Unit 3 Crash Course GTAGTAGGT What would be the sequence of bases of - PDF document

4/19/2011 Unit 3 Crash Course GTAGTAGGT What would be the sequence of bases of an mRNA • Genetics molecule that was transcribed from the sequence of DNA bases shown above? A. GTAGTAGGT B. CAUCAUCCA C. UCGUCGUUC • Initial questions are worth 1 point each. D. AUGAUGAAU • Each question will be followed by an explanation E. CATCATCCA • All questions will be asked a second time at the very end, each of those questions will be worth 2 points. 0% 0% 0% 0% 0% 1 2 3 4 5 Which of the following is an enzyme used during DNA replication can be described as replication to attach Okazaki fragments to each other (A) DNA ligase A. semiconservative (B) DNA polymerase B. conservative (C) RNA polymerase C. degenerative (D) Restriction enzyme D. dispersive (E) Reverse transcriptase E. radical 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 DNA Replication Which of the following is an enzyme used to • Enzymes involved: position nucleotides during DNA replication • Helicase ‐ Unzips • Primase ‐ Adds RNA primer (A) DNA ligase • Polymerase I ‐ Removes RNA and inserts DNA (B) DNA polymerase • Polymerase III ‐ Adds nucleotides to 3’ • Ligase ‐ Joins Okazaki Fragments k k (C) RNA polymerase • Topoisomerase ‐ Prevents overwinding (D) Restriction enzyme • Leading strand vs Lagging Strand (E) Reverse transcriptase • A � T, G � C • Eukaryotic cells have Introns (inert) and Exons (expressed) 0% 0% 0% 0% 0% 1 2 3 4 5 1

4/19/2011 The replacement of glutamic acid by valine at a specific Which of the following terms refers to both the movement of a position in the beta chains of hemoglobin leads to sickle cell ribosome along a piece of mRNA and the movement of a piece anemia. This change represents which of the following of one chromosome to another chromosome? mutational events? A. DNA base pair substitution (A) Transduction B. DNA base pair deletion ( ) (B) Transgenesis g C. DNA base pair addition (C) Transformation D. Chromosomal deletion (D) Translocation E. Frame shift mutation (E) Transplantation 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 DNA Mutations ABCDEF… � ABDEF... A rearrangement in linear sequence of genes as shown in the • Substitution ‐ One nucleotide is replace with diagram above is known as: another, no frame shift A. duplication • Deletion, Insertion ‐ Often result in frame shift B. deletion • Transposition ‐ movement of whole segments C. inversion • Transposons ‐ Jumping genes D. polyploidy E. translocation 0% 0% 0% 0% 0% 1 2 3 4 5 A diploid cell has three pairs of homologous The primary value of a specific type of backcross chromosome designated J1/J2, K1/K2 and L1/L2. Which known as a test cross is to of the following represents a probable chromosome complement in a haploid cell formed by meiosis? A. determine whether a trait is really A. J1 and K1 hereditary B. J1 and J2 B. permit detection of recessive B permit detection of recessive C. J2, K1, and L2 genes D. J1, J1, K2, and K2 C. reveal cases of blending inheritance E. J1, J2, K1, K2, L1, and L2 D. reveal remote ancestors E. reveal sex ‐ linked inheritance 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 2

4/19/2011 A form of vitamin D ‐ resistant rickets, known as Mendelian Inheritance hypophosphatemia, is inherited as an X linked dominant trait. If a male with hypophosphatemia marries a normal female, • Law of segregation ‐ homologous chromosomes which of the following predictions concerning their potential separate in meiosis progeny would be true? • Law of independent assortment ‐ the way one allele segregates has no change on others A. All of their sons would inherit the disease. • Complete Dominance ‐ one allele shows, other does not B All of their daughters would inherit B. All of their daughters would inherit the disease. • Incomplete Dominance ‐ dominant trait may be less apparent (red+white � pink) C. About 50% of their sons would inherit the disease. • Co ‐ dominance ‐ Both traits are 100% expressed D. About 50% of their daughters would • Homozygous ‐ AA or aa, Heterozygous ‐ Aa inherit the disease. • Epistasis is the control over one locus by another E. None of their daughters would inherit • Sex Linked Traits are found on the X chromosome the disease. 0% 0% 0% 0% 0% 1 2 3 4 5 The relative location of four genes on a Which of the following can be diagnosed by chromosome can be mapped from the following examining a karyotype of an individual's white data on crossover frequencies. blood cells? (A) Sickle cell anemia Which of the following represents the relative positions of these four genes on the chromosome? (B) Alzheimer disease (C) Down syndrome A. ABCD (D) Cystic fibrosis B. ADCB (E) Duchenne muscular dystrophy C. CABD D. CBAD E. DBCA 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 A spermatocyte produces the following four sperm cells. Meiosis • 1 diploid becomes 4 unique haploid • Crossing over occurs in prophase 1 • Genes are more likely to be inherited together if they are close together (gene loci) These cells are the result of nondisjunction during which of These cells are the result of nondisjunction during which of • Nondisjunction can occur in anaphase 1 or the following phases? anaphase 2 (A) Interphase (G1 or G2) • Down syndrome ‐ trisomy 21 (B) Interphase (S) (C) Mitosis (D) Meiosis I (E) Meiosis II 0% 0% 0% 0% 0% 1 2 3 4 5 3

4/19/2011 In fruit flies, vermilion eyes are a sex ‐ linked recessive What is the probability that the genotype Aa will be characteristic. If a vermilion ‐ eyed female is crossed produced by the parents Aa x Aa with a wild ‐ type male, what proportion of the male offspring should have vermilion eyes? (A) 0 A. 0% (B) 1/16 B 25% B. 25% (C) 1/4 C. 50% (D) 1/2 D. 75% (E) 3/4 E. 100% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 Laws of Probability What is the probability that the genotype ccdd will • Law of multiplication – probability of 2 events be produced by the parents CcDd x CcDd occurring is the product of each probability (A) 0 • Monohybrid cross ‐ Aa x Aa 1:AA 2:Aa 1:aa probability: 75% dominant 25% recessive (B) 1/16 • Punnett squares are useful in determining P tt f l i d t i i (C) 1/4 probability (D) 1/2 A a (E) 3/4 A AA Aa homozygous heterozygous Aa aa a heterozygous homozygous 0% 0% 0% 0% 0% 1 2 3 4 5 Protein Synthesis Analysis of DNA sequences from two individuals of the same species results in a greater estimate of genetic variability than docs analysis of • Transcription factors ‐ activate promotor amino acid sequences from the same individuals because • Transcription ‐ DNA to mRNA (A) different DNA sequences can code for • mRNA modification ‐ Alternate splicing, G ‐ cap, the same amino acid poly A tail (B) some amino acid variations cannot be d detected by protein electrophoresis d b l h • Translation ‐ mRNA to amino acid sequence (C) DNA sequencing is a more reliable • tRNA matches codons to amino acids technique than protein electrophoresis • rRNA makes up ribosomes (D) proteins are more easily damaged than is DNA • Post ‐ translational modifications: (E) DNA is more heat ‐ sensitive and therefore phosphorylation and cleavage varies more 0% 0% 0% 0% 0% 1 2 3 4 5 4

4/19/2011 Refer to the following pedigree that Refer to the following pedigree that illustrates the inheritance of sickle cell illustrates the inheritance of sickle cell anemia. Shading indicates the presence anemia. Shading indicates the presence of sickle cell anemia. of sickle cell anemia. The most reasonable explanation for the What is the probability that the next fact that the offspring of C and D do not child of parents A and B would have had have sickle cell anemia is that each sickle cell anemia? sickle cell anemia? received a A. sickle allele from the mother A. 0% B. normal allele from the father B. 25% C. sickle allele from each parent C. 60% D. normal allele from each parent D. 75% E. pair of normal alleles from the E. 100% father 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1 2 3 4 5 1 2 3 4 5 Pedigrees Refer to the following pedigree that illustrates the inheritance of sickle cell • Used to determine heritage anemia. Shading indicates the presence of sickle cell anemia. • Shows sex ‐ linked traits, dominant vs. recessive • Females are circle, males are square Which of the following statements is correct about the four offspring of C and D? A. Only the females are carriers of the sickle A O l h f l i f h i kl cell trait. B. Only the males are carriers of the sickle cell trait. C. Only the females are heterozygous for the sickle cell trait. D. All are homozygous for the sickle cell trait. E. All are carriers of the sickle cell trait. 0% 0% 0% 0% 0% 1 2 3 4 5 A form of vitamin D ‐ resistant rickets, known as Review Quiz! hypophosphatemia, is inherited as an X linked dominant trait. If a male with hypophosphatemia marries a normal female, which of the following predictions concerning their potential •Answer values are doubled… lets progeny would be true? see how you do. A. All of their sons would inherit the disease. B. All of their daughters would inherit B All of their daughters would inherit the disease. C. About 50% of their sons would inherit the disease. D. About 50% of their daughters would inherit the disease. E. None of their daughters would inherit the disease. 0% 0% 0% 0% 0% 1 2 3 4 5 5