The abdominopelvic is composed of the abdominal cavity and the pelvic cavity. This cavity contains the organs such as liver, stomach, spleen, gallbladder, pancreas, kidney and most of the intestines along with the internal reproductive organs and urinary tract. The navel is located in the umbilical region of the abdominopelvic cavity.
Hence, the blank can be filled with 'umbilical region'.
Operons afford the organism the opportunity to
simultaneously regulate transcription of multiple genes, whose products are
active in the same process. Operons lead to the synthesis of groups of functionally
related enzymes, usually from a single mRNA transcript hence makes regulation of
the genes highly efficient.
C is found in cell membranes
Animals because that is not part of a cell house