What caused this sandbar to form? A. wind
B. gravity
C. waves
D. erosion

I'm asking this for one of my siblings please help!

The trp operon in e.coli regulates genes that code for enzymes required for synthesis of the repressible operon. when tryptophan is not available amino acid tryptophan. the trp operon is a in the environment, the trp repressor protein activeinactiveregulated. therefore, rna polymerase can bind to the genes to begin transcription.

_tissues respond quickly to outside stimuli a) epithelia b)nervous c)muscular d)muscular and nervous

What is the function of the root cap? a. extra-absorbent cells in the root cap absorb more water and nutrients b. protect the meristematic area of the stem c. contains sensors for sunlight d. increases surface area of the root