David and his lab partner are dissecting an earthworm during biology lab. they are cutting the earthworm with a scalpel in order to examine the inside of the worm. which of the following safety procedures should they follow while using the scalpel? a. always cut away from yourself and others. b. do not wear gloves to protect your hands. c. do not clean the scalpel after the dissection is done. d. always hold the organism in your hands while cutting.

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.