DNA Replication

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Digestion Problem Set 1.Heterotrophs "“ an organism that requires pre-formed organic molecules for food Autotrophs "“ an organism that lives exclusively on inorganic materials 2.Phototrophs "“ organisms that receive their energy from light Chemotrophs "“ organism that receives its energy from carbon dioxide 3.Herbivores "“ organisms who receive their energy from plants Carnivores "“ organisms who receive their energy from other organisms Saphrophytic "“ organisms who receive their energy from the decomposition of other organisms Omnivorous "“ organisms who receive their energy from plants and other organisms 4.

A.Ingestion - Food is inserted into the oral cavity, mechanically broken down by the teeth, and chemically broken down by saliva. The smaller food particles form a bolus, and the bolus is pushed into the pharynx by swallowing. The bolus is then pushed into the esophagus and down to the stomach by peristalsis.

B.Digestion "“ Pepsin in the stomach breaks down the bolus into smaller particles creating chime.

The chime is then pushed through the pyloric sphincter into the duodenum. In the duodenum, the acidic pH of the chime is neutralized. The particles are then pushed into the small intestine where nutrients are absorbed by villi. The leftover material is then pushed into the large intestine where water and salts are absorbed. The left over fecal material is then stored until it is eliminated through the anus.

C.Transportation of food "“ The food is pushed through the body through voluntary muscle contractions like swallowing, or involuntary muscle contractions like peristalsis.

D.Assimilation of food "“ Refers to the construction of nutrients from smaller sub-units, which are to be used by the body.

E.Oxidation of food "“ Refers to the breakdown of food through catabolism.

F.Storage of food "“ Refers to the storage of nutrients in the form of fat...