K.C.S.E Biology Q & A - MODEL 1998PP1QN20
Explain how the mammalian intestines are adapted to perform their function.
The mammalian intestines are relatively long/coiled/folded. This allows food enough (enough) lime/increases surface area for digestion and absorption of products of digestion. The intestinal surface area for absorption. The glands have enzymes which secrete enzymes for digesting e.g. of correct enzyme, maltase, sucrase, lactase, enterokinase and peptidases. Some glands/goblets cells also produce mucus which protects the intestinal wall from being digested, reduce friction. Intestines have opening of ducts which allows bile/pancreatic juice into the lumen. The intestines have circular and longitudinal muscles whose contraction/relaxation/peristalis leads to the mixing of food with acc. At least enzymes/juices facilitating rapid digestion and helps pus food along the gut. Intestines are well supplied with blood vessels to supply oxygen/remove digested food. Presence of lacteal vessels for transport of fats/lipids.
Have thin epithelia to facilitate fast/rapid absorption/diffusion. Allow increase in surface area for absorption only.
Cell biology/cytology. Occurrence of cell e.g. mitochondria, ribosome’s, nucleas, cytochromes organelle point to a common ancestry.