SBI3U
GENETICS
Name:_________________________
OBSERVING MEIOSIS
INTRODUCTION:
A diploid cell undergoes two divisions during meiosis, producing four haploid cells. While the large numbers of
chromosomes in most cells make observation difficult, it is possible to identify the main phases of meiosis.
In this investigation, you will examine cells undergoing meiosis and document your findings by creating
biological drawings. You will be examining the formation of male gametes in grasshopper testes-the site of
sperm production.
PURPOSE:
To investigate the process of meiosis through observation and to draw biological diagrams to help explain the
main phases in the process.
MATERIALS:
 Prepared slides (grasshopper testes)
 Microscope
PROCEDURE:
1. Obtain a microscope and a prepared slide of grasshopper testes cells undergoing meiosis. Take
several minutes to carefully survey a large number of cells. This will help you locate regions where
meiosis is most active.
2. Using the high-power objective lens, locate a group of cells that are undergoing meiosis (the
chromosomes should be clearly visible).
3. Observe Figure 1 below and label the phases of meiosis using class notes.
4. Using the images in Figure 1, identify the various phases of meiosis the cells on your slide are
undergoing.
5. Create biological drawings for two or more cells undergoing meiosis. Make note of which phase of
meiosis each cell is in and record this on your drawing. Be sure to properly identify and label the
structures on your drawings.
Figure 1: Photomicrographs of cells in meiosis
Name:
Date:
Title:_________________________________________________________
Magnification:
Specimen Size:
ANALYZE AND EVALUATE
1. What cell structures were you able to observe in this investigation? How did you use their appearance
to determine cellular activity?
(2 marks)
2. What difficulties did you experience in performing this investigation (list at least two)? Explain.
(2 marks)
3. Which two meiotic events ensure genetic recombination and increase genetic diversity within a
species? Briefly explain each, and identify the phase of meiosis in which the event occurs.
(5 marks)
4. Were you able to observe crossover events? Explain.
(2 marks)
5. On the other side of this page draw a diagram of a cell with six chromosomes (single stranded) that
undergoes all phases of meiosis.
a. Use different colours to represent homologous pairs.
b. Be sure to include cross-over events, and the daughter cells in your diagram must include the
correct sections of the original parental chromosomes.
c. Include spindle fibers, centrioles and all other relevant structures.
d. Label all structures.
Prophase I
Metaphase I
Anaphase I
Telophase I
Prophase II
Metaphase II
Anaphase II
Telophase II
SBI3U
Name:_________________________
GENETICS
/50
OBSERVING MEIOSIS: MARKING SCHEME
DRAWING:
 Done in pencil:
 Accurate Labeling:
 Accurate Drawing:
 All information included:
/1
/4
/4
/2
ANALYSIS:
 Photomicrographs accurately labeled:
 Discussion questions complete:
/4
/11
MEIOSIS DIAGRAM:
 Accuracy:
 Colour coding continuity:
 All structures labeled:
 Drawing neat and easy to follow:
/8
/8
/4
/4
SBI3U
Name:_________________________
GENETICS
/50
OBSERVING MEIOSIS: MARKING SCHEME
DRAWING:
 Done in pencil:
 Accurate Labeling:
 Accurate Drawing:
 All information included:
/1
/4
/4
/2
ANALYSIS:
 Photomicrographs accurately labeled:
 Discussion questions complete:
/4
/11
MEIOSIS DIAGRAM:
 Accuracy:
 Colour coding continuity:
 All structures labeled:
 Drawing neat and easy to follow:
/8
/8
/4
/4