Secretion of human chorionic gonadotropin [HCG] only occur during pregnancy in the placenta. The concentration of this hormone increase rapidly during the first three months of pregnancy; the amount in the blood stream doubles every two to three days as the development of the placenta and embryo progress. The hormone reaches its maximum concentration peak around the sixth week of pregnancy and after this, its concentration decline.
The main pigment of plants is "chlorophyll," which gives the green color characteristic of most vegetables, absorbs very well the light in the bands of red and violet, reflecting the green light.
Answer:
Explanation:
Plants use carbon and release oxygen, and animals release carbon and use oxygen.
