What is a protein that is the main component of the thick filaments in muscle fibers and is responsible for muscle contraction?
actin
myosin
actin and myosin
nerve and bone

What is the phylum of soft bodied animals with a true bosy cavity and a three part body consisting of a foot visceral mass and a mantle

How do accessory pigments chlorophyll?

What is true of all organisms in the kingdoms protista, plantae, fungi, and animalia? a. they are multi-celled. b. they are photosynthetic. c. they have cells that contain membrane-bound organelles. d. they contain cells that lack membrane-bound organelles.