Exam 15: Gene Mutation,dna Repair,and Transposition

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

List five general categories of mutation.

Although mutation is the original source of genetic variation,its influence on changing allelic frequencies is relatively minor.

Barbara McClintock discovered mobile elements in corn by analyzing the genetic behavior of two elements,Ds and Ac.The interplay between these two elements has become one of the most interesting stories of discovery in the field of genetics.How do Ds and Ac interact?

Which human condition is caused by unrepaired UV-induced lesions?

When X-rays penetrate cells,electrons are ejected from atoms of molecules.Stable molecules can be transformed into which two types of hazardous materials?

What is the common influence of ultraviolet light on DNA?

Pyrimidine dimers are typically caused by the mutagen 2-aminopurine.

What are LINES?

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.

What is meant by the term photoreactivation repair?

Two formal terms used to describe categories of mutational nucleotide substitutions in DNA are ________.

The shorter the wavelength of a radiation source,the greater its likelihood of causing damage.

IS (insertion sequences)elements are stable DNA occupants of prokaryotic genomes that are not found among eukaryotes.

How was it determined that X-rays are mutagenic?

A 2-aminopurine is an alkylating agent.

Certain base analogs such as 5-bromouracil cause mutations by chemically altering nitrogenous bases in nonreplicating DNA.

In general,mutation rates in humans occur in the range of ________ (frequency)per gamete per generation.

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

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