Exam 5: Dna Structure, Replication, and Recombination

What observation supports the hypothesis that recombination occurs after replication? How would outcome differ if recombination preceded replication?

Design an experiment to demonstrate that recombination involved breakage and rejoining of DNA molecules.E.coli with phage grown in either heavy or light isotopes,and then after allowing for recombination (but not replication),separated the DNA by centrifugation in a CsCl density gradient.The recombinant molecules,consisting of various combinations of heavy or light molecules,would migrate to positions in between the non-recombinant molecules,which consisted entirely of either heavy or light DNA.

The process of _________ is extremely important in generating genetic diversity.

Without __________ regions on the DNA during recombination,gene conversion could not occur.

Which of these would compensate for a lack of telomerase?

While duplicating an entire chromosome,DNA polymerase cannot begin the 5' end of a new strand without a primer.

Any deviation from the expected 2:2 segregation of parental alleles that results from recombination is known as

Histones appear to have a singular role in the packaging of DNA.The nonhistone proteins in chromatin have all of the following functions except

Which of the following is not usually seen when a cell loses telomerase activity?

With regard to the typical human cell,which of the following appears to be true?

Which of the following are properties of telomeres?

During mitosis,kinetochores develop during

If removal of a DNA sequence disrupts chromosome segregation and reinsertion of the same sequence restores stable transmission,the sequence must lie within the centromere.

Ignoring the detailed description of how DNA polymerase functions,discuss the roles that proteins play in reproducing chromatin structure.

Yeast research with autonomously replicating sequences (ARSs),along with digestion of chromatin with DNase I,have led scientists to determine that

It appears that all origins of replication are active during all mitotic divisions that create an organism.

The chromosome can be considered a dynamic organelle for _______________ of DNA.

In yeast chromosomes,centromeres

Which of the following enzymes is not required for recombination in the double-strand break repair model?

Scaffold-associated regions (SARs)likely serve to attach chromatin loops to the condensation scaffold.