2. Which structures must be present in a cell for osmosis to take place? A. Cell (sap) vacuole and cell wall
B. Cell wall and cell membrane
C. Chloroplast and cytoplasm
D. Cytoplasm and cell membrane

D- Chloroplast and cell membrane

answer: 20 percent

the fish culture has become a developing commercial practice in developing countries which is already prominent in developed countries of the world. the major fish protein demand is being supplemented in developing countries is   fishing to meet the needs of the growing population. therefore, in some developing nations, the percentage of animal protein from fish in the diet can be as high as 20 percent.