BS 161 EXAM 3

BS 161 EXAM 3 1. What are chromosomes made of? DNA, RNA, and proteins DNA and proteins DNA, heterochromatin, and histone proteins DNA DNA and euchromatin - ANSWER DNA and Proteins 2. Which of the following is true of DNA during interphase? It is in the form of highly condensed chromosomes and is unavailable for gene expression. It exists as chromatin and is unavailable for gene expression. It exists as chromatin and is less condensed than mitotic chromosomes. It is in the form of highly condensed chromosomes; it is called heterochromatin. It exists as chromatin; it is completely uncoiled and loose. - ANSWER It exists as chromatin and is less condensed than mitotic chromosomes. 3. Which of the following sets of materials are required by both eukaryotes and prokaryotes for replication? double-stranded DNA, four kinds of dNTPs, primers, origins of replication topoisomerases, telomerases, polymerases G-C rich regions, polymerases, chromosome nicks nucleosome loosening, four dNTPs, four rNTPs ligase, primers, nucleases - ANSWER double-stranded DNA, four kinds of dNTPs, primers, origins of replication 4. Which of the enzymes removes the RNA nucleotides from the primer and adds equivalent DNA nucleotides to the 3' end of Okazaki fragments? I. helicase II. III. DNA polymerase III ligase IV. DNA polymerase I V. primase - ANSWER DNA polymerase I 5. RNA processing converts the RNA transcript into _____. a protein DNA a eukaryotic cell mRNA a polypeptide - ANSWER mRNA 6. The nitrogenous base adenine is found in all members of which group? proteins, triglycerides, and testosterone proteins, carbohydrates, and ATP α glucose, ATP, and DNA proteins, ATP, and DNA ATP, RNA, and DNA - ANSWER ATP, RNA, and DNA 7. Which of the following represents the order of increasingly higher levels of organization of chromatin? nucleosome, looped domain, 30-nm chromatin fiber 30-nm chromatin fiber, nucleosome, looped domain nucleosome, 30-nm chromatin fiber, looped domain looped domain, nucleosome, 30-nm chromatin fiber looped domain, 30-nm chromatin fiber, nucleosome - ANSWER nucleosome, 30-nm chromatin fiber, looped domain 8. The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following? DNA was the first genetic material. All organisms have experienced convergent evolution. Different organisms have different numbers of different types of amino acids. The same codons in different organisms translate into the different amino acids. A gene from an organism can theoretically be expressed by any other organism. - ANSWER A gene from an organism can theoretically be expressed by any other organism. 9. For any given gene, what ultimately determines which DNA strand serves as the template strand? which of the two strands of DNA carries the RNA primer the location of specific proteins (transcription factors) that bind to the DNA the location along the chromosome where the double-stranded DNA unwinds the base sequence of the gene's promoter - ANSWER the base sequence of the gene's promoter 10. Transcription begins at a promoter. What is a promoter? Part of the RNA molecule itself A site where many different proteins will bind A site found on the RNA polymerase A site in DNA that recruits the RNA Polymerase - ANSWER A site in DNA that recruits the RNA Polymerase 11. Which of the enzymes synthesizes short segments of RNA? I. helicase II. III. DNA polymerase III ligase IV. DNA polymerase I V. primase - ANSWER primase 12. Which of the following statements best describes the promoter of a protein coding gene? The promoter is a site at which only RNA polymerase will bind. The promoter is a site found on RNA polymerase. The promoter is a nontranscribed region of a gene. The promoter is part of the RNA molecule itself. - ANSWER The promoter is a nontranscribed region of a gene. 13. A part of the promoter, called the TATA box, is said to be highly conserved in evolution. Which of the following might this illustrate? The sequence is transcribed at the start of every gene. The sequence is found in many but not all promoters. Any mutation in the sequence is selected against. The sequence does not mutate. The sequence evolves very rapidly. - ANSWER Any mutation in the sequence is selected against. 14. During splicing, which molecular component of the spliceosome catalyzes the excision reaction?