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

44.A silver bar is the ________ for a first lieutenant in the Army. (A)insignia (B)ensign (C)opportunity (D)interest

45.Some teenagers prefer ________ their friends to calling them on their cell phones. (A)reading (B)texting (C)checking (D)talking

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

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

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

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.