In science class we did an experiment in which we pulled marbles out of a bag to model the probability that a punnet square shows.
1.) Use a punnet square to gather statistics for the possible traits of offsprings from 2 homozygous parents (one dominant and one recessive) one homozygous dominant and one heterozygous parent and two heterozygous parents. Then compare the results to your hypothesis and lab results.
To see posible genotypes and phenotypes of offspring you use a Punnet square to cross the traits. When two homozygous parents (one for the dominant trait and the other for the recessive) the offspring are 100% heterozygous (meaning that the gene for the dominant trait shows, but they still carry the recessive alelle). When crossing one homozygous dominant parent with a heterozygous one, you get 50% heterozygous, and 50% homozygous dominant. Then, when crossing two heterozygous parents you get 50% heterozygous, 25% dominant homozygous, and 25% recessive homozygous offspring. These statistics closely resembled both my hypothesis for the experiment and the results I got.
2.) What are the possible genotypes of the offspring of one homozygous dominant and one homozygous recessive parent.
When crossing two homozygous parents, one for the dominant trait and one for the recessive, each parent can only pass on one type of alelle to their offspring. The dominant parent can only pass on the dominant gene and the recessive parent can only pass down the recessive gene. This means the only possible genotype for the offspring are the dominant trait and the recessive trait (example: Bb).
3.) Compare the ratio of heterozygous to homozygous offspring (both parents are heterozygous) and then compare it to your lab results.
In a cross with two heterozygous parents, it is 50% to 50% homozygous to heterozygous. We got about the same results in our testing and it matched my hypothesis.
4.) What is the genotypic ratio of the offspring of two heterozygous parents?
3:1(phenotype) three show dominant gene while one shows the recessive gene. 2:1:1 (genotypes in the order of heterozygous, homozygous dominant, and homozygous recessive).
5.) If there were 100 offsprings of two heterozygous parents, how many would have each genotype?
There would be 50 heterozygous offspring, 25 homozygous recessive offspring, and 25 homozygous dominant offsprings in total. This is just a guess since i did not take into account the probability and randomness of passing down genes.
6.) Write a paragraph comparing the model of taking marbles out of a bag (probability) and the exact estimations of the punnet squares.
For this lab we used marbles in bags to demonstrate the probability of Punnet squares. The punnet square only displays possibilities, while the marbles put the probability into action; consequently this causes you randomly select traits demonstrating both the probability and possibility of a real life situation. The punnet square shows the exact chances the offspring have of getting a trait, but it cannot compensate the randomness of a real situation. Overall the punnet squares show the statistics surrounding an offspring's possible genotypes, while the marbles showed what happens in real life situations.
Test 1: two homozygous (one dominant, the other recessive) parents. Test 2: one homozygous (dominant) parent and one heterozygous parent. Test 3: Two heterozygous parents.
1.) Use a punnet square to gather statistics for the possible traits of offsprings from 2 homozygous parents (one dominant and one recessive) one homozygous dominant and one heterozygous parent and two heterozygous parents. Then compare the results to your hypothesis and lab results.
To see posible genotypes and phenotypes of offspring you use a Punnet square to cross the traits. When two homozygous parents (one for the dominant trait and the other for the recessive) the offspring are 100% heterozygous (meaning that the gene for the dominant trait shows, but they still carry the recessive alelle). When crossing one homozygous dominant parent with a heterozygous one, you get 50% heterozygous, and 50% homozygous dominant. Then, when crossing two heterozygous parents you get 50% heterozygous, 25% dominant homozygous, and 25% recessive homozygous offspring. These statistics closely resembled both my hypothesis for the experiment and the results I got.
2.) What are the possible genotypes of the offspring of one homozygous dominant and one homozygous recessive parent.
When crossing two homozygous parents, one for the dominant trait and one for the recessive, each parent can only pass on one type of alelle to their offspring. The dominant parent can only pass on the dominant gene and the recessive parent can only pass down the recessive gene. This means the only possible genotype for the offspring are the dominant trait and the recessive trait (example: Bb).
3.) Compare the ratio of heterozygous to homozygous offspring (both parents are heterozygous) and then compare it to your lab results.
In a cross with two heterozygous parents, it is 50% to 50% homozygous to heterozygous. We got about the same results in our testing and it matched my hypothesis.
4.) What is the genotypic ratio of the offspring of two heterozygous parents?
3:1(phenotype) three show dominant gene while one shows the recessive gene. 2:1:1 (genotypes in the order of heterozygous, homozygous dominant, and homozygous recessive).
5.) If there were 100 offsprings of two heterozygous parents, how many would have each genotype?
There would be 50 heterozygous offspring, 25 homozygous recessive offspring, and 25 homozygous dominant offsprings in total. This is just a guess since i did not take into account the probability and randomness of passing down genes.
6.) Write a paragraph comparing the model of taking marbles out of a bag (probability) and the exact estimations of the punnet squares.
For this lab we used marbles in bags to demonstrate the probability of Punnet squares. The punnet square only displays possibilities, while the marbles put the probability into action; consequently this causes you randomly select traits demonstrating both the probability and possibility of a real life situation. The punnet square shows the exact chances the offspring have of getting a trait, but it cannot compensate the randomness of a real situation. Overall the punnet squares show the statistics surrounding an offspring's possible genotypes, while the marbles showed what happens in real life situations.
 | |||
| The test results from the making the right call lab. |
No comments:
Post a Comment