Need urgent Biology questions???

Posted on 2016-05-18 18:37:00 in Biology by TEZ

1) Human skin cells and human white blood cells of the immune system both perform protective functions. Skin cells function primarily in external physical protection, whereas white blood cells function primarily in internal protection. Nonetheless, both types of cells contain a complete copy of the human genome. Explain how cells can have the same genetic information and yet perform different functions. What prevents skin cells from making all the same proteins of a white blood cell? 

2) At several points in the cell cycle there are checkpoints that control the cell's passage from one phase to the next. If a cell receives a signal at each checkpoint, it continues to the next phase; if it does not receive the signal, the cell does not continue. For example, a growth factor may stimulate a cell to move from G1 into S phase. If no growth factor is present, the cell cycle stops in G1 and the cell does not divide. Predict what would happen to a cell and to a multicellular organism if there was a defect at the checkpoint and the cell continued through the cell cycle even in the absence of a signal.

---

Answer Comment

No Answers Posted Yet.