?????? what do u mean by that
I think the correct answer would be A. The yolk sac becomes the placenta. It is membranous sac that is attached to the embryo. It provides all the nutrition and the blood cells needed by the embryo. It is also called the umbilical vesicle.
In my opinion it is diluted and formed into concentrate and is then divided into proportion.
Answer: Carbon 12 and Carbon 13
In plant, the ratio of carbon 12 and carbon 13 isotopes is different depending upon the plant photosynthesis. The distribution of these isotopes in plant tissue can indicate the path way of carbon metabolism that is either C3 fixation or C4 fixation. This help scientist to know if the plant consumed by organism is C3 plant or C4 plant by measuring the isotopic signature of their collagen and other tissues.
This can help scientist know which plant is consumed by animals.
