The answer is A because the heart pumps blood from the heart through pulmonary artery that is low in oxygen and high in carbon dioxide concentration, to the lungs.
Diffusion occurs because of the movement of molecules from the region of higher concentration to the region of lower concentration. This movement of molecules occurs due to a thermal motion. Diffusion normally occurs between two compartments having difference in concentration. In case of fluid it moves from the region of higher concentration to the region of concentration until a balance is reached. The process of diffusion is very important for the humans as well. The oxygen that humans breathe in gets diffused with the blood.<span>
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Depending on the structure of cells (shapes and organelles) we can differentiate cells and therefore create different groups and classifications based on their differences and functions.
The eukaryote-prokaryote division bases itself on the possesion of a nucleus that creates a boundary for the genetic materifal. In this case, eukaryotes have it while prokaryotes don't.
Hope it helped,
BiologiaMagister
When the bread and butter is in mouth, mechanical digestion starts. The size of the food gets reduced and it mixes with saliva for easy swallowing. The salivary amylase in saliva begins the digestion of starch in the bread. This is the start of chemical digestion. When the undigested bread and butter reached the stomach, lower esophageal sphincter relaxes and allow the chewed food to enter. The gastric secretions containing HCl, acts on the undigested food to produce chime. HCl kill the microorganism on the food and also denatures the protein and later attacked by digestive enzyme pepsin. Pepsin breakdown protein in the bread, butter . Later on gastric lipase begins to digest fat present in butter. Digestion of the starch in bread does not occur in the stomach because the salivary amylase that began chemical digestion in mouth became inactive in the presence of HCl. Further the chime enters the small intestine where bile secreted by the gall bladder emulsifies the fat and break into small globule which helps in fat absorption.
