The process of taking in oxygen and releasing carbon dioxide is called: MCQ with Answer and Explanation

Explanation:
The phylum Echinodermata (spiny-skinned animals like starfish, sea urchins, sea cucumbers) is uniquely characterized by a water vascular system used for locomotion, capture and transport of food, and respiration. The tube feet are the terminal effectors of this system. They exhibit secondary radial symmetry in adults, though their larvae are bilaterally symmetrical. Mollusks have a muscular foot, and arthropods have jointed appendages.

Explanation:
Lamarck proposed that organs used extensively develop and those not used degenerate, and these acquired traits are inherited (inheritance of acquired characters). Darwin's theory is natural selection, Wallace independently proposed natural selection, Weismann disproved Lamarckism.

Explanation:
Digestion converts complex, insoluble food molecules into simple, soluble forms that can be absorbed. It involves mechanical action (chewing, churning) and enzymatic hydrolysis. Absorption is the uptake of nutrients, assimilation is incorporation into body tissues, egestion is elimination of undigested waste.