The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. In chemical digestion, enzymes break down food into the small molecules the body can use.igestion begins in the mouth with the secretion of saliva and its digestive enzymes. Food is formed into a bolus by the mechanical mastication and swallowed into the esophagus from where it enters the stomach through the action of peristalsis.
The stigma is generally in the center of the flower and stands up on the style, taller than the surrounding anthers. It usually has a gelatinous or visceral appearance, which is slightly damp and furry.
The stigma is the stem. Reply:pollen, but it is only found in male flowers. Reply:Sounds to me as though you are talking about the central yellow part of a daisy flowering head (although these are not always yellow either). If you are, it is called the disk and is covered with small flowers called florets.Otherwise, the center part of a flower isn't always yellow, unless it has a large yellow stigma (the top part of the gynoecium, aka pistil).he stigma is the stem. Reply:pollen, but it is only found in male flowers. Reply:Sounds to me as though you are talking about the central yellow part of a daisy flowering head (although these are not always yellow either). If you are, it is called the disk and is covered with small flowers called florets.