Questions 1-20. Multiple Choice: 1.5 points each. Select the Best Answer. Circle your answer here and fill in your bubble sheet. This portion of the exam will be graded using the bubble sheets only. Question 1 is based on the following information. Male-pattern baldness is a sex-linked trait in which affected people become bald. XB = No baldness (dominant) Xb = Male-pattern baldness (recessive) If a Male with XbY genotype mated with a Female with XB Xb genotype. 1. What percent of male children will have male-pattern baldness? a. 25% c. 75% e. 0% b. 50% d. 100% 2. If a male WITHOUT male-pattern baldness is mated to a female WITH male-pattern baldness, what is the probability that they will produce a male child WITH male-pattern baldness? a. 25% c. 75% e. 0% b. 50% d. 100% Question 3. Answer question 3 based on the following information. You will need to draw and complete a Punnett Square to answer question 3. Fur color in Labrador Retrievers is a Polygenic trait with Epistasis. There are two genes and two alleles for each gene: Gene 1: B = Black coat (dominant) b = Brown coat (recessive) Gene 2: T = Add pigment to fur (Dominant) t = No pigment (Recessive) (Yellow) Mate two retrievers with these genotypes: Male BbTt x Female bbTt 3. From the cross above, what is the probability of having a Brown Labrador Retriever puppy? a. 12.5% c. 50.0% e. 62.5% b. 37.5% d. 0% 4. Which of the following is always true about a Polygenic trait? a. Has a phenotype distribution that is normally distributed (bell-shaped curve) b. A good example is human height c. Is a trait controlled by more than one gene d. All of the above are correct e. None of the above are correct 5. In a double-stranded DNA molecule, _____ hydrogen bonds hold A and T bases together, while _____ hydrogen bonds hold G and C bases together. a. 2, 3 c. 3, 2 e. 2, 1 b. 1, 2 d. 3, 4 6. The Cystic Fibrosis gene affects several different phenotypes including reproductive ducts, salivary ducts, and lachrymal ducts (tears). What term do we use to describe a gene that affects multiple phenotypes? a. Autosome c. Pleiotropy e. Co-dominance b. Incomplete dominance d. Epistasis 7. Which term describes the genetic condition of inheriting an XXY genotype? a. Turner’s syndrome c. Klinefelter’s syndrome e. Familial aneuploidy b. Trisomy X d. Down syndrome Name ________________________ Biol 1102 Exam 3, Fall 2011 8. Which term describes when a cancer spreads to other parts of the body? a. MPF c. Apoptosis e. Metastasis b. Oncogenesis d. Benign 9. During development, what process forms the spaces between your fingers? a. Metastasis c. Oncogenesis e. Apoptosis b. Regeneration d. Acrosomal division 10. Which of the following is a normal gene involved in starting mitosis? a. Oncogene c. Proto-oncogene e. Melanoma b. Myostatin d. Neoplasm 11. Which of the following is a collection of dead white blood cells (pus)? a. Abcess c. Uterine fibroid e. Melanoma b. Cyst d. Sarcoma 12. BRCA1 and BRCA2 are alleles for which types of genes? a. Receptor proteins c. Cyclin proteins e. Signaling molecules b. Mitosis promoting d. Tumor-suppressor 13. Which gene is considered a negative regulatory protein because it is responsible for blocking the expression of genes on the X chromosome and allowing 'maleness' to develop? a. Testosterone c. SRY e. Androgen b. Estrogen d. Prostatin 14. Crocodiles and Alligators have environmental sex determination. What factor directly controls whether a crocodile or alligator will be male or female? a. Environmental toxins (PCB) c. Social environment e. Genes control sex b. Temperature d. Daylength 15. Which of the following results in the production of offspring from unfertilized eggs? a. Budding c. Fragmentation e. Mitosis b. Parthenogenesis d. Binary Fission 16. What do we call the situation where different cells in the body express different genotypes and all the cells are derived from the same fertilized egg? a. Chimera c. Gynandromorph e. Mosaic b. Diandry d. Protandry 17. What do we call the situation where different cells in the body express different genotypes and the cells are derived from different fertilized eggs? a. Chimera c. Gynandromorph e. Mosaic b. Diandry d. Protandry 18. What term do we use when chromosomes do not segregate equally? a. Aneuploidy c. Non-disjunction e. Mosaicism b. Trisomy d. Crossing over 19. The term Dosage Compensation refers to which chromosomes? a. Autosomes b. Sex chromosomes 20. Which definition of anticodon is correct? a. The anticodon is the mRNA complement to the tRNA codon b. The anticodon is the tRNA complement to the mRNA codon c. The anticodon is the rRNA complement to the mRNA codon d. The anticodon is the mRNA complement to the rRNA codon 1 Name ________________________ Biol 1102 Exam 3, Fall 2011 Questions 21 – 50. Short answer questions: Note: many questions have more than one part. Write neatly so I can give you credit! To save time, do not re-write the question in your answer. Short IS sweet! You will lose credit for wrong answers so do not write extra information that you are unsure about! 21. (2 pts.) Briefly describe how Androgen Insensitivity Syndrome is produced. Mutation in the androgen receptors on target cells prevents cells from receiving ‘male’ signals and allows female characteristics to develop. 22. (2 pts.) Briefly explain Dosage Compensation. Genetic mechanisms that equalize the expression of X-linked genes in males and females 23. (4 pts.) Based on our discussion, how are genes regulated? Draw and label the picture from class. (4 parts)A regulatory protein binds to the promoter region of a gene. A positive regulatory protein has a shape that allows RNA polymerase to bind to it and initiate Transcription. A negative regulatory protein has a shape that does not allow RNA polymerase to bind to it and so prevents Transcription from occurring. 24. (4 pts.) Why do many DNA mutations have no affect on the phenotype? Use an example from the codon table if it helps you explain. Because many mutations are 'silent', occurring at the third position of the codon, which does not change the amino acid in the protein. 25. (1.5 pts.) Explain why an XXX genotype may not cause any problems for a human female. Human females have X-chromosome inactivation anyway so the extra X is shut off with the regular X and leads to a normal female phenotype. 26. (1.5pts.) Explain why an XYY genotype may not cause any problems for a human male. Few genes on Y chromosome and most involve maleness so the extra Y has limited effect. 27. (1 pt.) Why do some bacteria make restriction enzymes? Bacteria use restriction enzymes to kill invading viruses. 28. (1 pt.) How are Fraternal Twins produced? Two different egg cells are fertilized at the same time in the same female 29. (1 pt.) How are Identical Twins produced? A fertilized egg cell divides into two cells and each one develops independently 30. (2 pts.) Humans typically have one baby at a time. Why do some animals have multiple offspring at a time? A way to ensure that at least one offspring survives in a variable environment 2 Name ________________________ Biol 1102 Exam 3, Fall 2011 31. (2 pts.) What is the difference between a Benign and a Malignant tumor? A benign tumor does not spread, a malignant tumor does. 32. (1 pt.) What enzyme unzips the DNA molecule prior to DNA replication? Helicase 33. (1 pt.) What Enzyme re-zips the DNA molecule after DNA replication? DNA Polymerase 34. (1 pt.) What term describes that each new DNA molecule is made from one new DNA strand attached to one old DNA strand? Semi-conservative replication 35. (1 pt.) What is the contractile ring made from? The protein Actin 36. (1 pt.) Where else can you find this protein in an animal's body? Muscles 37. (4 pts.) List the four processes that produce genetic variation among gametes. a. Mutation b. Segregation of alleles c. Recombination d. Independent Assortment 38. (2 pts.) What is a Cancer? Uncontrolled mitosis (cell division) 39. (2 pts.) Fill in the two blanks. Breast_______ cancer is the most common female cancer. Prostate_______ cancer is the most common cancer in males. 40. (2 pts.) The most common cancer that affects both males and females? Lung cancer / Skin 41. (4 pts.) What are the four general treatment options or ways that people can fight Cancer? a. Immune System b. Radiation c. Surgery to remove cancer d. Chemotherapy 42. (1 pt.) Matching. Draw lines matching the word on the left with the treatment on the right Mastectomy Removal of uterus Oophorectomy Removal of ovaries Orchidectomy Removal of testis Hysterectomy Removal of breasts 43. (1 pt.) Circle the cancers: Melanoma, Uterine fibroid, Cyst, Abscess, Fibroadenoma, Carcinoma 44. (2 pts.) As given in class, what are two reasons why sex-linked traits are important? a. Phenotypes are more common in males than females b. Females can be carriers 45. (1 pt.) What structure prevents two sperm from fertilizing an egg? Fertilization membrane 46. (3 pts.) Name one of the two cancer vaccinations from class. (Hint: you are naming the antigen). Alpha-Lactalbumin for Breast Cancer or Prostatic Acid Phosphatase for Prostate Cancer 3 Name ________________________ Biol 1102 Exam 3, Fall 2011 47. (1 pt.) Using the definition given in class, what is a gene? Piece of DNA that codes for a protein with a start and stop codon. 48. (1 pt.) Explain what it means to say that a gene is expressed. It means that the gene has gone through transcription and translation to make a protein 49. (2 pts.) Explain phenotypic plasticity. The ability of an organism with a given genotype to change or modify its phenotype in response to changes in the environment. 50. (1 pt.) Give three examples from class of human phenotypes that are plastic. Musculature / Weight / Skin color There are no diagrams on the OCLF. 4