Which of the following is the correct explanation for the data?
(A) At higher osmolarity, lower rates of contraction are required because more salt diffuses into the paramecia.
(B) The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
(C) The contractile vacuole is less efficient in solutions of high osmolarity because of the reduced amount of ATP produced from cellular respiration.
(D) In an isosmotic salt solution, there is no diffusion of water into or out of the paramecia, so the contraction rate is zero.
Ans: (B) The contraction rate increases as the osmolarity decreases because the amount of water entering the paramecia by osmosis increases.
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