The answer would be "<span>Cyclins are proteins that regulate when and how often a cell divides". Cyclins belong to a family of proteins that control the progression of a cell through its respective cell cycle. This is initiated by activating cyclin-dependent kinase (CDK) enzymes which regulate </span>transcription of RNA and process mRNA during mitosis.
Lashley is looking at different ways in which the brain works, especially different parts of the brain. If part of the brain was damaged and you compare how well the rat completed the task before and after the damage, then you can determine what function that part of the brain does. Also, if you study how well the rat completes the task as time progress, you can see if the rat is able to use other parts of the brain to "learn" and repair the damaged part of the brain.
B is the answer since it needs to be improved
