The gills of fish maintain effective oxygen uptake from water and the legs of seagulls reduce the loss of heat to the external environment by the same circulatory mechanism known as __________.

#Question id: 1003

#Unit 1. Molecules and their Interaction Relevant to Biology

The glucose-alanine cycle provides ________.

#Question id: 11951

#Unit 7. System Physiology – Animal

Very early in embryonic development, testosterone is formed within the male embryo. What is the function of this hormone at this stage of development?

#Question id: 132

#Unit 1. Molecules and their Interaction Relevant to Biology

Proline is distinct among the 20 commonly found amino acids because

#Question id: 2953

#Unit 2. Cellular Organization

If a cell in the G1 phase is fused with a cell in the S phase, then

#Question id: 2855

#Unit 2. Cellular Organization

Which statements are correct about lac operator;

I. The site bound by the Lac repressor.

II. The lac operator overlaps the promoter, and so the repressor bound to the operator physically prevents RNA polymerase from binding to the promoter and thus inhibit the RNA synthesis.

III. Have 21-bp sequence with twofold symmetric and is recognized by four subunits of Lac repressor, two binding to each half-site.

IV. CAP binds as a dimer to a site similar in length to that of the lac operator, but different in sequence. This site is located some 60 bp upstream of the start site of transcription.