Genetics practice exam 2|42 Questions with Verified Answers
. Which enzyme untwists the parent strands of DNA during replication? - CORRECT ANSWER DNA
... [Show More] helicase
Tetrad analysis is a technique for - CORRECT ANSWER Mapping genes in organisms retaining the four meiotic products in one structure
The enzymes most directly concerned with catalyzing DNA synthesis is - CORRECT ANSWER DNA polymerase
What did Lederberg and Tatum's 1946-experiment show? - CORRECT ANSWER That sexual recombination can occur between bacterial cells
DNA and RNA are polymers of - CORRECT ANSWER nucleotides
During transcription, the RNA polymerase moving on the template strand in which direction? - CORRECT ANSWER . 3' to 5' only
Nucleosomes typically consist of which of the following? I. DNA; II. Histones; III. Microtubules - CORRECT ANSWER d. I and II Only
A StrS mutant: - CORRECT ANSWER cannot grow in the presence of streptomycin
Phage that can grow using either a lytic or lysogenic pathway are called - CORRECT ANSWER temperate
Analysis of bases of a nucleic acid sample yielded the following result: A, 31%; G, 14%; C, 19%; T, 36%. The sample is most likely - CORRECT ANSWER Single - stranded DNA
An example of a heritable disease that results from a biochemical defect in a nonenzymatic protein is, - CORRECT ANSWER Sickle cell anemia
The majority of naturally occurring DNA form in humans is - CORRECT ANSWER B form
Which enzyme is responsible for new strand elongation during DNA replication in E. coli? - CORRECT ANSWER DNA polymerase 3
. In yeast, the cross ab X ++ produces a tetrad having only two types of spores a+, and +b. How would you classify this tetrad? - CORRECT ANSWER non-parental ditype
The RNAs that are used in eukaryotic translation include all of the following except - CORRECT ANSWER siRNA
The -10 and the -35 boxes found in bacterial gene promoters function to: - CORRECT ANSWER orient RNA polymerase at a gene's transcription start site.
. In mapping a high blood pressure gene in humans, the LOD score is 3.9 for the marker A on chromosome X. Which of the following is most likely true? - CORRECT ANSWER The high blood pressure gene is likely linked with the marker A
The chromosome of most prokaryotes differs from those of eukaryotes because - CORRECT ANSWER the prokaryotic chromosome is circular, while the eukaryotic is linear
Loosely aggregated DNA bound to proteins in a eukaryotic cell is called_________; when the cell divides, this condenses into ___________. - CORRECT ANSWER chromatin, chromosomes
Which of the following processes does not directly involved DNA? - CORRECT ANSWER translation
Null mutants for the enzyme E3 gene will grow on minimal medium supplemented with compounds: - CORRECT ANSWER Y or Z only
The aminoacyl-tRNAsynthetase enzymes are responsible for: - CORRECT ANSWER adding amino acids to appropriate tRNAs.
In what cellular compartment are introns removed from pre-mRNA to make mature mRNA? - CORRECT ANSWER nucleus
markers a and c are co-transduced at a frequency of 17%; - markers a and b are co-transduced at a frequency of 8%; - markers c and b are co-transduced at a frequency of 2% - CORRECT ANSWER The order is b-a-c, and a is closer to c than to b
Which of the following enzymes is responsible for transcription of the CFTR gene in your body? - CORRECT ANSWER RNA polymerase 2
Which of the following is not a major enzyme during DNA replication? - CORRECT ANSWER RNA polymerase 2
Which of the following is not true about telomerase in humans? - CORRECT ANSWER Telomerase is usually highly expressed in somatic cells
The nucleic acid of Ebola virus consists of - CORRECT ANSWER single-stranded RNA
In the HGP research, various vectors were used to generate libraries to include the whole home genome. Which of the vector usually contains the smallest insert? - CORRECT ANSWER plasmid
Which of the following is the largest category of transposable elements in humans? - CORRECT ANSWER LINEs
Which of the following is not true about the Ac/Ds system in determining kernel colors in maize? - CORRECT ANSWER Colorless kernels are due to the Ac gene jumping into the C gene
Genetic mutations can be caused by errors during DNA replication. Which of the following pairings usually does not occur? - CORRECT ANSWER Normal guanine: Rare imino form of adenine (G:A*)
In 1970s, Leland Hartwell did a genetic screening in yeast and eventually led him to win a Nobel Prize in 2001. What is the significance of his experiment? - CORRECT ANSWER He identified some lethal mutations that was involved in cell division in yeast by using a conditional mutagenesis.
Two genes A and B is about 10 cM on the human chromosome 3. Which would be the closest estimated for the distance between A and B? - CORRECT ANSWER Approximately 10 Mb
The first exon of a gene has the template DNA sequence 5'-GTA-3'. What mRNA sequence would be transcribed corresponding to the template DNA sequence 5'-GTA-3', what tRNA anticodon would recognize it? - CORRECT ANSWER 5'- UAC -3 (mRNA), 5'- GUA -3' (tRNA anticodon)
We have discussed the molecular mechanism of genetic recombination in class. Which of the following is not true? - CORRECT ANSWER There would be a crossing-over if the resolutions of both Holiday intermediates are horizontal.
Thymine dimer caused by UV light can be repaired by which of the following? - CORRECT ANSWER The excision repair system
Based on the Wobble hypothesis, which of the following statements is true? - CORRECT ANSWER The nucleotide at 5' end of an anticodon of tRNA is a Wobble position.
. A strain of E. coli has the genotype (and phenotype) leu- lac- . This notation means that this strain of bacteria is unable to: - CORRECT ANSWER synthesize the amino acid leucine and utilize the sugar lactose.
Which of the following rRNAs is a part of the small ribosomal subunit in eukaryotes? - CORRECT ANSWER 18S rRNA
If a gene exon has the following sequence of noncoding strand: 5'- GACGTA-3', what is the mRNA transcript sequence after transcription: - CORRECT ANSWER 5'- UACGUC-3'
An E. coli colony grew on minimal medium supplemented with glycine and phenylalanine. However, bacteria from this colony are unable to grow and form colonies on minimal medium supplemented with glycine and serine. What is the genotype of the bacteria in this E. coli colony? - CORRECT ANSWER gly+ phe- ser+ [Show Less]