Exam 11: DNA Replication and Recombination

List four enzymes known to be involved in the replication of DNA in bacteria.

What is the name of the replication unit in prokaryotes,and how does it differ in eukaryotes?

Which cluster of terms accurately reflects the nature of DNA replication in prokaryotes?

DNA strand replication begins with an RNA primer.

A nucleosome is a structure associated with the nuclear membrane.It helps maintain a stable relationship between the extracellular matrix and the membrane itself.

Describe the DNA base sequence arrangement at the end of the Tetrahymena chromosome and the resolution of DNA replication at the end of a linear DNA strand.

As unwinding of the helix occurs during DNA replication,tension is created ahead of the replication fork.Describe the nature of this tension and state the manner in which this tension is resolved.

Structures located at the ends of eukaryotic chromosomes are called ________.

Given that the origin of replication is fixed in E.coli,what signals the location of the origin?

The accompanying figure diagrams DNA replication as currently believed to occur in E.coli.From specific points,arrows lead to numbers.Answer the questions relating to the locations specified by the numbers. (1)Which end (5′ or 3′)of the molecule is here? (2)Which enzyme is probably functioning here to deal with supercoils in the DNA? (3)Which enzyme is probably functioning here to unwind the DNA? (4)Which nucleic acid is probably depicted here? (5)What are these short DNA fragments usually called? (6)Which enzyme probably functions here to couple these two newly synthesized fragments of DNA? (7)Is this strand the leading or lagging strand? (8)Which end (5′ or 3′)of the molecule is here?

Meselson and Stahl determined that DNA replication in E coli is semiconservative.What additive did they initially supply to the medium in order to distinguish "new" from "old" DNA?

Each of the following terms refers to the replication of chromosomes.Describe the role (relationship)of each in (to)chromosome replication. (a)Okazaki fragment (b)Lagging strand (c)Bidirectional

Which of the following terms accurately describes the replication of DNA in vivo?

An endonuclease is involved in removing bases sequentially from one end of DNA or the other.

During replication,primase adds a DNA primer to RNA.

The discontinuous aspect of replication of DNA in vivo is caused by ________.

Telomerase is an RNA-containing enzyme that adds telomeric DNA sequences onto the ends of linear chromosomes.

Describe a somewhat extraordinary finding related to the Tetrahymena telomerase enzyme.

In the Meselson and Stahl (1958)experiment,bean plants (Vicia faba)were radioactively labeled so that autoradiographs could be made of chromosomes.

Which protein is responsible for the initial step in unwinding the DNA helix during replication of the bacterial chromosome?