Working out the order in which the individual components in a signaling pathway act is an essential step in defining the pathway. Imagine that two protein kinases, PK-B and PK-X, act sequentially in an intracellular signaling pathway: - When either kinase is completely inactivated, cells do not respond to the normal extracellular signal. - Cells containing a mutant form of PK-B that is permanently active respond even in the absence of an extracellular signal. - Doubly mutant cells that contain inactivated PK-X and permanently active PK-B respond in the absence of a signal. A. In the normal signaling pathway, does PK-B activate PK-X or does PK-X activate PK-B? Explain your reasoning.

In the usual signalling pathway, PK2 triggers and initiates PK1. We can deduce this from the fact that if PKI is fully initiated, a response is seen and the response is seen as not dependent on the status of PK2, which pinpoints to the fact that PK2 is promoted ensuing of PK1. Let's infer that if the experimental setup happened to be altered in such a way as it causes PKI to be mutationally non-functional and PK2 possessed a stimulating mutation, no response can be said to be seen due to the fact that PK2 won't initiate PK1.

that scientist would be robert hooke

answer:

the water molecules are transferred from the roots to the stem or top parts of the tall tree because of important properties of water which are adhesion, cohesion and capillary action. cohesion is the property of water molecules keeps water molecules in a combined state by sharing of bonds between them at the atomic level. adhesion allows the interaction of water molecules with other substances or substrate. adhesion will cause the attachment of water molecules to the wall of the vessel (xylem) of the plant. capillary action occurs when the adhesive force to the vessel wall is stronger than the cohesive force between water molecules. capillary action mimics the transfer of water from a tube or pipe. in this way water utilizes its property to transfer water from down to top level of the plant.