Identify the trend common to both the 15-day-old and 1-month-old guinea pigs' red blood cells. identify the trend common to both the 15-day-old and 1-month-old guinea pigs' red blood cells. both experienced the most rapid uptake of glucose at the beginning of the experiment. both took up the most glucose during the last incubation interval, from 45 minutes to 60 minutes. both took up approximately the same amount of glucose over the course of the experiment. both experienced a dropoff of glucose levels near the end of the experiment.