Exam/Test/Quiz for Apr 7, 2010

BB Review Assessment 2 1. the non-mutated gene/protein are usually referred to as wild type. 3. DNA polymerase is not 100% error proof. 4. What is the purpose of replica plating? to identify auxotrophic mutants. 6. several enzymes need to come together to fix the damage to DNA caused by UV. Put them in order in which they need to act to repair it. endonuclease exonuclease DNA polymerase DNA ligase 7. UV can induce mutations in DNA by causing the formation of TT dimers 8. which of the following statements about mutations are true? any change in the sequence of DNA is a mutation The nature of the genetic code protects organisms against some mutations 10. the following is a DNA sequence in the right frame of reading: --AAG ATT TTG TTT TCC-- A sequence of the three nucleotides is inserted as follows: --AAG ATT TTG ccc TTT TCC the result of that mutation would be an extra amino acid in the protein. 11. When E. coli is grown in the presence of both glucose and lactose, it will first use glucose and only then start to use lactose, this is called catabolite repression. 12. the sequence of DNA in the operon where repressors bind is called an operator. 13. how does the presence of lactose turn the lac operon on disregard the positive regulation of the lac operon for this question? lactos inactivates the lac repressor. 14. An operon that is OFF by default but can be turned on in the presence of a certain chemical is called an inducible operon. 15. the tryptophan operon is an example of repressible operon. 16. how does glucose precent cells from using lactose when an e coli is grown on both the glucose and lactose at the same time? by repressingrhw aynrthesis of the lac positive regulator. 17. a group of functionally related bacterial genes that are regulated and transcribed together is called operon. 18. an operon that is on by default but can be turned off in the presence of a certain chemical is called a repressible operon. 19. Usually microorganisms do not express every sinle one of their genes at a given time. 21. Which of the following statements about double stranded DNA is(are) true. the two strands are running in opposite directions. the bases face each other 22. Nucletoides in a nucleic acid are connected because the phosphate of a nucleotide connects with a covalent bond to the sugar of the next nucleotide. 23. DNA replication usually starts at specific sequences in DNA known as the origin of replication. 24. the replication fork during the copying of DNA is made with the help of the enzyme helicase. 25. Which of the following statements about a single strand of DNA is(are) true? it has direction with phosphate at one end and OH at the other end it has a backbone of laternating sugars and phosphates. 26. match enzymes that particpate in the synthesis of the lagging strand of DNA during replication with their function. primase- starts a new fragment dna polymerase extends fragments dna ligase joins fragments together 27. what the two kinds of nucleotides in terms of their basic chemistry (number of rings)? pyrimidines purines 28. which of the following nucleotides is not found in DNA? Uracil 29. Nucleic acids are polymers made of many repeating monomers called nucleotides 30. DNA is always synthesized by adding new nucleotides to the 3' end of the growing strand. 31. What happens when an Hfr cell conjugates with an F- cell? The F- recipient cell acquires a piece of the F plasmid and a piece of the bacterial chromosome. 32. During conjugation, a plasmid is transferred from one bacterium to another via a specialized structure called the sex pilus. 33. How is the F plasmid copied? rolling circle replication 34. cells that have a copy of the F plasmid act as donors during bacterial conjugation. 36. When DNA is passed from a parent cell to its daughter cells in the process of division, we say that vertical transfer of DNA has occurred. 37. During a chromosome mapping experiment with an Hfr strain, researchers determine that gene A takes 5.7 minutes to be transferred to the recipient , while gene B takes 5.9 minutes. How are the two genes mapped on the chromosome? Gene A is closer to the F plasmid than gene B. 38. The F plasmid is transferred to the recipient cell via a specialized structure called the sex pilus. 39. in bacterial conjugation: the F plasmid is replicated and a copy is transferred to the recipient cell 40. In transduction, a viral particles trasnfer a piece of DNA from one bacterial cell to another. 42. the two main types of flow of the genetic information are transfer and expression. 43. A strong promoter will usually have a sequence that is very similar to the consensus promoter sequence. 44. the codon for the amino acid methionine which is also the start codon in bacterial proteins is AUG. 45. tRNAs have an anticodon , a three nucleotide sequence complimentary to a sequence of three nucleotides in the mRNA. 46. transcription is initiated at a specific sequence in DNA called a promoter. 47. the two processes involved in gene expression are transcription and translation. 48. a sequence of three nucleotides that codes for a specific amino acid in a protein is called a codon. 49. the chemical 5-bromouracil is a nucleoside analog. 50. nitrous acid causes mutation in DNA by chemically modifying adenine. 51. what type of mutations does nitrous acid cause? substitutions of an AT pair with a GC pair. 52. mutagenic chemicals that are structurally similar to the nitrogenous bases in nucleic acids but have slightly altered base- pairing properties are called nucleoside analogs. 53. the two kinds of viruses in terms of what surrounds the nucliec acids are naked viruses and enveloped viruses. 54. all viruses are obligatory intracellular parasites. 55. All viruses contain a single type of nucliec acid. 56. when do viruses bring their own polymerase ? when they have a nucleic acid that host cells cannot replicate. 57. Complete, fully developed, infectious virus particles are also called virion 58. in viruses, the proteins that make up the protein coat are referred to as capsomeres 59. Match the different kinds of viruses to a typical representative. Helical naked virus- tobacco mosaic virus icosahedral naked virus- polio virus enveloped virus- influenza virus complex virus- bacteriophage how do enveloped viruses send their envelope proteins to the cell membrane? they use the golgi apparatus. Which of the following are features of the influenza virus it is a segmented virus it is an enveloped virus it has two kinds of spikes