We should expect that the rat will have have more difficulty in learning the task compared to a normal rat. This is because the rat has been injected with a certain drug that oppresses the dopamine activity. And then the rat is placed in an operant chamber where a lever-pressing task is shaped through positive reinforcement.
If a p53 gene is defective it may cause cell cycle to stop functioning normally. Without this cell cycle check, cells will divide continuosly creating many chromosomal damage.
Many different ways, primarily through bone and muscle loss. The lack of pressure on bones causes the body to reabsorb calcium from them, weakening them and potentially causing kidney stones.
Answer;
-The conservation of "junk DNA" sequences in diverse genomes suggests that they have important functions.
Explanation;
-The term junk DNA refers to regions of DNA that are noncoding. DNA contains instructions (coding) that are used to create proteins in the cell. However, the amount of DNA contained inside each cell is vast and not all of the genetic sequences present within a DNA molecule actually code for a protein.
-Some of this noncoding DNA is used to produce non-coding RNA components such as transfer RNA, regulatory RNA and ribosomal RNA. However, other DNA regions are not transcribed into proteins, nor are they used to produce RNA molecules and their function is unknown.
