Answer:
What sends oxygenated blood back to the heart from the lungs?
Oxygen-rich blood flows from the lungs back into the left atrium (LA), or the left upper chamber of the heart, through four pulmonary veins. Oxygen-rich blood then flows through the mitral valve (MV) into the left ventricle (LV), or the left lower chamber.
Explanation:
Non polar molecule move across a membrane through simple diffusion, when moving up their concentration gradient. Simple diffusion involves movement of molecules through a membrane without the help of integral membrane protein. These molecules are driven by the force of diffusion. This is different from facilitated diffusion where molecules only move with the aid of integral protein in the membrane.
Mrs. Lopez has the most difficulty initiating digestion of proteins after her stomach is removed. The correct option is C.
Explanation:
When the stomach is removed due to complications such as in cancers the food eaten directly goes to intestine. Without stomach Mrs Lopez will have difficulty in starting the digestion of protein.
The digestion of protein takes place and starts in the stomach and duodenum of intestine. There are enzymes as pepsin, trypsin and chyomtrypsin secreted by stomach and pancreas. Pepsin breaks the peptide bonds of protein.
The HCl and the enzymes in stomach initiates the process of digestion of protein. The amino acids formed are ardent in various metabolic processes and repair.
lipids and carbohydrate digestion starts from the mouth only as salivary amylase and lipase initiates the process.
Answer:
plants, particularly in terrestrial ecosystems, and algae in aquatic ecosystems. If the plants or other producers of an ecosystem were removed, there would be no way for energy to enter the food web, and the ecological community would collapse.
All food chains begin with producers
