What is the next step in muscle contraction after the actin changes shape

Which of the following statements is true of enzymes? a)they dont provide an active site for substrates to bind in a reaction b)they act on a specific type of substrate in a reaction c)they unusable after a reaction d)they change shape after a reaction

Explain how fossils scientists make discoveries about the lives of organisms and about how environments have changed over time. plz hurry up it time

What are the pros and cons of quadrat sampling?