Define and give an example of position effect variegation

What will be an ideal response?


Ans: Position effect variegation (PEV) occurs when genetically identical cells are phenotypically different as a result of gene inactivation. This inactivation may be a result of local heterochromatin formation found in some cells but not in others. One example occurs in Drosophila fruit flies, when the wild-type white allele (expressed in the eye) in inactive in some cells and active in others, resulting in patches of red cells (wild-type allele is expressed) and white cells (wild-type allele is inactive).

Biology & Microbiology

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A wind system that influences large climatic regions and reverses direction seasonally, producing dry and wet seasons, is referred to as a(n):

a. geothermal ecosystem b. upwelling c. taiga d. monsoon e. hurricane

Biology & Microbiology

When using a reporter gene to investigate expression of a target protein, the promoter of the ________ is ligated to the coding sequence of the ________

a. green fluorescent protein / lacZ b. lacZ / green fluorescent protein c. reporter gene / target gene d. target gene / reporter gene

Biology & Microbiology

What is the function of the MutS protein in methyl-directed mismatch repair?

A. To excise the mismatched basepair. B. To find mismatches. C. To directly bind the DNA polymerase. D. To make a cut in the nonmethylated DNA strand. E. To digest the nonmethylated DNA strand.

Biology & Microbiology

Of the following fermentation pathways, which can be carried out by human muscle cells?

A) alcoholic B) butanediol C) lactic acid: homolactic D) lactic acid: heterolactic E) mixed acid

Biology & Microbiology