This experiment is being done to show Mendel’s rule of dominance that says certain alleles are dominant and others are recessive. To show this, we are using tobacco seeds, a monohybrid cross comparing only one trait color.
We are also showing Mendel’s law of segregation with a Dihybrid cross comparing two traits of color and texture.
1. To predict the genetic frequency off offspring.
2. To predict the outcomes of genetic crosses using punnett squares.
3. Statistically analyze the results of a genetic cross.
Hypothesis: 1. Monohybrid cross—Predict that 75% of the tobacco seeds will sprout and that green 80% will be the dominant color. 2. Dihybrid cross---In corn purple color and smooth texture are dominant.
Monohybrid cross: 1. Cut a piece of paper towel to fit inside a petri dish. 2. Place the paper towel inside the petri dish and moisten with water. Started 3/1/2013.100 seeds. 3. Sprinkle all of the seeds onto the paper towel and then cover the petri dish. 4. Place seeds near a warm window with indirect light. 5. Observe seeds for germination each day and moisten the paper towel as needed. 6. Once the majority of seeds have germinated, remove the lid of the petri dish and count the number of seedlings that are green versus those that are yellow. Results noted on 3/10/2013.
Data Table 1: Punnet square
Father (CC) X Mother (cc) Father
Gametes C C
Mother c Cc Cc c Cc Cc
Data Table 2: Seedling data. | | Seedling Color | | | Green | Yellow | Total | Number ofSeedlings | 43 |