View the animation below, then complete the quiz to test your knowledge of the concept.

1	The sequence for smooth muscle contraction is...
	A)	increased cytosolic calcium, which binds to troponin, complex binds with myosin light-chain kinase, which uses ATP to phosphorylate myosin cross-bridges, which bind to actin filaments, resulting in contraction.
	B)	increased cytosolic calcium, which binds to calmodulin in cytosol, which binds with myosin cross-bridges, resulting in contraction.
	C)	increased cytosolic calcium, which binds to calmodulin in cytosol, which moves tropomyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in contraction.
	D)	increased cytosolic calcium, which binds to troponin, which moves tropomyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in contraction.
	E)	increased cytosolic calcium, which binds to calmodulin in cytosol, complex binds with myosin light-chain kinase, which uses ATP to phosphorylate myosin cross-bridges, which bind to actin filaments, resulting in contraction.
2	The sequence for skeletal muscle contraction is...
	A)	increased cytosolic calcium, which binds to troponin, complex binds with myosin light-chain kinase, which uses ATP to phosphorylate myosin cross-bridges, which bind to actin filaments, resulting in contraction.
	B)	increased cytosolic calcium, which binds to calmodulin in cytosol, which binds with myosin cross-bridges, resulting in contraction.
	C)	increased cytosolic calcium, which binds to calmodulin in cytosol, which moves tropomyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in contraction.
	D)	increased cytosolic calcium, which binds to troponin, which moves tropomyosin from blocking active sites on actin filament, which binds with myosin cross-bridges, resulting in contraction.
	E)	increased cytosolic calcium, which binds to calmodulin in cytosol, complex binds with myosin light-chain kinase, which uses ATP to phosphorylate myosin cross-bridges, which bind to actin filaments, resulting in contraction.
3	Which of the following statements is true concerning calcium ions?
	A)	in smooth muscle it binds with calmodulin.
	B)	in skeletal muscle it binds with calmodulin.
	C)	in smooth muscle it binds with troponin.
	D)	in skeletal muscle it binds with tropomyosin.
	E)	in smooth muscle it binds with myosin light-chain kinase.
4	Smooth muscle and skeletal muscle fibers both have their contractions triggered by calcium ions.
	A)	True
	B)	False
5	Both smooth muscle contractions and skeletal muscle contractions involve thin (actin) filaments sliding over the thick (myosin) filaments.
	A)	True
	B)	False