Which step of cross-bridge cycling is considered the power stroke?
a. when the myosin cross-bridge forms
b. when atp binds to the myosin head and releases it from the thin filament
c. when the phosphate is released and the myosin cross-bridge moves to the right in the animation
d. when atp is hydrolyzed and the myosin head moves to the left in the animation

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.

Why do mountaineers become breathless as they reach high altitudes

What are the two functions of the respiratory system