Module 4 fill in the blanks

In a survey of 240,000 human births, six achondroplastic births were recorded to parents who were unaffected. Given that this form of dwarfism is caused by a fully penetrant, dominant, autosomal gene, what is the mutation rate?

1.25x10^-5

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

10^-5 to 10^-6

_____________ are complexes where, among other activities, a great deal of RNA degradation takes place.

P bodies

Degradation of a eukaryotic mRNA is generally preceded by shortening of the _____________.

Poly(A) tail

_______________ is also known as RNA silencing and posttranscriptional gene silencing.

RNA interference

____________________act as intermediaries between ______________________________ and specific _____ sequences to modify chromatin structure and activate transcription.

Transcriptional activators,Chromatin remodeling complexes,DNA*

Apurinic (and apyrimidinic) sites (AP sites) involve a spontaneous loss of ______________ in an intact double-helix DNA molecule

a purine

Transcription factors are proteins with at least two functional _________.

binding sites

An insulator is also known as a(n) __________________

boundary element

Mutations in the lacI and lacO genes in the lactose system often lead to full production of the three structural genes related to the lac operon even with no lactose available to the organism. Such mutations would be called________.

constitutive mutations

When considering the binding of cAMP-CAP and RNA polymerase to the lac operon, both bind more efficiently than either singly. What term is applied to this increased efficiency of binding?

cooperative

What is the common influence of ultraviolet light on DNA? Note that simply stating "mutation" is not an acceptable answer.

dimer formation

Regarding the lactose utilization system in E. coli, a ___________ inducer is a molecule that is chemically analogous to lactose, induces the operon, but is not a substrate for the enzymes of the lac operon.

gratuitous

The region of a protein that is capable of holding on to a particular nucleotide sequence in order to affect proper gene regulation.

promoter

Approximately 5% of the cytosine residues are methylated in the genome of any given eukaryote. In what way is DNA methylation related to genetic regulation?

promoters and enhancers

The general term for a non-polymerase protein that binds to an operator.

repressor

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

shorter

Explain how one would use epistasis analysis to determine order of gene action in genetic networks?

A gratuitous inducer is a chemical analogue of a natural inducer. It serves as an inducer but is not a substrate for the reactions related to the natural inducer. Isopropylthiogalactoside(IPTG) is a gratuitous inducer of the lactose operon.

Strand discrimination during the process of _____________ is based on DNA methylation in E. coli.

DNA repair

Attenuation involves the termination of ______ synthesis

MRNA

Match each number with the closest type of DNA: a. moderately repetitive DNA b. highly repetitive DNA c. short interspersed elements d. long interspersed elements e. unique-sequence DNA

a. b. telomeres c. d. e. gene sequencing

Enhancers are said to be cis-acting. What is meant by cis-acting, and what are enhancers?

act on same chromosome

Describe the phenomenon of photoreactivation repair

allow bacteria to repair the thymine dimers caused by UV exposure

The _________ can be used to quickly screen chemicals for their ability to be mutagenic (and hence potentially carcinogenic).

ames test

In what way can 5'-azacytosine influence transcription?

changes pattern of gene expression

Proteins that affect chromatin structure without altering histone chemical structure are called _______________.

chromatin-remodeling complexes

The isolation of cell-cycle mutations in yeast was greatly facilitated by the use of _______________ mutations, which allow investigators to study the effects of mutations that would be lethal if expressed constantly.

conditional

Mutations in the lacI and lacO genes in the lactose system often lead to full production of the three structural genes related to the lac operon even with no lactose available to the organism. Such mutations would be called ________.

constitutive mutations

A highly-methylated region of a chromosome that has become largely deactivated and can be seen as dense-regions when viewed using electron microscopy.

heterochromatin

Constitutive mutations may occur in various components of the lac operon. Name two genes of the lac operon in which constitutive mutations could occur.

lacI- and lacOc

High-throughput technologies such as DNA and protein expression _________ are often used to provide a global picture of gene expression.

microarrays

Loss-of-function mutations that eliminate the function of a gene product are also known as _____ mutations or gene knockouts.

null mutations

What are null mutations? What classes of mutagens would most likely generate null mutations?

null mutations causee complete lack of function and no production of functional gene product. frameshift mutations

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

spontaneous

Under a system of positive control, __________ does not occur unless a regulator molecule directly stimulates RNA production.

transcription

A(n) _______________ can function at variable distances and in either orientation. However, it differs from an enhancer in that it cannot function downstream of the transcription starting point.

upstream activator