Instructor’s Copy
Lab Worksheet – The Great Divide
Draw a cell from under the microscope showing each phase of mitosis.
Anaphase
Telophase
Observations:
Interphase
1. Are a nucleolus and nuclear membrane present? Yes
2. Are distinct rod-shaped structures called chromosomes easily observed in the nucleus at this
time? No
Prophase
3. Are chromosomes visible during prophase? Yes
4. Describe changes that have occurred to the nucleolus and nuclear membrane from interphase to
prophase. The membranes have disappeared.
Metaphase
5. Describe where the chromosomes are in relation to the cell. They are at the equator.
6. Can evidence of chromosome duplication (replication) be observed? (This depends on their
cells.)
7. Do you see a nuclear membrane? No.
8. Are spindle fibers present? Yes.
Anaphase
9. What evidence can now be observed to support the fact that the chromosomes have duplicated
(replicated)? There are twice as many chromosomes pulling apart.
10. Toward what area of the cell are the chromosomes being directed? The poles.
11. Can you see two distinct sets of chromosomes? Yes.
12. Does it look like the number of chromosomes at one side of the cell is equal to the number at the
other side? Yes.
Telophase
13. How many cells have now formed from an original cell? Two.
14. Are the two new cells alike? Yes.
15. How does mitosis in the animal cell differ from mitosis in plant cells? The plant cell forms a
cell plate, not a cell furrow.
Analysis
16. What important event happens during interphase? Growth and duplication of the
chromosomes.
17. Explain why distinct chromosomes can be seen in prophase? They thicken and become visible.
18. What term is used to describe the structure to which each fiber attaches to a chromosome?
centromere
19. Explain how the number of chromosomes found in each daughter cell compares to the number
found in the original call. The are the same.
20. What is the difference between mitosis in plants and animals? The plant cell forms a cell plate
to divide the cells while the animal cell pinches to form a cell furrow. Plant cells also do not
have centrioles.