By looking for the presence of the germ layers and the primitive gut in the embryo
The answer is 12.5%.
Each gram of protein has four calories. Therefore, 50 grams of protein contain 200 calories. In order to find the percentage of total energy intake that comes from protein, we need to do the division: 200/1600 * 100 = 12.5. Protein is needed for body growth and maintenance and energy.
All living things have DNA within their cells
So Yes
Hope that helped