109 exact :D hope this helped! Have a good day
Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
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Answer:b. cellulose; cell walls of plants
Explanation: polysaccharides are polymers of monossacharides.they are the most abundant organic substance.it is found in the cell walls of plants . cellulose is a linear polymer of glucose residues.cellulose is an important component in the diet of herbivores and omnivores.they do not produce the cellulase enzyme for digesting cellulose.as a result,they depend on symbiotic relationship with bacteria and protozoa found in their stomach to produce cellulase.
This process is called as imprinting. It occurs at a particular stage of life and is, therefore, a phase-sensitive learning process. It can be of many types, including filial imprinting, where an offspring gains some of its behavioral characteristics from the parent, or sexual imprinting, through which desirable characteristics of a mate are recognized by a young animal.
