- Use the permanent marker to label the two 100 mL beakers as "1" and "2".
- Pour 50 of the blue beads and 50 of the yellow beads into Beaker 1. Sift or stir the beads around to create a homogenous mixture.
- Pour 50 of the red beads and 50 of the green beads into Beaker 2. Sift or stir the beads around to create a homogenous mixture.
Assumptions for the remainder of the experiment:
- Beaker 1 contains beads that are either yellow or blue.
- Beaker 2 contains beads that are either green or red.
- Both beakers contain approximately the same number of each colored bead.
- These colors correspond to the following traits (remember that Y/y is for kernel color and S/s is for smooth/wrinkled):
1. Yellow (Y) vs. Blue (y)
2. Green (G) vs. Red (g).
Part 2: Monohybrid Cross
- Randomly (without looking) take two beads out of Beaker 1. This is the genotype of Individual #1. Record the genotype in Table 1. Do not put these beads back into the beaker.
Table 1: Parent Genotypes: Monohybrid Crosses
|
Generation
|
Genotype of Individual 1
|
Genotype of Individual 2
|
P
|
|
|
P1
|
|
|
P2
|
|
|
P3
|
|
|
P4
|
|
|
- Repeat Step 1 for Individual #2. These two genotypes represent the parents (generation P) for the next generation.
- Set up a Punnett square and determine the genotypes and phenotypes for this cross. Record your data in Table 2
- Repeat Step 3 four more times (for a total of five subsequent generations). Return the beads to their respective beakers when finished.
Table 2: Generation Data Produced by Monohybrid Crosses
|
Parents
|
Possible Offspring Genotypes
|
Possible Offspring Phenotypes
|
Genotype Ratio
|
Phenotype Ratio
|
P
|
|
|
|
|
P1
|
|
|
|
|
P2
|
|
|
|
|
P3
|
|
|
|
|
P4
|
|
|
|
|