Principles of Biology I Exam III, Fall ‘05
Name:_____________________________
Read all of the possible answers for each question before choosing the BEST ANSWER. 1. Mendel chose two two true true breeding breeding cultiva cultivars rs of the pea for an an experiment experiment.. One had purple flowers and the other white. Later, when he had completed his experiment and was recording the results, these two cultivars would be called: a. the the parent parental al (P) (P) gen gener erat atio ion. n. b. b. the the firs firstt fil filia iall (F1) generation. c. the the sec secon ond d fil filia iall (F (F2) generation. d. hyb hybrids. e. gener neration X. X. 2. The height height of a human human male male seems to vary widely with no no obvious obvious individual individual phenotypes (individuals can be found that represent virtually all different heights over a rather wide range). This is primarily an example of the phenomenon called: a. conti continuo nuous us varia variati tion. on. b. b. epis epista tassis. c. plei pleiot otrrophi ophism sm.. d. inde indepen penden dentt asso assort rtme ment nt.. e. envi enviro ronm nmen ental tal effe effect cts. s. 3. The chromosom chromosomal al theory theory of inheri inheritance tance is commonly commonly attribute attributed d to: a. Mendel. b. Sutton. c. Chargaff. d. Mess Messel elso son n and Stah Stahl. l. e. Morgan. 4. The arctic arctic fox has a white white fur coat in the winter winter but a reddish reddish brown brown coat in in the summer. summer. This is an example of: a. conti continuo nuous us varia variati tion. on. b. b. epis epista tassis. c. plei pleiot otrrophi ophism sm.. d. incom incompl plet etee domin dominanc ance. e. e. envi enviro ronm nmen ental tal effe effect cts. s. 5. The ultimate ultimate source/m source/mechani echanism sm for the the introductio introduction n of new alleles alleles into into a species species is: a. gene fl flow. b. b. foun founde derr effe effect cts. s. c. hyb hybridiz idizat atiion. on. d. gene geneti ticc dri drift. e. mutation.
6. A time time traveler traveler has has brought brought Mendel “back “back to the future future”” and he has now accepted accepted a position at UNT. UNT. He decides to continue his work and begins by performing a dihybrid cross for pea pod shape and plant height. These are the two loci are located very close to each other on chromosome four and therefore do not assort independently during meiosis. meiosis. Unfortunately Mendel does not keep up with the literature and doesn’t know this. If he properly interprets his new results, results, Mendel will now rediscover: a. epistasi asis. b. cros crosso sove verr fixat fixatio ion. n. c. linkage. d. codo codom minanc nance. e. e. why he never never perf perform ormed ed this this cross cross in the the 1800’ 1800’s.. 7. Humans cannot tolerat toleratee a variable variable number number of chromos chromosomes omes in in a developing developing embryo and yet the male embryo has one o ne X chromosome and the female has two. The X chromosome is also large and carries many genes. We now know that the female cells compensate for this problem by forming a/an: a. autosome. b. centr ntriole. c. nucle cleosome ome. d. Barr body. dy. e. incl inclus usio ion n body body.. 8. A human human femal femalee with with the karyo karyoty type pe XO will: will: a. have have Kli Klinef nefel elte terr synd syndrom rome. e. b. have have Tur Turner ner syndr syndrome ome.. c. be normal normal since since the second second X chromosome chromosome isn’t isn’t used used anyway anyway.. .. d. have have Dow Down n synd syndro rome me.. e. None of the above are true true since since monosomic monosomic chromosom chromosomes es are fatal fatal before before birth. 9. Mendel proposed proposed a Law of Independen Independentt Assortment Assortment.. Today we would would call the units that he hypothesized to assort independently: a. alleles. b. b. homo homozy zygo gottes. es. c. genes. d. cultivar vars. e. filials. 10. Another Another term for reproductive reproductive success is: is: a. natu natura rall sel selec ecti tion on.. b. b. epis epista tassis. c. syngamy. d. fitness. e. prot protot otro roph phy y.
11. Recently one of the Martian rovers stumbled across the remains of that planet’s planet’s library of natural history. history. One of the books describes the evolutionary processes that lead to a now extinct, ex tinct, long-legged animal translated as the akfar. The ancestors to the akfar apparently received painful scratches on their underbellies from a very thorny bush then common on the planet. Clearly the animals had to stretch their legs to the maximum to avoid this painful experience. The book goes on to describe the fossil record leading to the akfar and explains the progressively longer legs of each succeeding generation as resulting from the passing on the stretched legs (longer from all of the stretching) of the parents to the offspring which in turn stretched them further before passing the even longer legs on to the next generation. This Martian theory is is very similar to an explanation for the process of evolution described by: a. Wallace. b. Lamarck. c. Sutton. d. Flemming. e. Darwin. 12. In a stable population of individuals, the allele frequencies frequencies should remain relatively constant if certain conditions are met. This is the: a. HardyHardy-W Weinber einberg g princi principle ple.. b. theory theory of natura naturall sele selecti ction. on. c. theo theory ry of evo evolu luti tion on.. d. firs firstt law law of Mend Mendel el.. e. seco second nd law law of Mend Mendel el.. 13. The sickle cell allele is lethal in the homozygote state, state, but the same allele in heterozygote form provides resistance resistance to malaria. This is an example of: a. inde indepen penden dentt asso assort rtme ment nt b. heter heterozy ozygot gotee advan advanta tage ge c. homozy homozygot gotee defic deficie iency ncy d. frequen frequency cy-dep -depend endent ent select selection ion e. cros crossi sing ng over over 14. A population of flowers flowers under study has a range of colors from white to pink to dark red. In this case red, pink pink and white are all the phenotypic phenotypic result of separate alleles at the flower color locus. Deer prefer to eat pink flowering plants to the point where the numbers of pink plants are severely and continuously reduced in the population. Eventually this yields yields a population where red and white are common colors but pink plants are are almost never found. This would be an example of: a. stab stabil iliz izin ing g sele select ctio ion. n. b. dire direct ctio ional nal sel selec ecti tion. on. c. disr disrup upti tive ve sele select ctio ion. n. d. rand random om sele select ctio ion. n. e. frequen frequency cy-dep -depend endent ent select selection ion..
15. Millions of years years ago the sole surviving herd of triceratops was astronomically astronomically reduced (struck by a sizeable asteroid, reducing it to only 10 members). However, the number of these reptiles rebounded over time and the species once again become common (until a bad experience with an even larger asteroid). Given these facts, a modern study of genetic gene tic diversity in the DNA of post-asteroid triceratops (recovered from blood sucking insects preserved in amber) might be expected to reveal that from the point of population genetics, these reptiles experienced: a. natu natura rall sel selec ecti tion on.. b. dire direct ctio ional nal sel selec ecti tion. on. c. the the bottl bottlen enec eck k eff effec ect. t. d. dive divers rsif ifyi ying ng sele select ctio ion. n. e. one one of tho those se ver very y bad bad hair hair day days. s. 16. Which of the following is NOT required to maintain Hardy-W Hardy-Weinberg einberg equilibrium? a. random ma mating b. b. no migra igrati tion on c. no mutati ation d. lar large popu popula lati tion on size size e. All of the the above are require required d to maintain maintain Hardy-W Hardy-Weinber einberg g equilibrium equilibrium.. 17. The average birth birth weight of a human baby is 6-7 pounds. Babies with substantially higher or lower birth weights have a much higher infant mortality rate (lower survival). This is an example of: a. epistasi asis. b. disr disrup upti tive ve sel select ectio ion. n. c. dire direct ctio ional nal sele select ctio ion. n. d. stab stabil iliz izin ing g sele select ctio ion. n. e. the the bottl bottlen enec eck k eff effec ect. t. 18. A person is determined to have a blood type of AB. At this locus this person is a: a. dihybrid. b. zyg zygote. c. homo omozyg zygote ote. d. hete heterrozy ozygot gote. e. hete heterrokar okary yon. on. 19. A red flowered plant is crossed with a white flowered plant. Flower color in this particular plant exhibits incomplete incomplete dominance. The fraction of pink plants in in the F1 generation would be expected to be: a. 0/4) (z (zero). o). b. 1/4. c. 2/4 (50%). d. 3/4. e. 4/4 (1 (100%).
20. Alternative forms of a character (e.g. round vs. wrinkled wrinkled peas) are called: a. genes. b. hyb hybrids. c. hete heterrozy ozygot gotes. es. d. alleles. e. filials. 21. Genes located on the same chromosome are said to be: a. polygenic. b. b. bott bottllenec enecke ked. d. c. plei pleiot otrropic opic.. d. linked. e. epistati atic. 22. The expression of human blood groups ia ia an example of the genetic phenomenon known as: a. epistasi asis. b. b. pleo pleottropi ropism sm.. c. incom incompl plet etee domin dominanc ance. e. d. codo codom minanc nance. e. e. conti continuo nuous us varia variati tion. on. 23. A homozygous dominant plant (PP) is crossed with a homozygous recessive plant (pp). The F1 generation is then self-crossed self-crossed to produce the F2 F2 generation. The phenotypic or Mendelian ratio of the offspring will be: a. 1:3 b. 3:1 c. 9:3:3:1 d. 9:7 e. 2:2 An example of a human hu man genetic disorder involving a male with a Barr body is: a. Klin Klinef efel elte terr syndr syndrome ome.. b. b. Down Down synd syndro rome me.. c. Hunt Huntin ingt gton on dis disea ease se.. d. Turne urnerr syn syndr drom ome. e. e. musc muscula ularr dyst dystro rophy phy..
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25. A human gene is said said to be sex-linked sex-linked if: a. it is is more more commo common n in fema females les than than males males.. b. it is is found found on the the “Y” “Y” chro chromos mosome. ome. c. it is found found on on the the “X” “X” chromo chromosom some. e. d. it is expres expressed sed only in male males. s. e. it is reces recessi sive ve in in mal males es..
26. An allele at one locus affects affects several phenotypic traits traits (e.g. cystic fibrosis fibrosis is caused by a single defective gene which causes clogged blood vessels, sticky mucus, salty sweat, liver failure, etc.). This is an example of: a. conti continuo nuous us varia variati tion. on. b. b. codo codom minanc nance. e. c. inco incomp mple lete te domi domina nanc ncee d. epistasi asis. e. plei pleiot otro ropi picc effe effect cts. s. The red flower allele exhibits incomplete dominance over the white flower allele. Using the Hardy-Weinberg Hardy-Weinberg equation (p2 + 2pq + q2 = 1), if the frequency of the red allele in a population is 0.8, and the frequency frequenc y of the white allele is 0.2, what is the fraction of plants that will have pink flowers? a . 4% b . 8% c. 16% d. 32% e. 64%
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28. If you listen in lecture, according to Dr. Dr. Benjamin, that hemophilia in the European royal families is a clear example of: a. incom incompl plet etee domin dominanc ance. e. b. mult multig igeni enicc inheri inherita tance nce.. c. epistasi asis. d. gene geneti ticc warf warfar are. e. 29. Which of the following properties properties are NOT properties properties of the presently accepted (Watson (W atson and Crick) model for DNA structure? a. Nucleot Nucleotide idess are connect connected ed by phosph phosphodi odiest ester er bonds. bonds. b. The two two stran strands ds are are complem complement entary ary.. c. Adeni Adenine ne pair pairss with with cyto cytosi sine. ne. d. The two strands strands are antipa antiparal rallel lel.. e. All of the above above are correctly correctly stated stated properties properties of of the present present model. 30. The process of DNA replication is said to be carried out in a semiconservative semiconservative manner. This means means that: a. although although the individual individual nucleoti nucleotides des of a strand strand are are held together together by covalent bonds, the two strands of the duplex are held together by weak, easily broken bonds. b. only half half of the the DNA is passed passed on to to the next next generation, generation, with the the remainder being discarded as heterochromatin. c. some of the DNA DNA is replaced replaced by RNA during replication replication.. d. base pairing pairing rules rules change change each each purine purine position position to a pyrimidine pyrimidine,, and vice vice versa, during the replication process.. e. each daughter daughter duplex has one one of the the parental parental duplex strands strands passed passed on to it.
31. The semidiscontinuous nature of the the DNA replication process was discovered by: a. Watso atson n and and Cric Crick. k. b. Mess Messel elso son n and and Stah Stahl. l. c. Chargaff. d. Okazaki. e. Gurdon. 32. The 3’exonuclease activity of a DNA DNA polymerase is used for: for: a. proo proofr frea eadi ding ng.. b. b. nick nick tra trans nsla lati tion on.. c. synthes hesis. d. mobility. ty. e. All of the the above above are depend dependent ent upon upon this this activit activity y. 33. The protein which binds to single-stranded single-stranded DNA to keep it protected and to prevent base pairing is called: a. gyrase. b. helicase. c. SSB. d. replicas case. e. ligase. 34. The enzyme responsible for primer primer removal during DNA replication in E. coli is called: a. helicase. b. gyr gyrase. c. DNA DNA poly polyme mera rase se I. d. DNA DNA polym polymer eras asee III III.. e. DNA ligas gase. 35. A pea plant is determined to be Aa at a certain locus. In this case Aa is considered to be its: a. phenotype. b. genoty notype pe.. c. filial. d. hyb hybrid makeu akeup. p. e. Punne unnett tt squar quare. e. 36. Mendel’s first law of heredity, heredity, demonstrated/proven by the monohybrid cross data, was: a. the the law law of prob probab abil ilit ity y. b. the the law law of domin dominanc ance. e. c. the the law law of segr segrega egati tion. on. d. the the law law of inhe inheri rita tance nce.. e. the law of indepe independen ndentt asso assortm rtment ent..
37. The British doctor who observed observed that an unusual metabolic disorder was inherited in families in a Mendelian fashion and therefore made an early connection between the gene and the enzyme was: a. Tatum. b. Garrod. c. Gurdon. d. Sutton. e. Griffith. 38. During the process of making making a polypeptide, the new amino acid enters the ribosome’s: a. rbs. b. “P” site. c. “A” site. d. “E” site. e. anticodon. 39. The template used by a ribosome making a polypeptide polypeptide is called: a. an mRNA. b. a tRNA. c. an rRNA. d. an rbs. e. the sense sense stra strand nd of of the the DNA DNA duplex. duplex. 40. The sequence of nucleotides commonly found at the –10 position of an E. coli promoter is: a. TATAAT AAT. b. AAAAAA. c. TTGACA. d. cal called led the the rbs. bs. e. ATG. 41. A hairpin hairpin structure with a GC-rich stem followed by a string string of U’s U’s is commonly associated with: a. transc transcrip riptio tional nal termin terminato ators. rs. b. promot omoteers. c. the rbs. d. the the trans transcr crip ipti tion on bubb bubble le.. e. rRNA rRNA mole molecu cule les. s. 42. The process of making a polypeptide polypeptide using an RNA template is called: a. phos phospho phodi dies este terr synthe synthesi sis. s. b. b. tran transl slat atio ion. n. c. tran transc scri ript ptio ion. n. d. repl repliicati cation on.. e. transition.
43. The enzyme that eliminates primers primers during DNA replication is: a. DNA DNA poly polyme mera rase se I. b. primase. c. DNA DNA pol poly ymera merase se III III.. d. helicase. e. DNA ligas gase. 44. The codon AUG AUG in protein protein synthesis synthesis is read as: a. stop. b. start. c. an inter internal nal amin amino o acid, acid, but but not start start or stop. stop. d. rele releas asee the the poly polypep pepti tide de.. e. star startt tran transc scri ript ptio ion n here here.. 45. The region of a gene (DNA) where the RNA polymerase binds to begin gene expression is called the: a. origin. b. ribo ribosom somee bin bindi ding ng sit site. e. c. promoter. d. init initia iato torr site site.. e. P site. 46. The individual(s) who obtained the first X-ray diffraction diffraction data from DNA crystals that showed it was a helix of uniform diameter was/were: a. Watso atson n and and Cric Crick. k. b. b. Erwi Erwin n Cha Charrgaf gaff. c. Rosa Rosali lind nd Fra Frank nkli lin. n. d. P. A. Levi Levine ne.. e. Mess Messel elso son n and and Sta Stahl hl.. 47. The correct model of the structure structure of a DNA molecule was elucidated (solved) by: by: a. Fran Frankl klin in and and Wilki ilkins ns.. b. b. Linu Linuss Paul Paulin ing. g. c. Hers Hershe hey y and and Cha Chase se.. d. Erwi Erwin n Char Charga gafff. e. Watso atson n and and Cric Crick. k. 48. During DNA replication, the double helix is opened by the enzyme: a. DNA gyr gyrase ase. b. b. DNA DNA pol poly ymera merase se I. I. c. Primase. d. DNA DNA polym polymer eras asee III III.. e. helicase.
49. During DNA replication, the enzyme DNA ligase: a. connect connectss short short segmen segments ts of DNA DNA toget together her.. b. connects connects the the first first few few nucleoti nucleotides des of of each new molecul molecule. e. c. Opens Opens the the heli helix x at the repl replica icatio tion n fork. fork. d. removes removes the “over “over winding” winding” caused by the opening opening of the the DNA helix. helix. e. binds to to single-st single-stranded randed regions regions at the fork fork to keep keep them from reformi reforming ng base pairs. 50. The two strands of a DNA molecule are held together by: a. phos phospho phodi dies este terr bond bonds. s. b. ionic ionic bonds bonds between between the phosph phosphate ates. s. c. hydrop hydrophob hobic ic intera interacti ctions ons betwe between en the bases bases.. d. hydr hydrog ogen en bond bonds. s. e. ami aminoac noacy yl bond bonds. s. 51. Messenger Messenger RNAs are synthesized synthesized by: a. ribosome omes. b. b. DNA DNA poly polyme mera rase ses. s. c. RNA RNA poly polyme mera rase se.. d. promot omoteers. e. aminoa aminoacyl cyl tRNA tRNA synthe synthetas tases. es. 52. The enzymes that connect the amino acids to the tRNAs are called: a. aminoacyl aminoacyl tRNA synthetase synthetasess or activating activating enzymes. enzymes. b. promot omoteers. c. ligases. d. RNA RNA pol poly ymera merase ses. s. e. elon elonga gati tion on fac facto tors rs.. 53. A common transcriptional terminator in a bacterial system system would be: a. a GC-rich GC-rich stem structure structure followed followed by a string string of U’s U’s in an mRNA. mRNA. b. UAG. c. a tran transc scri ript ptio ion n fact factor or.. d. a rel relea easi sing ng fact factor or.. e. The seque sequence nce TAA at the the 3’end 3’end of a gene. gene. 54. A splicesome is a complex of nucleic acid and protein that: a. transc transcrib ribes es mRNAs mRNAs in bacteri bacteria. a. b. is involved involved in the process process of protein protein synthesi synthesiss (translati (translation) on) in both both prokaryotes and eukaryotes. c. ss conside considered red a transcript transcription ion factor factor found in eukaryot eukaryotes. es. d. is involved involved in in DNA DNA methylation methylation in eukary eukaryotes. otes. e. is invol involved ved in RNA RNA proc process essing ing in in eukaryo eukaryotes tes..
55. Two white-kernelled true-breeding strains strains of corn are crossed crossed and surprisingly give F1 plants that all have purple kernels. A selfing selfing of the F1 plants yields F2 generation plants that have a ratio ratio of 9 purple kernelled to 7 white kernelled. This is likely an example of: a. incom incompl plet etee domin dominanc ance. e. b. blending ding.. c. codom dominan nance. d. epistasi asis. e. plei pleiot otro ropi picc effe effect cts. s. 56. Nearly all mRNAs in eukaryotes eukaryotes end in the sequence: a. AAA200. b. UAA. c. AUG. d. TATA e. TTGACA
