Please find the answers and explanations below: Part A: The qualitative images shown show that under normal conditions, a large number of TUNEL positive cells are presnet in the spinal cord representing large amount of cell death. However, in the second image where factor X has been eliminated from the mice, a very few number of TUNEL positive cells have been observed even in the absence of a pro-survival factor Bcl-XL. This suggests that deletion of factor X improves cellular viability in the spinal cord as clearly seen by reduction in TUNEL positive cells. Part B: It can be clearly seen in the images that deletion of factor X reduces the incidences of TUNEL positive cells in the spinal cord of double knock-out mice. This suggets that even in the absence of a factor which promotes cell survival, deletion of factor X promotes cellular viability by showing decrease in appearance of TUNEL positive cells. This data collectively suggests that the factor X has a role in pro-apoptotic cycle of programmed cell death or expression of factor X promotes cell death in spinal cord. Solution Please find the answers and explanations below: Part A: The qualitative images shown show that under normal conditions, a large number of TUNEL positive cells are presnet in the spinal cord representing large amount of cell death. However, in the second image where factor X has been eliminated from the mice, a very few number of TUNEL positive cells have been observed even in the absence of a pro-survival factor Bcl-XL. This suggests that deletion of factor X improves cellular viability in the spinal cord as clearly seen by reduction in TUNEL positive cells. Part B: It can be clearly seen in the images that deletion of factor X reduces the incidences of TUNEL positive cells in the spinal cord of double knock-out mice. This suggets that even in the absence of a factor which promotes cell survival, deletion of factor X promotes cellular viability by showing decrease in appearance of TUNEL positive cells. This data collectively suggests that the factor X has a role in pro-apoptotic cycle of programmed cell death or expression of factor X promotes cell death in spinal cord..