50. I didn't know how to use that weapon until I got some________.
(A)job
(B)duty
(C) chance
(D) training

46.If you want to get a job here in this bank, you need to go the________office. (A)personnel (B)opportunity (C)promotion (D)duty

47.Rex: Did you see the general when you went to Washington? Roy: No, I didn't have the________ to see him. (A)training(B)opportunity(C)promotion(D)location

48. If you're a father, it's your ________ to spend time with your family. (A)assignment (B)chance (C)duty(D)training

49. Pete: What are you going to do after your ________? Henry: I'm just going to take it easy. (A)retirement (B)opportunity(C)commander(D)major

1. A cell or organism that possesses two homologous copies of each of its chromosomes is described as: (A) Haploid (B) Triploid (C) Diploid (D) Aneuploid(E) Polyploid

2. What type of bond links nucleotides together to form a strand of DNA or RNA? (A) Hydrogen bond (B) Phosphodiester bond (C) Peptide bond (D) Glycosidic bond (E) Ionic bond

3. Which of the following best describes the function of histones ineukaryotes?(A) To negatively supercoil DNA.(B) To act as enzymes that cut and paste DNA.(C) To serve as a scaffold for RNA synthesis.(D) To package and organize DNA into nucleosomes.(E) To provide structural support to the cell membrane.

4.What is the key difference between exonucleases and endonucleases?(A) Exonucleases remove nucleotides from the middle of a DNA strand, whileendonucleases remove nucleotides from the ends of DNA strands.(B) Exonucleases are found in eukaryotes, while endonucleases are found inprokaryotes.(C) Exonucleases are used in DNA replication, while endonucleases are used inDNA repair.(D) Exonucleases remove nucleotides from the ends of a DNA strand, whileendonucleases remove nucleotides from within a DNA strand.(E) Exonucleases only act on single-stranded DNA, while endonucleases onlyact on double-stranded DNA.

5.A researcher is using degenerate primers to amplify a gene from a newly discovered organism. They designed the primers based on a short peptide sequence from a protein that they think is encoded by the gene. What is the most likely reason that a pool of different primers is needed for PCR amplification in this scenario? (A) The use of degenerate primers ensures that the PCR reaction has multiple binding sites on the DNA template, thus amplifying the sequence more efficiently. (B) The use of degenerate primers ensures the amplification of multiple related. genes. (C) Many amino acids are encoded by multiple codons, so there are several. possible DNA sequences that could code for the same peptide sequence. (D) Degenerate primers help overcome the mispriming that can occur during PCR. (E) Degenerate primers increase the specificity of the PCR reaction.

6.What is the main advantage of using cDNA rather than genomic DNA whencreating an expression library for eukaryotic genes?(A) cDNA is easier to isolate and purify than genomic DNA.(B) cDNA is more stable than genomic DNA.(C) cDNA contains promoter sequences that are needed for expression.(D) cDNA lacks introns, which allows for proper expression in a bacterial host.(E) cDNA is double-stranded, while genomic DNA is single-stranded.