Ap Classroom Ch.14

If a segment of DNA is 5'-TAC GAT TAG-3', the RNA that results from the transcription of this segment will be

3'-AUG CUA AUC-5'

Which of the following messenger RNA sequences could code for both of the two amino acid sequences above, simply by a shift in the reading frame?

AGCAGCAGCAGC

. . . . glycine-serine-glycine . . . Which of the following DNA strands will code for the amino acid sequence shown above?

CCTTCGCCT

This group of questions refers to the following enzymes. (A) DNA ligase (B) DNA polymerase (C) RNA polymerase (D) Restriction enzyme (E) Reverse transcriptase Enzyme used during replication to attach Okazaki fragments to each other

DNA ligase

This group of questions refers to the following enzymes. (A) DNA ligase (B) DNA polymerase (C) RNA polymerase (D) Restriction enzyme (E) Reverse transcriptase Enzyme used to position nucleotides during DNA replication

DNA polymerase

Figure 1. Model including molecules involved in DNA replication Which of the following correctly explains where DNA replication will begin on the strand oriented 5'→3', reading from left to right?

DNA replication will be initiated immediately to the left of the RNA since DNA polymerase requires an RNA

Item 3 A model that represents a process occurring in a cell of a particular organism is shown in Figure 1. The figure presents a diagram of a segment of double stranded D N A helix where the two strands in the middle portion of the helix have separated from each other. Twelve bases are indicated on each of the two strands. Seven complementary bases, with the sequence A U G A U C U, are shown bound to the bottom of the two DNA strands, starting from the left end of the strand. An arrow above the seven bases points from left to right. Figure 1. Process occurring in a cell Which of the following correctly explains the process shown in Figure 1 ?

Initiation of transcription is occurring because a strand of RNA RNA is being produced from a DNA DNA template strand.

Figure 1. Model of a process involving nucleic acids Which of the following best explains what process is represented in Figure 1 ?

New DNA strands are being synthesized in the 5' to 3' direction from their DNA templates.

Step 1, D N A to, step 2, Pre m R N A to, m R N A to, step 3, protein. Which of the following best describes an event during step 2 in the simplified model above?

Noncoding sequences are removed from a newly synthesized RNA molecule.

Which of the following statements best explains the structure and importance of plasmids to prokaryotes?

Plasmids are circular, double-stranded DNA. DNA molecules that provide genes that may aid in survival of the prokaryotic cell.

Enzyme used in the synthesis of mRNA

RNA polymerase

Erwin Chargaff investigated the nucleotide composition of DNA. He analyzed DNA from various organisms and measured the relative amounts of adenine (A), guanine (G), cytosine (C), and thymine (T) present in the DNA of each organism. Table 1 contains a selected data set of his results. Which of the following statements best explains the data set?

Since the %A and the % T are approximately the same in each sample, adenine and thymine molecules must pair up in a double-stranded DNA molecule .

Figure 1 represents part of a process that occurs in eukaryotic cells. There are untranslated regions (UTR) in this sequence. The figure presents a diagram representing a cellular process. At the top of the diagram is a line marked out into 7 segments. From left to right, the segments are labeled: 5 prime U T R, Exon 1, Intron 1, Exon 2, Intron 2, Exon 3, 3 prime U T R. Three arrows extend down from this top line. One arrow extends from Intron 1 in the top line to a line segment the size of intron 1 that is labeled as Intron 1. A second arrow extends from Intron 2 in the top line to a line segment the size of intron 2 that is labeled Intron 2. A third arrow extends from the top line to a line at the bottom of the diagram. The far left end of the bottom line has the label 5 prime cap followed by a small circle. Following this the line is then marked out into 6 segments that are labeled from left to right: 5 prime U T R, Exon 1, Exon 2, Exon 3, 3 prime U T R, Poly A Tail. Figure 1. Cellular process involving nucleic acids Which of the following best explains the process represented by Figure 1 ?

The enzyme-regulated processing of pre‑ mRNA mRNA into mature mRNA mRNA

The features of this model provide evidence for which explanation of why all growing strands are synthesized in a 5′ to 3′ direction?

The phosphate group, attached to the 5′ carbon of the dTMP forms a covalent bond with the oxygen atom attached to the 3′ carbon of the growing strand.

Which of the following normally leads to the production of functional messenger RNA in eukaryotic cells?

The removal of portions of RNA known as intervening sequences (introns)

Which of the following statements concerning a gene is correct?

a gene can code for a specific protein

Cells that contain only circular chromosomes are most probably which of the following?

bacterial cells

Which of the following statements best explains how the genes for antibiotic resistance can be transmitted between bacteria without the exchange of bacterial chromosomal DNA?

the genes for antibiotic resistance are located on a plasmid that can be passed to neighboring bacteria.

Process in which RNA is produced by using a DNA template

transcription

Item 9 Figure 1 represents part of a process essential to gene expression. The figure presents a diagram with a double helix of D N A. Figure 1. Model of process involved in gene expression. Which of the following best explains what strand X represents?

The antisense strand, because it is serving as a template