Lifespan - could be due to predators and food intake
Answer: Backdating the time required for food found in the stomach of the deceased to digest. Since digestion can't continue after death.
Explanation: The time taken for food to get digested can be employed to depicts time of death. This process involves understanding the period of time that usually takes the food found in the gastric of the deceased to calculate the time of death.
Different foods has varying time of digestion, so therefore, the gastric content is a good indicator to determine time of death by the doctor who is carrying out autopsy, since digestion does not continue after death.
However, it is established by scientist that food takes up to 4-6hours in the stomach depending on the size and type of food. Hence, if the status of the food found in the deceased stomach is noted accordingly and the time taken requires for digestion is also noted، the doctor can deduce the time of death accordingly from this two points.
Because fish need light to see
The answer is: Molecule and Organ system. Hope this helps!