Nucleic acids are very small, simple molecules. structural molecules that do not have a function other than support. composed of building blocks called nucleotides. sources of cellular energy. all of the above.

composed of building blocks called nucleotides.

Nucleic acids are small but not simple molecules. They are the most important biomolecules because of their several functions. They are composed of building blocks called nucleotides but not a source of cellular energy. 

the abdomen (less formally called the belly, stomach, tummy or midriff) constitutes the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. the region occupied by the abdomen is termed the abdominal cavity. the stomach secretes acid and enzymes that digest food. ridges of muscle tissue called rugae line the stomach. the stomach muscles contract periodically, churning food to enhance digestion. the pyloric sphincter is a muscular valve that opens to allow food to pass from the stomach to the small intestine.

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain