Cell Division Date 3/ 7/ 11

Today we began the class by working on our cell division worksheet with the onion ring. We are using microscopes in order to answer the questions on this worksheet. Mr. Finley reminded us that the onions we are using are not necessarily going through metaphase. Then, one of our classmates asked a very good question which was, "When we looked at grass cells and onion cells before, why didnt we expect to see mitosis?" Then Mr. Finley explained to us that we are now looking at the root of the onion. And we expect to see mitosis now because the root collects nutrients and water for the onion in order for the onion to grow and develope. This is why we expect to see it go through mitosis. Under low power of the microscope we saw one big circle that had hundereds of other really light circles. Inside each of the little circles we saw a darker circle in the middle and in the middle of that we saw a black dot. When we switched it to high power we saw in greater detail, the lighter circles. And we believed that those were the cell membranes of the cells. Inside that we saw a darker brownish circle that we believed was the nucleus of the cell. Lastly, in the center of that we saw a smaller black circle. And we believe that the black dot could potentially be the DNA (deoxyribo nuclaic acid). Our group also something quite peculiar. We saw that we saw a cell had two black circles and we believed that it was quite interesting. Our group had found several stages in our onion. We found anaphase, telephase, interphase, and prophase. We noticed that some cells were bigger than others. Which are signs of mitosis occuring.

Today was a great day because it really got my group and I thinking and understanding the stages of cell division.

BY,
LB