#Question id: 11833
#Unit 6. System Physiology – Plant
Analysis of mRNA from tomato fruits from wild-type and
transgenic tomato plants genetically engineered to lack ethylene has revealed
that gene expression during ripening is regulated by at least two independent
pathways;
I) Ethylene-dependent pathway
II) Ethylene-independent pathway
Some given genes involved in these two pathways,
a) ACC oxidase
b) respiratory metabolism
c) ACC synthase
d) chlorophyllase
e) lycopene and aroma biosynthesis
Which of the following is the correct combination from the given pathways and its included genes?
#Question id: 1255
#Unit 4. Cell Communication and Cell Signaling
Following statements are regarding to the mechanism of action of cholera toxin.
A. cholera toxin is a homodimeric protein, target G proteins, interfering with normal signaling in host cells.
B. cholera toxin associates with a small G protein, known as ARF6.
C. association with ARF6 activates cholera toxin, which catalyzes the transfer of ADP-ribose from NAD+ to the critical Arg residue in the P loop of the alpha subunit of Gs.
D. ADP-ribosylation blocks the GEF activity of Gs and thereby renders Gs permanently inactive.
E. This results in continuous activation of the adenylyl cyclase of intestinal epithelial cells, chronically high cAMP, and active PKA dephosphorylates the CFTR Cl- channel and a sodium-proton exchanger in the intestinal epithelial cells.
Which of the following combination is correct?
#Question id: 19005
#Unit 13. Methods in Biology
#Question id: 11676
#Unit 7. System Physiology – Animal
In humans, the transport epithelial cells in the ascending loop of Henle:
#Question id: 4574
#Unit 11. Evolution and Behavior
Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are