2. A chef pours a cup of rice into a pot of boiling water and observes the rice swirling around in the plot. Which of the following explains the cause of this motion? A. Heat transfer by radiation makes the rice vibrate.

B. The rice is carried along by conduction.

C. The chef stirred the pot before the rice was added.

D. The rice is carried along by convection currents.

Choose one correct answer.''

D

Explanation:

Not A > Radiation comes from the sun

Not B > Conduction involves direct contact with a heat-conducting object (if the rice were to

Not C > Irrelevant to heat transfer

oceans

indian ocean

pacific ocean

atlantic ocean

arctic ocean

southern ocean

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.