Mitosis Lab

Mitosis/Meiosis Lab

	Field 1	Field 2	Field 3	total cells in phase	fraction of total count	estimated time of stage
Interphase	600	750	800	2150	.96	23hrs 2 min
Prophase	24	20	12	56	.02	28 mins 48 secs
metaphase	8	4	11	23	.01	14 mins 24 secs
anaphase	0	1	2	3	.001	1 min 26 secs
telophase	1	12	3	16	.007	10mins 5 secs
total	633	787	828	2245

The importance of mitosis is that it produces two daughter cells that are each

genetically identical to the original cell. Explain how mitosis accomplishes this.

Include the relevant events that occur in interphase.

-----In metaphase, all genetic information is lined up and copied, so when anaphase begins each new nucleolus gets equal copies of the original genetic information.  

A cell has 32 chromosomes. It divides by mitosis to produce two daughter cells.

How many chromosomes does each daughter cell have? 32

2. Based on your data and pie graph, what do you infer about the relative length of

time an onion root tip spends in each phase of mitosis?

The majority of time is spent in interphase, and all other phases go rather quickly.

3. In Table 3.1, if your counts had included parts of the onion root tip in which cells

were not actively dividing, how might this have changed your results?

Much more of the cells observed would have been in interphase, rather than in any of the other phases.

Using Table 3.2 and reflecting on what you have learned in this lab, list three major

ways that mitosis and meiosis differ.

Meiosis has tetrad linking, Meiosis goes through prophase, metaphase, anaphase, and telophase for a second time, and meiosis occurs during child formation, or within the sexual organs.  

3. How do meiosis I and meiosis II differ?

Meiosis II does not have interphase, Meiosis II is exactly identical to Mitosis, meiosis II is haploid

4. Why is meiosis important for organisms that reproduce sexually?

Meiosis is important for organisms that reproduce sexually because if it wasnt there we would have organisms with too many genes thus creating non-human beings. Meiosis allows the child to have genes of both the parents.