Question

Which of the following statements about graded response is false?

A. Muscles as a whole can react with different degrees of shortening.
B. Graded muscle contractions can be produced by changing the number of muscle cells being stimulated.
C.Graded muscle contractions can be produced by changing the frequency of stimulation.
D.Muscle cells never fully contract when stimulated.

Answer 1

The false statement about graded response is that muscle cells never fully contract when stimulated. Individual muscle fibers can fully contract during tetanus, a sustained contraction.

Step-by-step explanation:

Among the statements provided about graded response in muscle contractions, the false statement is D. Muscle cells never fully contract when stimulated. This is incorrect because individual muscle fibers, when stimulated enough, can indeed contract fully during a process known as tetanus, where the muscle maintains a sustained contraction. Graded muscle contractions are a product of both altering the number of muscle cells being stimulated (recruitment) and changing the frequency of stimulation.

The combined effect of these mechanisms allows muscles to produce contractions of varying strength. The speed of muscle contractions can vary as the nervous system responds to local conditions and adjusts accordingly.