Transposition by a bacterial insertion element

a. occurs at a frequency of approximately 1 in 10^3 cells per generation.

b. can inactivate an essential gene.    

c. is mediated through a RNA intermediate.

d. requires the enzyme transposase

#Question id: 1219

#Unit 4. Cell Communication and Cell Signaling

Many G protein-coupled receptors contain seven transmembrane α-helical domains. The amino end of the protein lies at the exterior of the plasma membrane. Loops of amino acids connect the helices either at the exterior surface or on the cytosolic surface of the membrane. The loop on the cytosolic side between helices 5 and 6 is usually substantially longer than the others. Where would you expect to find the carboxyl end of the protein?

#Question id: 4733

#Unit 8. Inheritance Biology

If a homozygous plant with red peppers is crossed with a homozygous plant with green peppers, all the F1 plants have red peppers. When the F1 are crossed with one another, the F2 are in a ratio of 9 red : 3 brown : 3 yellow : 1 green  due to

#Question id: 2675

#Unit 2. Cellular Organization

Which of the following statements regarding the trp operon is true?

#Question id: 14518

#Unit 13. Methods in Biology

#Question id: 6632

#General Aptitude

If + = ÷ , ÷ = - , - = × , × = + , then 12 + 6 ÷ 3 – 2 × 8