The blue-ringed octopus, shown below, utilizes a venom called tetrodotoxin as a defense mechanism.

tetrodotoxin binds to sodium channels and blocks the passage of sodium ions. based on this information, which symptom would most likely occur in an organism exposed to tetodotoxin?

a.
decreased appetite due to the production of hormones that indicate fullness
b.
paralysis due to lack of action potentials to signal muscle tissue
c.
increased heart rate due to increased nerve impulses to the heart muscles
d.
blindness due to proteins in the eyes denaturing and losing functionality

B.  

paralysis due to lack of action potentials to signal muscle tissue

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.