In individuals heterozygous for a chromosome inversion, the homologous chromosomes form a loop in prophase I of meiosis.

Which of the following is effect of inversion?

A. A dicentric and an acentric chromosome in meiosis I as the chiasmata gets terminated when inversion includes centromere  

B. Appearance of deletion and duplication in both the cross over products chromosomes when centromere outside of inversion region  

C. All recombinant gamete are non-viable gametes when single crossing over within inverted region; irrespective to paracentric or pericentic inversion

D. Nonviable gametes are usually produced, resulting in a depression in observed recombination frequencies.

Which of the above statements are correct?

#Question id: 4485

#Unit 3. Fundamental Processes

In multicellular organisms, regulatory sequences can spread thousands of nucleotides from the promoter—both upstream and downstream—and can be made up of tens of regulator binding sites. Often, these binding sites are grouped in units called_?

#Question id: 4486

#Unit 3. Fundamental Processes

Activators can recruit factors needed for polymerase to initiate or elongate transcription. In all of these functions, the activator is merely recruiting proteins to the promoter. In bacteria, RNA polymerase is the only protein that needs to be recruited; this is not the case in eukaryotes. Indeed, in eukaryotes, a given activator might work in all three ways:

#Question id: 4487

#Unit 3. Fundamental Processes

Choose correct statements about nucleosome modifiers

#Question id: 4488

#Unit 3. Fundamental Processes

One component of thecomplex bears bromodomains and thus binds to acetylated nucleosomes better than to unacetylated nucleosomes. Thus, a gene bearing acetylated nucleosomes at its promoter will likely have a higher affinity for the transcriptional machinery than one with unacetylated nucleosomes.

#Question id: 4489

#Unit 3. Fundamental Processes

HSP70 gene from Drosophila. This gene, activated by heat shock, is controlled by two activators GAGA binding factor and HSF,In response to heat shock, HSF binds to specific sites at the promoter and recruits a kinase, P-TEFb (positive transcription elongation factor). What is the proper mechanism of pausing and release of Pol II ?

#Question id: 4490

#Unit 3. Fundamental Processes

The human immunodeficiency virus (HIV), which causes AIDS, transcribes its genes from a promoter controlled by P-TEFb (and SEC). Again, polymerase initiates transcription at that promoter, under the control of which activator?