Which of the following contribute to maintaining the high osmolarity of the renal medulla?

I) active transport of salt from the upper region of the ascending limb

II) the spatial arrangement of juxtamedullary nephrons

III) diffusion of urea from the collecting duct

IV) diffusion of salt from the descending limb of the loop of Henle

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#Question id: 311

#SCPH01 Biochemistry

Which of the following has no contribution to the stability of tRNA?

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#Question id: 245

#SCPH12 I Genetics

Adenylate and AMP each contain ________ phosphate groups.

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#Question id: 15638

#SCPH28 | Zoology

You have isolated two mutations that show decreased expression of the Lac operon. However, unlike like the promoter mutations, these mutations don’t respond to the inducer IPTG. These mutations, designated Lac3– and Lac4–, are evaluated for the quantity of ß-galactosidase and permease activity expressed with or without IPTG:

 

Mapping experiments reveal that Lac3– and Lac4– are different short deletions located in the region before the start of the LacZ gene. Given the data shown above suggest which genetic element(s) in addition to part of the promoter has been deleted in each mutant. 

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#Question id: 2925

#SCPH01 Biochemistry

Mitotic cyclin levels in early Xenopus embryos are regulated by:

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#Question id: 3510

#SCPH01 Biochemistry

Assume that the trihybrid cross AA BB RR X aa bb rr is made in a plant species in. What proportion of F2 progeny would be expected to be homozygous for all three genes when independently assort?