Following statement regarding to the cascade of regulated RNA splicing controls drosophila sexual differentiation.

A. The Sex-lethal (Sxl) protein, encoded by the sex-lethal gene, is the first protein to act in the cascade and present only in female embryos.

B. Early in development, the Sxl gene is transcribed from a promoter that functions only in male embryos.

C. Later in development, this male-specific promoter is shut off, and another promoter for sex-lethal becomes active in both male and female embryos.

D. In male embryos, however, in the absence of early Sxl protein, exon 3 of the sex-lethal pre-mRNA is spliced to exon 2 to produce an mRNA that contains a stop codon early in the sequence.

Which of the following is correct?

#Question id: 9152

#Unit 9. Diversity of Life Forms

In mountainous areas of western North America, north-facing slopes would be expected to ________.

#Question id: 889

#Unit 1. Molecules and their Interaction Relevant to Biology

The cis and trans GroEL rings undergo conformational changes in a reciprocating fashion, with events in one ring influencing events in the other ring. The entire GroEL/ES chaperonin complex functions as follows;

a) One GroEL ring that has bound 7 ATP also binds an improperly folded substrate protein, which associates with hydrophobic patches that line the inner wall of the GroEL chamber

b) The GroES cap then binds to the GroEL ring like a lid on a pot, inducing a conformational change in the resulting cis ring

c) Within ~10 s the cis ring catalyzes the hydrolysis of its 7 bound ATPs and releases the resulting Pi , which weakens the interactions binding GroES to GroEL

d) A second molecule of improperly folded substrate protein binds to the cis ring, followed by 7 ATP

e) The binding of substrate protein and ATP to the cis ring conformationally induces the trans ring to release its bound GroES, 7 ADP, and the presumably now better-folded substrate protein

Which of the following is incorrect functions of GroEL/ES chaperonin complex?

#Question id: 3021

#Unit 2. Cellular Organization

The lag phase of the bacterial growth curve is marked by

#Question id: 11123

#Unit 9. Diversity of Life Forms

Cladograms (a type of phylogenetic tree) constructed from evidence from molecular systematics are based on similarities in

#Question id: 11047

#Unit 6. System Physiology – Plant

As plants absorb water from the soil, they deplete the soil of water near the surface of the roots, This depletion due to