1. Match each term with the correct definition. a. Abdomen b. Chest c. Genitals d. Pelvis e. Sternum External reproductive organs The middle part of the trunk, containing the stomach, liver and spleen The upper part of the trunk, containing the heart, major blood vessels and lungs Long, flat bone in the middle of the front of the rib cage, also called the breastbone The lower part of the trunk, containing the intestines, bladder and reproductive org

A. Abdomen:- The middle part of the trunk, containing the stomach, liver and spleen.

B. Chest:- The upper part of the trunk, containing the heart, major blood vessels and lungs.

C. Genitals:- External reproductive organs .

D. Pelvis:- The lower part of the trunk, containing the intestines, bladder and reproductive org.

E. Sternum:- Long, flat bone in the middle of the front of the rib cage, also called the breastbone.

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.