Brock Biology of Microorganisms Chapter 4 Exam Questions With Correct Answers

Brock Biology of Microorganisms Chapter 4 Exam Questions With Correct Answers The functional unit of genetic information is the A) nucleotide. B) gene. C) chromosome. D) protein. - answerB) gene Which of the following statements is TRUE concerning mRNA? A) mRNA has a very short half-life. B) mRNA has complex secondary structure. C) mRNA is catalytic. D) mRNA is the product of translation. - answerA) mRNA has a very short half-life. DNA-binding proteins interact predominantly within which portion of a double-stranded DNA helix? A) major groove B) minor groove C) 3' end D) supercoil - answerA) major groove AT-rich DNA will denature/melt A) at a higher temperature than GC-rich DNA. B) at a lower temperature than GC-rich DNA. ©SIRJOEL EXAM SOLUTIONS 10/3/2024 9:54 PM C) usually at the same temperature as GC-rich DNA, with some minor variations. D) in accordance with the animal or plant from which it was taken. - answerB) at a lower temperature than GC-rich DNA Supercoiling is important for DNA structure, because A) it holds together the antiparallel strands of DNA in the double helix. B) it provides energy for transcription. C) it condenses the DNA so that it can fit inside the cell. D) it prevents RNA from pairing with DNA in the double helix. - answerC) it condenses the DNA so that it can fit inside the cell Many pharmaceutical drugs specifically inhibit transcription in Bacteria but not Archaea or Eukarya. Why would drugs that inhibit transcription only affect Bacteria and not Archaea even though they are both prokaryotes? A) Archaea and Eukarya have very similar ribosomes that are different than bacterial ribosomes. B) Bacteria lack a nucleus. C) Archaea lack operons. D) Archaea and Eukarya have very similar RNA polymerases that are different than bacterial RNA polymerases. - answerD) Archaea and Eukarya have very similar RNA polymerases that are different than bacterial RNA polymerases. How are plasmids different than chromosomes? A) Plasmids are always small, linear pieces of DNA. B) Plasmids are composed of single-stranded DNA. C) Plasmids contain genes that are NOT essential for cellular growth and replication. D) Plasmids carry unimportant genes that are of little significance for the ecology and metabolism of an organism. - answerC) Plasmids contain genes that are NOT essential for cellular growth and replication. Genes that encoded for polymerases, gyrases, ribosomal proteins, and other proteins essential to replication, transcription, and translation are present on A) chromosomes. B) plasmids. ©SIRJOEL EXAM SOLUTIONS 10/3/2024 9:54 PM C) chromosomes and plasmids. D) neither chromosomes nor plasmids. - answerA) chromosomes. The precursor of each new nucleotide in a strand of DNA is a A) deoxynucleoside 5'-diphosphate. B) deoxynucleoside 3'-diphosphate. C) deoxynucleoside 5'-triphosphate. D) deoxynucleoside 3'-triphosphate - answerC) deoxynucleoside 5'-triphosphate. DNA replication always proceeds in only one direction because the ________ of the incoming nucleotide is attached to the free ________ of the growing DNA strand. A) 5'-phosphate / 3'-hydroxyl B) 3'-phosphate / 5'-hydroxyl C) 5'-deoxyribose / 3'-base D) 3'-base / 5'-deoxyribose - answerA) 5'-phosphate / 3'-hydroxyl 11) Which of the following is formed on the lagging strand during DNA synthesis? A) DNA secondary structures B) Okazaki fragments C) RNA polymerase D) replisomes - answerB) Okazaki fragments The template for RNA polymerase is ________, and the new RNA chain is ________ to the template. A) an independent RNA segment / parallel and identical B) DNA / antiparallel and complementary C) an independent RNA segment / antiparallel and complementary D) DNA / parallel and identical - answerB) DNA / antiparallel and complementary In the process of transcription, promoters are specific sequences of ________ that are recognized by ________. A) DNA / DNA polymerase ©