A signal reaches a cell mostly in the form of a signalling molecule binding to a receptor on the cell surface. This binding activates a chain of events that amplifies the signal and transfers it inside the cell. Protein kinases phosphorylate proteins and cause their activation or deactivation, or in general modify their activity. When a signalling molecule binds to a receptor, a cascade is activated and the second messengers, such as cAMP, are synthesized. cAMP molecules activate the protein kinases, which phosphorylate specific proteins and activate them.
Answer is (A) She needs to know the genotype of the second plant.
Cells divide for many reasons. For example, when you skin your knee, cells divide to replace old, dead, or damaged cells. ... When organisms grow, it isn't because cells are getting larger. Organisms grow because cells are dividing to produce more and more cells.
<span>Connective tissue supports the framework of the liver, and epithelial tissue protects the liver.
Connective tissue holds the liver in place during movement, and epithelial tissue forms the lining of the liver.
Connective tissues are mainly used in forming support networks within tissues and Epithelial tissue tend to line the organs and form protective cell layers.</span>
