By listening to radioactive waves
The correct answer is: mucosa
The alimentary canal or gastrointestinal tract consist of four layers: mucosa, submucosa, muscular layer and serosa.
Mucosa is the layer that surrounds the lumen, so it is exposed to the food . Mucosa is composed of epithelium (active in absorptive and secretory processes), lamina propria (connective tissue) and muscularis mucosa (peristaltic movement).
Answer:
greater than
Explanation:
the mass of an object is basically how big the watermelon is. usually, watermelons weigh more than 9 kg. imagine going to walmart and picking up a watermelon. at first glance, its purty huge. of course the the mass of an object, the more the weight of said object. since watermelons are pretty big, the overall mass is going to be big as well.
The lipids form an insoluble barrier.
Phospholipids, a type of lipids, don’t dissolve in water. Membrane-forming lipids have like other lipids hydrophobic region, but also in addition, they have hydrophilic region. In the cell membrane, they are organized in a lipid bilayer. In each layer, hydrophilic heads face a solution, and hydrophobic tails are inside the layer. That way, phospholipids are in contact with water, but still present a barrier because of their hydrophobic tails inside the layer.
