B. 245 million
from the end of Carboniferous Period to the beginning of the Triassic period
Answer:
D. Dehydration synthesis
Explanation:
Cells build carbohydrate polymers by using energy to form glycosidic linkages, the bonds between monosaccharides. A dehydration synthesis reaction forms a bond between carbon atoms in two monosaccharides, sandwiching an oxygen atom between them and releasing a water molecule.
Pi and sigma bonds
Pi is double bonds and sigma is single bonds
I think I found your question online and if the questions are the same, the answers would be A. B. and C. Once again, you do not have to take this answer because I am unsure if I found the same chart that you have.
The endocrine system uses chemicals