Marble lab

Punnet squares in notebook along with All of the data.

Hypothesis: I believe that using the punnet square is the best way to predict the outcome of a genetic cross. Because it shows how the alleles are transferred from the parents to the offspring.

Questions:

2) According to your results in Part 1, how many diffrent kinds of offspring are possible when the homozygous parents(BB and bb) are crossed? Do the results you obtained using the marble model agree with the results shown by a Punnett square?

There is only one possible combination, and that is Bb. This is because both of the parents are homozygous, pure-bred, So one parent has BB alleles and the other one bb, Dominant and recessive. The offspring will be a carrier of the recessive trait, but will have the dominant  trait expressed. My punnet square, was for this situation, 100% accurate.

3) According to your results in Part 2, what percentage of offspring are likely to be homozygous when a homozygous parent (BB) and a heterozygous parent (Bb) are crossed? What percentage of offspring are likely to be heterozygous? Does the model agree with the results shown by a Punnett square?

When observing the results we got in part 2, the crossing of Heterozygous and Homozygous parents, I noticed that my punnet square was once again correct. The punnet square showed that there was a 50% chance of the offspring being heterozygous and a 50%  chance it will be Homozygous. In our data half was BB and half was Bb, with no bb. This showed that the more complex genotypes do not alter the accuracy of the punnet square.

Diffrent kinds of offspring are possible when two heterozygous parents (BbxBb) are crossed? What percentage of each type of offspring are likely to be produced? Does the model agree with the results of a Punnett square?

When two heterozygous parents are crossed, there are three possible outcomes that could happen. According to the Punnett Squares, if two heterozygous parents are crossed, the outcome would be as follows: 25% of the offspring would have the genotype of BB, 25% would be bb, and finally, 50% of the offspring would inherit exactly the same alleles for a trait as their parents, which is Bb. Once again the Punnet square matched my data. 

5) For Part 3, if you did 100 trails instead of 10 trails, would your results be closer to the results shown in a punnett square? Explain.

I think that the results would be further from the punnet square, because then there is more left to chance. With only 10 trials, there is little room for chance, but with 100 trials, many things can change. This is similar to mutation, where some genes are mutated because of the chance.

6) In a paragraph, explain how the marble model compares with a Punnett square. How are the two methods alike? How are they different?

The two methods are rather similar, in the way that both can be used to predict the probability of the offspring . However they do have some crucial differences. The punet square is mostly used for predicting possible outcomes of the genotype, the marble modes is basically a test for the punet square, showing that its reliable or not.