The acacia tree is protected from other insects by a certain species of ant. The ants, in turn, feed on a sweet secretion produced by the tree. This type of nutritional relationship is known as A) saprophytism

B) parasitism

C) commensalism

D) mutualism

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.

What do all macromolecules have in common with each other? oa. they all are formed from the same elements.ob. they all have major roles in cell membranesoc. they all act as catalysts in the body.od. they all have peptide bonds between carbon atoms.

Fungi are classified into how many groups? a. 1 group b. 2 groups c. 3 groups d. 4 groups