Some operons have both a positive and negative control mechanism built into the DNA sequence of the operon. That means both an activator protein and a repressor protein are present simultaneously. Consider a system that has both positive and repressible negative controls. a. Describe the four combinations of active or inactive regulatory proteins that could be present at any time in the cell.

Following are the four combinations of active or inactive regulatory proteins that could be present anytime in the cell:

Active repressor , Active activator.

Active repressor, Inactive activator.

Inactive repressor, Active activator.

Inactive repressor, Inactive activator.

Explanation:

Use the attached diagram for

explanations on the four combinations of active or inactive regulatory proteins in cells.

question: which statement best describes the different properties of metals?

answer: they are shiny and bend without breaking.

since metals have certain characteristics properties, they include the following: they are ductile, malleable, shiny, hard, lustrous, flexible and they are good conductor of heat and electricity. so therefore, metals are not dull and they are not non-flexible as listed. instead, they are shiny and flexible.

hope this , have a good day. c;

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.