You are studying regulation of the yeast enzyme glutamine synthetase (GS), which is encoded by the GLN1 gene. You have isolated two mutants, designated gln2– and gln3–, that give decreased GS activity. Mating of either gln2– or gln3– haploids to wild type produces heterozygous diploids that show normal amounts of GS expression. When you cross either a gln2– or gln3– haploid to a gln1– strain the resulting diploids show normal expression of GS.              

 How many units of ß-galactiosidase would you expect to be expressed from deletion 4 in a gln2– mutant?

TLS Online TPP Program

#Question id: 33229

#Unit 1. Molecules and their Interaction Relevant to Biology

The effects of pH on enzymes depends on a combination of factors: 

(a) Most enzymes are active within only a narrow pH range, typically 5 to 9. 

(b) the ionization states of the amino acid residues involved in the catalytic activity of the enzyme

(c) the variation of protein structure (usually significant only at extremes of pH).

Which of the above is correct

TLS Online TPP Program

#Question id: 29510

#Unit 6. System Physiology – Plant

Which one of the following secondary metabolites is produced by  Members of the Brassicales and characterised by a sulphur-containing organic compounds derived from glucose and an amino acid?

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#Question id: 28462

#Unit 5. Developmental Biology

The two major parts of the eye (lens and retina) co-construct each other, and the eye forms from which type of interaction ?

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#Question id: 30066

#Unit 7. System Physiology – Animal

When the cholinergic vagal fibers to nodal tissue are stimulated, Membrane becomes:

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#Question id: 12329

#Unit 10. Ecological Principles

In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n)