You create double mutant cells with the permanently active PK1 and an inactivated PK2. You find the cells still respond even when no signal is present. In the normal kinase cascade, does PK1 activate PK2 or does PK2 activate PK1

Explanation:

Normally, PK2 activates PK1

the major parts of the digestive system:

salivary glands.

pharynx.

esophagus.

stomach.

small intestine.

large intestine.

rectum.

accessory digestive organs: liver, gallbladder, pancreas.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.