The symbols , -, and 0 are to be used to show the results of interactions between individuals and groups of individuals. The symbol denotes a positive interaction, - denotes a negative interaction, and 0 denotes where individuals are not affected by interacting. The first symbol refers to the first organism mentioned. What interactions exist between cellulose-digesting organisms in the gut of a termite and the termite?

A) +/+

B) +/-

C) 0/0

D) -/-

A) +/+

Explanation:

The form of interaction that exist between cellulose-digesting organisms in the gut of a termite and the termite itself is a +/+ interaction.

This is because the interaction of both organisms is beneficial to each of them. While the cellulose-digesting organisms are able to get their shelter in the gut of the termite, the termite benefits from the presence of these cellulose-digesting organisms by getting their cellulose-containing food materials digested by them.

Hence, it is a mutually beneficial interaction.

Option A is the correct option.

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.