Answer:
Watson and Crick were able to develop a more accurate molecular structure because they had access to x-ray crystallography! Pauling didn't actually failed, he just did't have the same means!
Explanation:
By the way, is now known that the real discovery of DNA molecule was made by Rosalind Franklin. Any doubts you can send me a message!
When stem cells grown on hard, rigid surface, then they became bone cells. Researchers demonstrate in Nature materials that human mesenchymal stem cells grown on a rigid substrate for some time become biased toward differentiating into bone-cell lineage, whereas cell grown on softer surfaces are just likely to eventually follow a bone or fat cell fate.
Endocrine gland - a group of cells that secretes substances into the blood or directly into an organ.
Differ from exocrine glands, endocrine glands have no ducts and secrete products (hormones) directly into blood.
Hormone - a substance produced by cells that helps specific groups of cells to perform specific functions. It is a product of endocrine gland which functions as chemical messengers to stimulate other cells.
Duct – a channel or tube that conveys a substance. It is part of the exocrine glands (such as salivary glands) which makes contact with surface .
I believe the answer id Cnidaria
