It is the part of the digestive tract where approx 90% of the digestion and absorption of food occurs, the other 10% taking place in the stomach and large intestine. The main function of the small intestine is absorption of nutrients and minerals.That is, absorption of the nutrients and minerals in the food ingested, usually via the mouth, at an earlier stage in the digestive process.t is the part of the digestive tract where approx 90% of the digestion and absorption of food occurs, the other 10% taking place in the stomach and large intestine. The main function of the small intestine is absorption of nutrients and minerals.
Green seaweeds. Characteristics: Green colour from chlorophyll a and b in the same proportions as the 'higher' plants; beta-carotene (a yellow pigment); and various characteristic xanthophylls (yellowish or brownish pigments). Food reserves are starch, some fats or oils like higher plants.
Algae are unicellular or multicellular organisms (formerly classified as plants) that have chlorophyll but lack true stems, roots, and leaves. Algae include the seaweeds, diatoms, and spirogyra. Prokaryotic Organisms-The Cyanobacteria Cyanobacteria belong to Domain Bacteria. These microscopic organisms lack nuclei. They were once classified as algae because they have chlorophyll a. This explains why they are often referred to as the blue-green algae.