is the

36、predominant mechanism of transdifferentiation?a. Selective gene deletionb. Segregation of allelesc. Differential gene expressiond. Independent assortment of chromosomes e. Expression of the differentiation gene22. In Intimations of a Creature, Matthew P. Scott contrasts the conservation of Hox genes

37、 in many species with the diversity of body plans that exist today. Which of the following is NOT a mechanism he proposes to explain how such genetic conservation and phenotypic diversity coexist? a. The expression of the Hox genes is regulated differently in different species.b. Convergent evolutio

38、n produced genetic similarities that subsequently diverged in different species.c. Downstream responses to Hox gene products differ among species.d. Some ancestral creature possessed Hox gene precursors that acquired changes in different species.e. Transposable elements relocated the DNA binding sit

39、es of Hox gene products in different species.23. You extract 3 different cell types (A, B and C) from a mouse. Each of these cell types expresses a different cell-surface cadherin (A-cad, B-cad and C-cad). You shake up the cells and let them segregate naturally. You find that all of the A cells clum

40、p together as a ball in the center of your dish, surrounded first by a ring of B cells, then by a ring of C cells. You add a chemical that inactivates B-cad, and repeat the procedure above. Which of the following do you see?NORMAL: A B C EXPERIMENT:a. b. c. A B C A C B A Cd. e. A C A BB cells scatte

41、redthroughoutB cells scattered ondishC cellsscattered on dish24. You are a developmental biologist working on limb formation in the beloved Nikwark (a newly discovered mammal). To understand Nikwark limb development, you perform the following experiment: you transplant the AER of a forming arm bud o

42、nto another region of the main body. Which of the following do you observe?25. Which of the following treatments would produce lordosis behavior in adult rats that were spayed/neutered during infancy?a. Treatment of a female rat with testosterone during infancy and estrogen during adulthoodb. Treatm

43、ent of an infant female rat with estrogenc. Treatment of a male rat during adulthood with estrogend. Treatment of a male rat with testosterone during infancy and adulthoode. Treatment of a male rat with estrogen during infancy and testosterone during adulthood 26. Which of the following acts as an e

44、ndocrine signal?a. Cytokines released by a T helper cellb. Testosterone released from the testes of a pubescent malec. SRY gene expression in the embryonic genital ridgesd. Sonic Hedgehog released from the notochorde. IGF-1 released by chondrocytes during a pubertal growth spurt27. The following lis

45、t includes six landmarks of human development. Please choose the sequence that represents the order in which these landmarks are reached.I. Establishment of the anterior-posterior axis of the bodyII. Completed differentiation of the bipotential gonad into an ovary or testisIII. Ossification of the f

46、etal skeletonIV. Maturation of the lungsV. Completed sexual differentiation of male or female external genitalia VI. Commencement of the fetal heartbeata. I III IV II V VIb. I III II V IV VIc. I III II V VI IVd. I VI II III V IVe. I VI V II III IV28. All of the following events are important stimuli

47、 leading to parturition EXCEPT:a. Release of oxytocin by the pituitary glandb. Inhibition of hypothalamic activity by increased uterine stretchingc. Increased secretion of corticotropin releasing hormone by the placentad. Pressure of the infants head on the uterine wallse. Increased estrogen:progest

48、erone ratio in the maternal bloodstream29. Achondroplasia is a congenital disorder, caused by a mutated FGF receptor (FGFR 3). Which step in the process of endochondral ossification is prematurely terminated by the mutated FGF receptor?a. Differentiation of mesenchyme cells into osteoblasts b. Diffe

49、rentiation of mesenchyme cells into chondrocytesc. Differentiation of chondrocytes into osteocytes d. Proliferation of chondrocytese. Hypertrophy of chondrocytes30. Which of the following neural and cognitive changes is NOT associated with normal aging in human beings?a. Delay in recalling stored me

50、moriesb. Increase in crystallized intelligencec. Gradual loss of stored memoriesd. Slow and steady decline in brain weighte. Delay in storing new memories31. Which of the following cells would you expect to divide the greatest number of times in culture?a. A liver cell from an adult tortoiseb. A fib

51、roblast cell from an infant chickenc. A neuron from an infant tortoised. A hematopoietic stem cell from an adult chickene. A fingernail clipping from Leonard Hayflick32. Non-accidental death in human beings is characterized by all of the following phenomena EXCEPT:a. Refusal of food and drinkb. Lack

52、 of desire to get out of bedc. Waning consciousnessd. Shortness of breath and the “rattle of death”e. Increased activation of apoptotic pathways33. Which of the following treatments for depression generally brings about the promptest therapeutic response?a. psychological counselingb. electroconvulsi

53、ve therapyc. selective serotonin reuptake inhibitorsd. tricyclic antidepressantse. monoamine oxidase inhibitors 34. The only people in the United States with a right to medical care are:a. prisoners.b. homeless people.c. pregnant women.d. infants.e. senior citizens.35. Which of the following is a sy

54、mptom that often exists in episodes of mania AND depression?a. inflated self-esteemb. consistent fatiguec. insomniad. indecisivenesse. pleasure-seeking behavior36. You want to use the measurement of corollary discharge as a diagnostic test for a schizophrenic patient who experiences auditory halluci

55、nations. During speech production and listening, you expect this patient to exhibit:a. ERPs that are very similar during both speech production and listening.b. ERPs with a dampened N1 component during speech production.c. ERPs with a dampened N1 component during listening.d. ERPs with a larger P1 c

56、omponent during speech production.e. ERPs with a larger P1 component during listening.Short Answer Questions (102 points) Please put away your scantron and take out a non-erasable blue or black pen. Please answer the following short answer questions in the space provided. Please do not exceed the sp

57、ace provided to answer your question. Answers that exceed the allotted space will not be graded. Please write only one line of writing per allotted line. Question 1 (21 points)A. (6 points) You are a doctor at an infertility clinic and a couple comes in for advice. The woman is affected by a genetic

58、 disease which is caused by a mutant gene in the mitochondrial genome. It is of utmost importance to the couple to conceive a child who is genetically related to at least one of the parents and who will not be affected by this disorder. You think back to the artificial reproductive technologies you

59、learned about in the Core and devise two procedures through which you might help this couple realize their wish. 1. An offspring genetically related to the mother could be produced by cloning. Please detail the exact procedure by which you could accomplish this, starting with a somatic cell from the

60、 mother and finishing with a 2-celled zygote. _2. An offspring genetically related to both parents could be produced through transferring the combined genetic material from both parents into an enucleated donor oocyte. a.You begin by isolating the couples gametes and then use ICSI to achieve fertili