A. Title

Simulation of Mendel's Law Experiment Using Genetic Buttons in Monohybrid and Dihybrid Crosses

B. Objectives of the Practical Work

1. Define the terms gene, locus, genotype, phenotype, genome, dominant, and recessive.

2. Making crosses with one different trait (monohybrid)

3. Making a cross with two different traits (dihybrid)

C. Tools and Materials

1) Lab Coat Pocket

2) Genetic Button (Gene Model)

D. Work Procedures

a). Monohybrid

b). Dihybrid

E. Observation Results

1.  Monohybrid

2. Dihybrid

 

F. Discussion Results

1. Monohybrid Cross

      Monohybrid crossing is a crossing of two individuals with a focus on two different traits. In this experiment, we conducted a monohybrid crossing using genetic buttons (gene models) by crossing red flowers and blue flowers in order to prove Mendel's first law. Red flowers (MM) are dominant, symbolized by the red genetic button, and white flowers (mm) are recessive, symbolized by the white genetic button. Crossing between red buttons (MM) and white buttons (mm) resulted in F1 which was red (Mm) because the red button was dominant. F1 was crossed with each other, three types of phenotypes were obtained, namely red-red, red-white, and white-white. With genotypes for red (MM), red-white (Mm), and white-white (mm). According to Mendel's law of comparison, the phenotype ratio for monohybrid crossing is 3: 1. Based on the results of the experiments we conducted, for taking 8x the data obtained were for red as much as 2x, red-white as much as 4x, and for white as much as 2x. so that a ratio of 2:4:2 is obtained which is close to the ratio of 1:1:1 or 2:1. These results do not match the results of Mendel's experiments and are a deviation from Mendel's first law. These deviations are only apparent deviations due to the influence of the dominance of a trait, in this case the color red. From the results of the chis-square calculations that we did, we got the results of the monohybrid cross there was no difference (Ho) because Ho was acceptable, based on the value of the calculation table, the value was smaller than the chi-square, which was 1.1, while from the chi-square table it was 3.84. 

2. Dihybrid Crossing

      Dihybrid crossing is a crossing of two different traits. In dihybrid crossing we try to cross two different traits, namely color and shape. Where the colors are Red and Yellow, while the shapes are round and oval. In dihybrid crossing, the red genetic button is red, the yellow genetic button remains yellow, the green genetic button is round while the black genetic button is oval in shape with the intention of proving Mendel's second law experiment with a ratio of 9: 3: 3: 1. In this experiment, the phenotypes produced after the crossing were red-round, red-oval, yellow-round, and yellow-oval. With a genotype ratio of 16: 6: 10: 15 or 3: 1: 2: 3. The results obtained are not in accordance with Mendel's second law. It is possible to get the right results if you do the experiment several times. The results of the dihybrid cross that we conducted obtained the results of the dihybrid cross, there was a difference (H1), because H1 cannot be accepted, because based on the calculation table the value of 45.6 is greater than the chi-square of 7.82.

DOCUMENTATION

Monohybrid Genetic Buttons

Dihybrid Genetic Buttons

 

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