BioSc 231 General Genetics Exam 4 Name __________________________________Multiple Choice. (2 points each)_____ Type of mutation in which a pyrimidine is substituted for a purineA. TransitionB. TransversionC. FrameshiftD. ConversionE. Inversion_____ Type of mutation caused by an addition or deletion of a base in a polypeptide-encodingpart of a geneA. TransitionB. TransversionC. FrameshiftD. ConversionE. Inversion_____ Type of mutation in which a purine is substituted for a purineA. TransitionB. TransversionC. FrameshiftD. ConversionE. Inversion_____ A type of microorganism that can exist on minimal mediumA. ConditionalB. LethalC. AuxotrophD. PrototrophE. Autotroph_____ A mutation that causes a mutant phenotype only under restrictive conditionsA. ConditionalB. LethalC. AuxotrophD. PrototrophE. Autotroph_____ A biochemical mutant that must be supplied with a particular nutrient for growthA. ConditionalB. LethalC. AuxotrophD. PrototrophE. Autotroph_____ A base change resulting in a codon specifying the same amino acid as found in the wild-type polypeptide.A. MissenseB. SilentC. NonsenseD. SynonymousE. Frameshift_____ A base change resulting in a codon specifying an amino acid which is different than in the wild-type polypeptideA. MissenseB. SilentC. NonsenseD. SynonymousE. Frameshift_____ A base change that changes a codon for an amino acid to a stop codonA. MissenseB. SilentC. NonsenseD. SynonymousE. Frameshift_____ After mutagen treatment, a molecule of 2-aminopurine (an adenine analogue) incorporates into DNA. During replication the 2-AP protonates caussing it to base-pair like guanine. The mutational event caused by this will be A. AT to CG B. GC to AT C. AT to TA D. AT to GC E. GC to CG_____ A researcher studying hemoglobin predicts that a histidine within the protein is important for binding oxygen. She used site-directed mutagenesis to change a codon for histidine (CAU) to one for lysine (AAA). However, the mutant hemoglobin still binds oxygen just as well as the wild-type and has no other apparent changes. This type ofmutation is calledA. suppression B. synonymous C. nonsenseD. silentE. frameshift_____ A new Penicillium mutant was tested for auxotrophy. The mutant grows on:minimal medium (M) + arginine (A) + proline (P)M + P + histidine (H)M + A + H + Pbut not on Mor on M + A + H. The mutant requiresA. Arginine B. Histidine and prolineC. Histidine D. Arginine and prolineE. Proline_____ A bacterial histidine mutant was plated on minimal medium. A single colony grew. Thiscolony must have arisen from aA. forward mutation B. suppressor mutationC. auxotrophic mutation D. back mutation E. back mutation OR suppressor mutation_____ A mutant allele of corn leads to absence of red anthocyanin pigment in the kernel (absence of anthocyanin results in a yellow color). The allele, however, is unstable, reverting quite late, yet often, in development. The expected phenotype of kernelshomozygous for this mutation is A. fully red B. yellow with many large red spots C. yellow with few large red spotsD. yellow with many small red spotsE. yellow with few small red spots_____ The fluctuation test of Luria and Delbruck (studying resistance to bacteriophge T1 infection) established thatA. T1 phage was a mutagen.B. Mutations could arise prior to the time they were selectedC. The mutation rate varies greatly from experiment to experiment.D. In E. coli the number of mutants per clone was relatively constant._____ E. coli cells were spread on two agar plates [one containing only agar (plate 1) and the second containing streptomycin (plate 2) which kills all cells except those that are resistant mutants]. Both plates were allowed to grow for several generations. Cells were collected from the agar plate WITHOUT streptomycin and spread again on a fresh agar plate containing streptomycin (plate 3). More mutants wereobserved on plate 3 than were observed on plate 2. The experiment demonstrates A) how to screen for environmental mutagensB) that mutation occurs in prokaryotes as well as in eukaryotesC) that in some cases mutations are caused by the selective agent itselfD) that mutations occur in the absence of the selective agentE) a direct correlation between the amount of the selective agent used and the number of resistant mutants (one-hit relationship)_____ Forty units of enzyme A are needed to produce a wild-type phenotype. The wild-type allele produces 20 units and a newmutation produces only five units. The mutation would beA. dominant B. codominantC. recessive D. conditional _____ An individual cell homozygous for a mutant allele of the gene for a human enzyme contains no detectable activity for that enzyme. The mutation is best described asA. dominant B. codominantC. prototrophic D. null_____ The rare enol form of thymine pairs with guanine. If a thymine enolization occurs during replication, what would be the mutational event?A. CG to AT B. GC to TA C. AT to TA D. TA to CG _____ A missense mutation in Neurospora will revert by treatment with nitrous acid (causes transversions), but not by hydroxylamine (causes AT -> GC transitions). The original mutation (not the reversion) must have beenA. AT to GC B. AT to TA C. AT to CG D. GC to AT_____ A wild-type chromosome can be represented as ABC * DEFGH, and from this a chromosomal aberration arises that can be represented AED * CBFGH. This is known as(* = centromere)A. Deletion B. Pericentric inversionC. Translocation D. Paracentric inversionE. Duplication_____ A female Drosophila supposedly heterozygous for two recessive mutations cn and lz that are on the same arm of the X chromosome (cn lz/+ +) surprisingly expresses both these genes. The male progeny of the female will beA. all wild type B. all cn lz C. 1/2 cn lz and 1/2 wild type D. cn + E. + lz_____ A set of Drosophila deletions was assembled as follows (the lines indicate the region that has been deleted)Regions 1 2 3 4 5 6 7 a________ b_______________ c____________ d___________ e___________ f___A radioactive DNA fragment containing a certain gene bound only to chromosomes a and f. The gene must be in the region betweenA. 1 and 2 B. 2 and 3 C. 3 and 4 D. 4 and 5 E. 5 and 6_____ An enzyme that repairs thymine dimers in visible light in E. coliA. resolvaseB. polymeraseC. photolyaseD. excision repairE. DNA glycosylase_____ An enzyme that attacks sites left after loss of a single purineA. resolvaseB. polymeraseC. photolyaseD. AP endonucleaseE. DNA