Exam 14: Gene Mutation,DNA Repair,and Transposition

What are LINES?

List five general categories of mutation.

Some bacterial transposons,known as Tn elements,are larger than insertion sequences (IS elements)and contain protein-coding genes that have human health significance.What might such a bacterial transposon contain?

Assume that a new mutation occurs in the germ line of an individual.What finding would suggest that the new mutation is dominant rather than recessive?

A mutation that occurs naturally,without exposure to a known mutagen,is called a ________.

Three major types of RNAs are mRNA,rRNA,and tRNA.For each of the conditions below,predict the consequences in terms of the population of proteins being synthesized in a particular cell.What qualitative and quantitative changes,if any,are expected in the individual protein involved (if one is involved)and in the population of proteins produced in that cell? (a)A frameshift mutation in mRNA.The condition is heterozygous in the involved cell. (b)A deletion (homozygous)that removes approximately half of the rRNA genes.

Recent discoveries on causes of fragile-X syndrome,myotonic dystrophy,and Huntington disease indicate which type of genetic alteration?

Considering the electromagnetic spectrum,identify likely mutagens from the following list: radio waves,microwaves,infrared,ultraviolet,X-rays,gamma rays,cosmic rays.

Mutations may exert a variety of effects on living systems.List at least three categories of mutations based on their biological effects.

2-amino purine is an alkylating agent.

Recombinational repair is activated when damaged DNA has escaped repair and the distortion disrupts the process of replication.Which gene is responsible for recombinational repair?

Ultraviolet light causes pyrimidine dimers to form in DNA.Some individuals are genetically incapable of repairing some dimers at "normal" rates.Such individuals are likely to suffer from ________.

All insertion sequences (IS elements)contain two features that are essential for their movement.What are these two elements?

How was it determined that X-rays are mutagenic?

Under certain conditions,the rate of mutation of a particular gene may be determined in humans.Name three properties of the mutation that would favor the most direct determination of mutation rate in humans.

Postreplication repair is a system that responds after damaged DNA has escaped repair and failed to be completely replicated.

How were insertion sequences (IS elements)first discovered?

The process of error correction of mismatched bases carried out by DNA polymerases is called ________.

Conditional mutations are more likely to result from a mutation caused by which of the following alterations to the coding region of a gene?

What is meant by the term photoreactivation repair?