Question

Which of the following is not true about rigor mortis?
A.It is irreversible.
B.It is not a permanent contraction.
C.ATP increases in muscles.
D.Time of onset is not the same in all muscles.

Answer 1

Hint: Rigor Mortis is the third stage of death. It is a recognizable change which occurs after death causing the stiffening of body muscles.

Complete answer:
Let us analyze the options to find out the correct option.
Option A: Rigor Mortis is an irreversible change. Its effects cannot be reversed. Hence, this is the incorrect option.
Option B: Rigor mortis is a contraction which is at peak 12 hours after death and disappears after 48 hours. It is not permanent and leaves the body. Hence, this is the incorrect option.
Option C: After death, there is no oxygen and hence the body cannot produce ATP. Due to this action myosin cannot separate. Then ATP is produced by anaerobic glycolysis which causes depletion of glycogen and thus ATO concentration also reduces. Therefore, this is the correct option.
Option D: Rigor mortis is not the same for all body muscles. Hence, this is the incorrect option.

Hence, the correct answer is option (C)

Note: Rigor mortis starts 1-2 hours after a person’s death. It is the development of rigidity in muscles after the death and can be used to estimate the time of death.
It causes the muscles to become stiff and inflexible.
It is a chemical change.