Following statements are given regarding to the genes in Drosophila.

A. The anterior posterior compartment of each segment of drosophila is regulated by the expression of engrailed and wingless genes.

B. The gap genes are activated or repressed by the maternal effect genes, and are expressed in one or two broad domains along the anterior-posterior axis.

C. The transcription patterns of the anterior gap genes are initiated by the different concentrations of the Hunchback and Bicoid proteins.

D. The segment polarity genes encode proteins that are constituents of the delta-notch and Hedgehog signaling pathways.

E. After the segmental boundaries are set, the pair-rule and gap genes interact to regulate the homeotic selector genes, which specify the characteristic structures of each segment.

Which one of following option has all the correct statements?

#Question id: 2864

#Unit 2. Cellular Organization

In E. coli, the five contiguoustrp genes encode enzymes that sythesize the amino acid tryptophan. These genes are expressed efficiently only when tryptophan is limiting. The genes are controlled by a repressor, just as the lac genes are, although in this case, it is the absence of its ligand (tryptophan) that relieves repression, match trp genes to their gene product,

#Question id: 2865

#Unit 2. Cellular Organization

The trp operon is controlled by repression and attenuation, providing a two-stage response to progressively more stringent tryptophan starvation. But attenuation alone can provide robust regulation: other amino acid operons such as leu and his rely entirely on attenuation for their control. Correct number of codons in leader peptide of leu & his operon  in a row;

#Question id: 2867

#Unit 2. Cellular Organization

Deletion in region 3 enhances operon or rate of transcription (in trp operon); Choose an incorrect statement.

#Question id: 2868

#Unit 2. Cellular Organization

Given the following mutants and conditions, predict the expression of the of the lacZ gene (no expression, basal level of expression, or activated level of expression). A mutant of E. coli that has a mutation in the operator of the lac operon that prevents the repressor from binding

#Question id: 2869

#Unit 2. Cellular Organization

Galactose imported into the yeast cell is converted to galactose 6-phosphate by a pathway involving six enzymes, whose genes are scattered over three chromosomes. Transcription of these genes is regulated by the combined actions of the proteins Gal4p, Gal80p, and Gal3p,

#Question id: 2870

#Unit 2. Cellular Organization

In Escherichia coli, the synthesis of tryptophan is controlled by the tryptophan operon that is repressed in the presence of excessive tryptophan. When a mutant strain that has lost the regulatory gene of the tryptophan operon is placed in a medium that contains all nutrients the cells need to grow except tryptophan, which of the following will occur?