Download Pop Bead Meiosis Lab

Pop-Bead Meiosis Lab
Class Set
MEIOSIS I
Interphase I:
A. Construct 1 strand of 10 pop-beads that is all one color.
Top of bead
a) This represents a segment of DNA from the mother that codes for
specific traits.
B. Using another color, construct 1 strand of 10 pop-beads.
a) This represents a segment of DNA from the father that codes for the
Bottom of bead
same traits as the first strand.
b) They are the same length and code for the same traits (ex-eye color).
c) However, they may code for different versions of those traits (ex-blue or brown eyes).
C. Using a color different from the previous 2 strands, construct a third strand of only 6 pop-beads.
a) This represents a segment of DNA from the mother that codes for specific traits. These traits
are different from the first strand, evident by the different length.
D. Now, using a 4th color, create another strand that is 6 pop-beads long.
a) This represents a segment of DNA from the father that codes for the same traits as the
previous 6 bead strand.
b) They are the same length and code for the same traits (ex-hair color).
c) However, they may code for different versions of those traits (ex-black or red hair)
& CHECK You should now have 4 strands, each that is a different color, 2 strands should be 10
beads long and the other 2 should be 6 beads long.
E. Draw a circle with chalk on the desk and place the DNA in the center of the circle which represents the
nucleus. Draw another large circle around that to represent the cell membrane
F. DNA replication occurs during S phase, producing a duplicate of the DNA. Construct identical stands to
the ones previously made.
G. Join the identical strands at the centromere to form a pair of sister chromatids. The centromere is
represented by a tan, magnetic bar. You will need to add the centromere bead above the middle of the
strands. Repeat for all 4 of the chromosomes.
IN YOUR NOTEBOOK, LABEL THIS SECTION: INTERPHASE I
Draw a picture of the cell with chromosomes mixed together in the nucleus. The drawing
should include each pop bead and color. Don’t forget to label.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn
individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
Prophase I
A. The nucleus is dissolving. Remove sections of the nucleus from the cell on the desk, making it dotted.
The centrioles and small spindle fibers should appear off to the side.
B. In prophase I, homologous chromosomes (chromosomes with the same lengths & genes) move close
together and pair up along their entire length. A tetrad (group of 4 chromatids) is formed. Form tetrads
and entwine the homologous pairs.
C. Simulate crossing over by removing a few pop-beads from one area of one of the chromosomes and
replacing it with the corresponding pop-beads of the other homologous chromosome. Do this for all
pairs of homologous chromosomes.
IN YOUR NOTEBOOK, LABEL THIS SECTION: PROPHASE I
Draw a picture of the cell in prophase I with the homologous pairs lined up next to each other
after having undergone crossing over.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
Metaphase I
A. In this phase the chromosomes are pulled by the spindle fibers until they line up along the imaginary
metaphase plate. Disentangle your chromosomes, and align the homologous chromosome pairs side by
side at the metaphase plate. The long homologous pair should be together and the short pair should be
together. Draw two centrioles at either end of the cell and spindle fibers should be connected to the
chromosomes at the centromere.
IN YOUR NOTEBOOK, LABEL THIS SECTION: METAPHASE I
Draw a picture of the cell in metaphase I with the homologous pairs lined up along the metaphase
plate.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
Anaphase I
A. The homologous chromosomes are separated and drawn towards the centrioles on opposite sides of the
cell by the spindle fibers. One long and one short chromosome pair should be found on each side.
B. Move the chromosomes by the centromeres; noting how the chromosome arms trail the centromere as
movement occurs creating an arc with the edges curled towards the center of the cell.
IN YOUR NOTEBOOK, LABEL THIS SECTION: ANAPHASE I
Draw a picture of the cell in anaphase I.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
Telophase I / Cytokinesis I
During meiosis I, cell division occurs resulting in two daughter cells still containing paired chromatids.
A. During Telophase I the nucleus begins to regrow and the spindle fiber retract and the centrioles move
out of the way. Cytokinesis begins during Telophase. Cytokinesis consists of the original cell breaking
into two new cells.
B. Create two cellular membranes by erasing the original circle and drawing two circles around the newly
paired chromosomes. You will draw this on the lab table but DO NOT draw this in your journal as it
will look very similar to Prophase II(the next step).
MEIOSIS II
Prophase II
The chromosomes move toward the center of the daughter cells. Centrioles move to the opposite ends of the
cell.
A. Place the chromosomes in the center of each daughter cell. Then make the nucleus a dotted line to show
that it is disappearing.
IN YOUR NOTEBOOK, LABEL THIS SECTION: PROPHASE II
Draw a picture of Prophase II. Drawing should include each pop bead, color and labels.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
3. Label each cell as DAUGHTER CELL #1 and DAUGTHER CELL #2
Metaphase II
All of the chromosomes line up, single file, in the center of the cell.
A. Center the chromosomes along an imaginary line across the center of the cell.
IN YOUR NOTEBOOK, LABEL THIS SECTION: METAPHASE II
Draw a picture of metaphase II. Drawing should include each pop bead, color and labels.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
3. Label each cell as DAUGHTER CELL #1 and DAUGTHER CELL #2
Anaphase II
The chromosomes of each paired strand separate at the centromere and are drawn to opposite poles of the cell.
A. The centromere is broken and the chromosomes are separated. The individual chromosomes are drawn
towards opposite sides of the cell by the spindle fibers. Break the centromeres leaving the individual
chromosomes next to each other in the center of the cell.
B. Separate each chromosome, moving them towards the centrioles by pulling only the remaining piece of
centromere. Move the chromosome by the centromeres; noting how the chromosome arms trail the
centromere as movement occurs creating an arc with the edges curled towards the center of the cell.
C. Repeat this procedure for both daughter cells.
IN YOUR NOTEBOOK, LABEL THIS SECTION: ANAPHASE II
Draw a picture of anaphase II. Drawing should include each pop bead, color and labels.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
3. Label each cell as DAUGHTER CELL #1 and DAUGTHER CELL #2
Telophase II / Cytokinesis II
Cell division is completed and four daughter cells are formed. Each contains half of the chromosome number
of the original parent cell. A nuclear membrane forms around each cell’s chromosomes and the daughter cells
finish dividing. Here we are skipping the telophase step and showing you the final results of Telophase II and
Cytokinesis II.
A. Erase the original 2 circles and draw four circles to represent each of the new cells. Then draw a circle
around each of the chromosome sets inside the new cells to represent the nucleus of the each cell. The
centrioles and spindle fibers will not be in this illustration. There should be one long and one short
chromosome in each of the new cells.
IN YOUR NOTEBOOK, LABEL THIS SECTION: TELOPHASE II/CYTOKINESIS II
Draw a picture of telophase II / cytokinesis II. Drawing should include each pop bead, color and
labels.
1. Include all drawings (with color) in your journal.
a) Each illustration of the pop-beads requires each bead to be drawn individually.
b) Cell membranes are to be drawn using the petri dish as a template.
2. You will need to label the following things in each drawing if they are present:
homologous chromosome #1, homologous chromosome #2, sister chromatids, cell
membrane, spindle fibers, centrioles, nucleus, centromeres
3. Label each cell as DAUGHTER CELL #1 and DAUGTHER CELL #2
Conclusion Questions: Answer in detailed, Pre-AP high level, complete sentences.
1. Give a detailed explanation of why crossing over does not happen during mitosis.
2. The sister chromatids of the daughter cell may be different from the sister chromatids in the parent
cell. Why? Give a detailed explanation.
3. What occurs in prophase I that doesn’t happen in prophase II of meiosis? Explain.
4. It would have been much easier to simulate mitosis. Give two detailed ways the process of meiosis
differs from mitosis.
5. What is the general name of cells produced by mitosis? AND Produced by meiosis?
6. In what step of meiosis is there a reduction in the chromosome number?
7. Differentiate between homologous chromosomes and sister chromatids.
8. Differentiate between haploid and diploid.