19 terms

Mastering Ch 16

In his transformation experiments, what did Griffith observe?
mixing a heat killed pathogenic strain of bacteria with a living nonpathogenic strain can convert some of the living cells into the pathogenic form
How do we describe transformation in bacteria?
assimilation of external DNA into a cell
It became apparent to Watson and Crick after completion of their model that the DNA molecule could carry a vast amount of hereditary information in which of the following?
sequence of bases
In an analysis of the nucleotide composition of DNA, which of the following will be found?
DNA replication is said to be semiconservative. What does this mean?
each new double helix consists of one old and one new strand
Replication in prokaryotes differs from replication in eukaryotes for which of the following reasons?
prokaryotic chromosomes have a singlr origin of replication, whereas euk have many
In E. coli, there is a mutation in a gene called dnaB that alters the helicase that normally acts at the origin. Which of the following would you expect as a result of this mutation?
no replication fork will be formed
Which enzyme catalyzes the elongation of a DNA strand in the 5' → 3' direction?
DNA polymerase III
What is the function of DNA polymerase III?
to add nucleotides to the 3' end of a growing DNA strand
The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that
the nucleoside triphosphates have the sugar deoxyribosome; ATP has the sugar ribose
The leading and the lagging strands differ in that
th leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.
You briefly expose bacteria undergoing DNA replication to radioactively labeled nucleotides. When you centrifuge the DNA isolated from the bacteria, the DNA separates into two classes. One class of labeled DNA includes very large molecules (thousands or even millions of nucleotides long), and the other includes short stretches of DNA (several hundred to a few thousand nucleotides in length). These two classes of DNA probably represent
leading strands of okazaki fragments
Which of the following would you expect of a eukaryote lacking telomerase?
a reduction in chromosome length in gametes
Which of the following statements describes the eukaryotic chromosome?
It consists of a single linear molecule of doubble-stranded DNA plue proteins
If a cell were unable to produce histone proteins, which of the following would be a likely effect?
The cells DNA couldnt be packed into its nucleus
Which of the following is true of DNA during interphase?
It exists an chromatin and is less condendsed than mitotic chromosomes
Which of the following is true of DNA during interphase?
It exists as chromatin and is less condensed than mitotic chromosomes
Which of the following represents the order of increasingly higher levels of organization of chromatin?
nucleosome, 30-nm chromatin
Which of the following statements describes chromatin?
Heterochromatin is highly condensed, whereas euchromatin is less compact