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,

Trp genes	Gene products
trpE	anthranilate synthetase
trpD	phosphoribosyl anthranilate transferase
trpC	phosphoribosyl anthranilate isomerase-indole glycerol phosphate synthetase
trpB	tryptophan synthetase beta
trpA	tryptophan synthetase alpha

#Question id: 11650

#Unit 7. System Physiology – Animal

The red lines in the figure above illustrate the normal relationships between plasma insulin concentration and glucose production in the liver and between plasma insulin concentration and glucose uptake in muscle.

In the figure, which lines most likely illustrate these relationships in a patient with acromegaly?

#Question id: 11651

#Unit 10. Ecological Principles

Succession on a newly exposed site that was not previously occupied by soil and vegetation refers to

#Question id: 11652

#Unit 10. Ecological Principles

The sequence of changes initiated by disturbance is called succession, and the ultimate association of species achieved is called

#Question id: 11653

#Unit 10. Ecological Principles

Given some characteristics of the climax community

i) Tolerate its own reactions

ii) Tends to become mesic

iii) Less stable

iv) Complex stratification

v) Simple food web

vi) Less mutualism

vii) Gross production is equals to community respiration

viii) Net community production is zero

Which of the following combination shows the characteristics of climax community?

#Question id: 11654

#Unit 10. Ecological Principles

Succession start from the water body and continuos in community dyanamics, changes species composition as well as changes in structure also. Which one is the correct composition of hydrosere process?

#Question id: 11655

#Unit 10. Ecological Principles

succession as proceeding to a distinct end point, each phase of succession shown in given diagram (A → D)