ANALYSIS (3 points each) Answer in complete sentences. What is meant by expected genotypes? the mathematical expectations for ea
ch genotype to occur based on a Punnett Square Are expected results due to chance or are they arrived mathematically? ? What is meant by observed genotypes? ? Are observed results due to chance or are they arrived mathematically? ? What does each side of each coin represent? ? How does the chance of a coin landing on each side compare to the chance that a gamete cell will receive a particular gene at meiosis? ? Why must two coins be used to determine the genotypes the offspring? ? What does the use of two coins compare to at fertilization? ? Compare the expected genotypes of 100 offspring with the observed genotypes.Do they agree or disagree? If they disagree, how much do they disagree? ? Are the results wrong if the results do not agree? Explain. ? What is the advantage of comparing the 100 expected offspring with the 100 observed offspring rather than comparing only four expected offspring with four observed offspring? ? Compare the expected phenotypes of 100 offspring with the observed phenotypes.Do they agree or disagree? If they disagree, how much do they disagree? ?
1 answer:
<u>Note</u>: Your question lacked the table for the 100 coin tosses resulting from such a practical laboratory. However, this affects only the last question (noted by me as 14). For that part I provided an answer based on my own experience with such an experiment. It should still be aplicable to yours.
Please find below the answer for each of your questions.
1. What is meant by expected genotypes?
The genotype or the genetic constitution of an organism is composed of sets of genes that determine an individual’s characteristics (phenotype).
2. The mathematical expectations for each genotype to occur based on a Punnett Square.
A Punnet Square is a visual representation of the resulting genotypes of a particular cross in the form of a square diagram.
Attached table image!!!
The mathematical probabilities are: BB 25%, Bb 50% and bb 25%.
3. Are expected results due to chance or are they arrived mathematically? ?
The expected results in the above square are conforming to a monohybrid cross phenotype ratio of 3:1, where three offspring will show the dominant trait (B) and one the recessive (b). All these expected results are obtained through mathematical calculations as shown above.
4. What is meant by observed genotypes? ?
The observed genotype is the actual genotype that can be observed from the results of the cross.
5. Are observed results due to chance or are they arrived mathematically? ?
The observed genotype results occur by change. However, they are usually strongly correlated with the mathematical model.
6. What does each side of each coin represent?
Each side of the coin represents one gene coming from one of the parents (B or b).
7. How does the chance of a coin landing on each side compare to the chance that a gamete cell will receive a particular gene at meiosis? ?
Conform to the theory of probability, there is a 50/50 chance that the coin will land on heads/tails, identical to that of a heterozygous parent with a dominant + recessive (B+b) gene.
8. Why must two coins be used to determine the genotypes the offspring? ?
As shown in the Punnet Square above, the offspring will inherit a genetic set from each parent. Thus, two coins (Bb + Bb) are required to represent what gene will come from each parent.
9. What does the use of two coins compare to at fertilization? ?
By using two coins, we mimic the chances of gene inheritance present in the fertilization process. We create a practical model of the “fertilization process” and its genetic results.
10. Compare the expected genotypes of 100 offspring with the observed genotypes.
11. Do they agree or disagree? If they disagree, how much do they disagree? ?
Generally, as stated above the practical results of such a coin experiment tend to closely follow the theoretical model.
12. Are the results wrong if the results do not agree? Explain.
The theory of probability is based on the assumption that the results of the coin toss are random. However, if there is a high deviation between the mathematical model and the practical results, then some unknown factor may affect the coin toss. Thus, it is no longer random and it no longer follows the random fertilization process. A new coin or person conducting the tosses should be used.
13. What is the advantage of comparing the 100 expected offspring with the 100 observed offspring rather than comparing only four expected offspring with four observed offspring?
In science, a large sample size is vital to all experiments. By comparing a large number of trials, chances of obtaining skewed results are minimized. Only four trial could give the appearance that a homozygous BB occurs significantly less/more than it should. This can occur due to chance. However, an increased number of trials provides a more realistic ratio between the observed and expected genotypes.
14. Compare the expected phenotypes of 100 offspring with the observed phenotypes.Do they agree or disagree? If they disagree, how much do they disagree? ?
Generally, in such experiments, the observed differences between the mathematical model and obtained results is around 1%. This is not considered a significant difference.
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