"Lab 11 Mitosis Lab Report
Scroll to the bottom and click on Procedure for Experiment
1: Observation of Mitosis in a Plant Cell
Table 1: Mitosis Predictions
Stages Hours in each stage
After observing the onion root tips, count the number of cells in each stage and report below
Table 2: Mitosis Data
Stages Number of Cells counted in Each Stage % of cells in each stage
(# cells in stage/total# cells in field times 100) Hours in each stage
(24 x %)*
Total cells counted
*(Note to multiply by a % you divide the % by 100)
Table 3: Stage Drawings
Cell Stage: Describe what is happening in each stage, include a picture if you want.
Answer the following questions
1. Label the arrows in the slide image below
Labels from the diagram above
2. In what stage were most of the onion root tip cells in? Based on what you know about cell cycle division, does this make sense? Explain why or why not.
3. Were there any stages of the cell cycle that you did not observe? How can you explain this using evidence from the cell cycle?
4. As a cell grows, what happens to its surface area: volume ratio? (Hint: Think of a balloon being blown up). How does this ratio change with respect to cell division?
5. What is the function of mitosis in a cell that is about to divide?
6. What would happen if mitosis were uncontrolled?
7. How accurate were your time predication for each stage of the cell cycle?
8. Discuss one observation that you found interesting while looking at the onion root tip cells.
Experiment 2: Tracking Chromosomal DNA Movement through Mitosis
Complete the experiment 2, tracking Chromsomal DNA Movement through Mitosis complete the following tables and questions
Cell Cycle Division: Mitosis Beads Diagram or pictures of your beads
1. How many chromosomes did each of your daughter cells contain?
2. Why is it important for each daughter cell to contain information identical to the parent cell?
3. How often do human skin cells divide? Why might that be? Compare this rate to how frequently human neurons divide. What do you notice?
4. Hypothesize what would happen if the sister chromatids did not split equally during anaphase of mitosis.
1. In a species of mice, brown fur color is dominant to white fur color. When a brown mouse is crossed with a white mouse all of their offspring have brown fur. Why did none of the offspring have white fur?
2. Can a person’s genotype be determined by their phenotype? Why or why not?
3. Are incomplete dominant and co-dominant patterns of inheritance found in human traits? If yes, give examples of each.
4. Consider the following genotype: Yy Ss Hh. We have now added the gene for height: Tall (H) or Short (h). How many different gamete combinations can be produced?
1. Set up and complete Punnett squares for each of the following crosses: (remember Y = yellow, and y = blue)
Y Y and Y y
Gamete alleles Y Y
Now you do this one Y Y and y y
a) What are the resulting phenotypes?
b) Are there any blue kernels? How can you tell?
2. Set up and complete a Punnett squares for a cross of two of the F1 from 1b above
a) What are the genotypes of the F2 generation?
b) What are their phenotypes?
c) Are there more or less blue kernels than in the F1 generation?
Part 2 and 3 Section A. Monohybrid cross
• Pour the 50 yellow (Y) and 50 blue (y) beads into a beaker. Without looking randomly take 50 beads from the beaker and place them in the smaller 100 ml beaker. Label this as beaker #1
• Do not make a beaker 2 as we are not completing the dihybrid part of the experiment.
1. What is the gene pool of beaker #1? (colors)
2. What is the gene frequency of beaker #1, (example 26 blue: yellow, you’ll have to count yours)
Directions: Randomly (without looking) take 2 beads out of #1.
• This is the genotype of individual #1, record this information on table below. Do not put those beads back into the beaker.
• Repeat this for individual #2. These two genotypes are your parents for the next generation. Set up a Punnett square and determine the genotypes and phenotypes for this cross.
• Repeat this process 4 times (5 total). Put the beads back in their respective beakers when finished.
Trial Parent 1
genotype Offspring from cross
(Note examples of your answers in green) Beads
genotype: YY Beads
Yy Genotypes from your Punnett square
a) How much genotypic variation do you find in the randomly picked parents of your crosses?
b) How much in the offspring?
c) How much phenotypic variation?
d) Is the ratio of observed phenotypes the same as the ratio of predicted phenotypes? Why or Why not?
e) Pool all of the offspring from our 5 replicates. How much phenotype variation do you find?
f) What is the difference between genes and alleles?
g) How might protein synthesis execute differently if a mutation occurs?
h) Organisms heterozygous for a recessive trait are often called carriers of that trait, what does that mean?
i) In peas, green pods (G) are dominant over yellow pods. If a homozygous dominant plant is crossed with a homozygous recessive plant, what will be the phenotype(appearance) of the F1 generation? If two plants from the F1 generation are crossed, what will the phenotype of their offspring be?
Looking at 2 traits instead of just one
3. Identify the four possible gametes produced by the following individuals
a) YY Ss
b) Yy Ss
c) Create a Punnett square using these gametes as P and determine the genotypes of the F1
d) What are the phenotypes of this generation? What is the ratio of those phenotypes?
Other Requirements: I will one more time apreciate your time in answearing this if you can. good tip available."