Genetics<\/p>\n
The controlled matting of organisms allowed for the basic patterns of inheritance to be deduced. Understanding patterns of inheritance was instrumental in developing the study of genetics and has grown from typing of physical traits (Phenotyping) to very complex molecular analysis of DNA. <\/p>\n
Controlled matting experiments are highly dependent on the organism being studied. A simple cross using the nematode C. elegans can be performed in less than a week, while fruit files need months and corn requires 6-9 months! <\/p>\n
Based on Mendel\u2019s laws of inheritance, fairly complex genetic problem can be investigated with computer simulation to allow genetic experiments to be performed during a normal class period rather than months. <\/p>\n
In this exercise you will use StarGenetics to simulate mating experiments with pea plants. The purpose is to analyze the nature and mode of the inheritance of specific genetic traits. Additionally, inferring genotypes from phenotypes will be investigated. <\/p>\n
The genetics simulator we will use is found at https:\/\/star-genetics.surge.sh\/ and should work in both Firefox and chrome<\/p>\n
Watch the video on how to work with the simulator before doing the following. <\/p>\n
Mendel\u2019s Peas Exercise 1 Part 1<\/p>\n
Start simulation<\/p>\n
Navigate to https:\/\/star-genetics.surge.sh\/<\/p>\n
From the pulldown menu select \u201cMendel\u2019s Peas Exercise 1 Part 1\u201d<\/p>\n
Which stock plants are pure breeding?<\/p>\n
Identify which stock strains are pure breeding by performing a self-cross with each plant. <\/p>\n
Pure breeding strains are ones that when self-crossed will produce the same phenotype in the next generation and only that phenotype.<\/p>\n
You can self-cross each plant by selecting the plant twice to the matting site<\/p>\n
Generate at least 80 progeny.<\/p>\n
Record your observation and if it is pure breeding. <\/p>\n
Strain Stock<\/p>\n
Observed phenotype(s) and percentages<\/p>\n
Is it pure breeding? <\/p>\n
White parent<\/p>\n
100%<\/p>\n
Phenotypes: Unisex, it\u2019s tall and white, pod color is green, pod shape inflated, and pea color is smooth and green.<\/p>\n
Yes, it has the same phenotypes as it\u2019s parents.<\/p>\n
Purple Parent 1<\/p>\n
100% <\/p>\n
Phenotypes: Unisex, it\u2019s tall and purple, green pod color, inflated pod shape, green pea color and smooth.<\/p>\n
Yes it has the same phenotype as it\u2019s parents.<\/p>\n
Purple Parent 2<\/p>\n
It is 24% the white plant and 76% the of the purple parent 2. At total of 19 white peas, and 61 purple parent 2 peas. <\/p>\n
Phenotypes: there is a mix <\/p>\n
White plant:<\/p>\n
Unisex, it\u2019s tall and white, pod color is green, pod shape inflated, and pea color is smooth and green.<\/p>\n
Purple plant 2:<\/p>\n
Unisex, it\u2019s tall and purple, green pod color, inflated pod shape, green pea color and smooth.<\/p>\n
No, it has a mixed gene or Aelle from the white plant, and the purple plant 2.<\/p>\n
Which phenotype is dominate?<\/p>\n
Determine the dominate phenotype by crossing White Parent with Purple Parent 1 and report the phenotype(s) of the F1<\/p>\n
Observed Phenotype(s)<\/p>\n
Number of individuals<\/p>\n
What is the dominate phenotype?<\/p>\n
unisex, tall, purple, axial pod position. inflated pod shape and inflated, green pea color, and smooth.<\/p>\n
2 parent indiviauls. <\/p>\n
And 1 indivual made from the two.<\/p>\n
The purple parent 1 has the dominant phenotype.<\/p>\n
What are the genotypes?<\/p>\n
Based on the results you have collected so far what genotypes would you predict for the listed plants?<\/p>\n
Phenotypes<\/p>\n
Probable Genotypes <\/p>\n
White Parent<\/p>\n
Tall, White, recessive, green pea color, and smooth. <\/p>\n
pp <\/p>\n
Purple Parent 1<\/p>\n
Tall, purple, green pea color, and smooth.<\/p>\n
PP<\/p>\n
F1 progeny <\/p>\n
Tall, purple, green pea color, and smooth.<\/p>\n
PP <\/p>\n
Prediction of F2 Results<\/p>\n
Based on the probable genotypes you recorded in the table above, what phenotype ratio would you predict for the F2 generation if you cross two F1 plants?<\/p>\n
https:\/\/www.omnicalculator.com\/health\/punnett-square is a useful online Punnett square app. <\/p>\n
Predicted phenotype ratio of the F2 if two F1s are crossed<\/p>\n
3:1 ratio.<\/p>\n
What are the F2 phenotypes?<\/p>\n
Cross two F1 plants and report the phenotypes, number of plants and phenotype ratio<\/p>\n
Observed Phenotype(s)<\/p>\n
Number of individuals<\/p>\n
Observed %<\/p>\n
PP and PP <\/p>\n
The gene of the plant is <\/p>\n
1 classes: total is 80<\/p>\n
PP Dominant, so the plant will be purple, and like its parent gene.<\/p>\n
Observed F2 ratio (dominate : recessive)<\/p>\n
Did you observe the ratio you predicted?<\/p>\n
100% it is (dominate: dominate) <\/p>\n
Yes, but the ratio is a lot further than the what was shown above.<\/p>\n
If you did not observe the ratio you predicted, use the +more Progeny button to increase the sample size. Or if you are curious about changing the sample size, add more plants to the cross. <\/p>\n
Record your updated information.<\/p>\n
Observed Phenotype(s)<\/p>\n
Number of individuals<\/p>\n
Observed %<\/p>\n
Dominaint <\/p>\n
1 class : 160 total<\/p>\n
Updated F2 ratio (dominate : recessive)<\/p>\n
Did you observe the ratio you predicted after adding more plants?<\/p>\n
Why might your ratios vary between your initial data and the data from additional mattings vary?<\/p>\n
Explanation of sample size issues<\/p>\n
Based on the information collected what are the possible Genotypes for the F2 plants?<\/p>\n
Phenotypes<\/p>\n
Probable Genotypes <\/p>\n
Test Cross<\/p>\n
Dominate phenotypes can have multiple possible Genotypes. For example, Aa and AA will have the same phenotype as only one dominate allele is needed to express the phenotype. <\/p>\n
In contract, a recessive phenotype must be aa! <\/p>\n
A method to determine the genotype is to perform a test cross. This is where a plant with a dominate phenotype is crossed with a recessive one. <\/p>\n
There are two possible outcomes in such a situation. Fill in the resulting genotypes for each Punnett square<\/p>\n
Recessive plant<\/p>\n
Recessive plant<\/p>\n
Dominate<\/p>\n
a<\/p>\n
a<\/p>\n
Dominate<\/p>\n
a<\/p>\n
a<\/p>\n
A<\/p>\n
Aa<\/p>\n
Aa<\/p>\n
A<\/p>\n
Aa<\/p>\n
Aa<\/p>\n
A<\/p>\n
Aa<\/p>\n
Aa<\/p>\n
a<\/p>\n
aa<\/p>\n
aa<\/p>\n
Possible Genotypes that produce dominate phenotype<\/p>\n
Possible phenotype ratio resulting from test cross <\/p>\n
AA, Aa<\/p>\n
50:50 (1 to 1 ratio)<\/p>\n
You will use the process of the test cross to identify the genotype of several dominate pea plants. Use the predictions you made above on who the test cross will work to make a conclusion about the plant\u2019s genotypes. <\/p>\n
Mendel\u2019s Peas Exercise 1 \u2013 Part 2<\/p>\n
From the pull-down menu, change the experiment to \u201cMendel\u2019s Peas Exercise 1 \u2013 Part 2\u201d <\/p>\n
There are several plants in the strain stock region. Perform a test cross to determine the genotype of each purple plant. <\/p>\n
Plant<\/p>\n
Observed phenotype ratio when crossed with White plant<\/p>\n
Genotype of Purple plant <\/p>\n
Purple F2-A<\/p>\n
Class 1 total – white: 35 (44%)<\/p>\n
Class 2 total- purple: 45 (56%)<\/p>\n
Ratio: 1:3 to 1<\/p>\n
Pp <\/p>\n
Purple F2-B<\/p>\n
Class 1 total \u2013 purple:46 (58%)<\/p>\n
Class 2 total \u2013 white: 34 (43%)<\/p>\n
Ratio: 1:1 <\/p>\n
Pp or pp<\/p>\n
Purple F2-C<\/p>\n
Class 1 total \u2013 purple: 80 (100%)<\/p>\n
Ratio: 1:3 ratio<\/p>\n
Pp<\/p>\n
Purple F2-D<\/p>\n
Class 1 total \u2013 purple: 29 (36%)<\/p>\n
Class 2 total \u2013 white: 51 (64%)<\/p>\n
Ratio: 1:1<\/p>\n
Pp or pp<\/p>\n
Purple F2-E<\/p>\n
Class 1 total \u2013 purple: 80 (100%)<\/p>\n
Ratio:<\/p>\n
Pp<\/p>\n
Purple F2-F<\/p>\n
Class 1 total \u2013 purple: <\/p>\n
Class 2 total \u2013 white: <\/p>\n
Ratio:<\/p>\n
Purple F2-G<\/p>\n
Class 1 total \u2013 purple: <\/p>\n
Class 2 total \u2013 white: <\/p>\n
Ratio:<\/p>\n
Purple F2-H<\/p>\n
Class 1 total \u2013 purple: <\/p>\n
Class 2 total \u2013 white: <\/p>\n
Ratio:<\/p>\n
Purple F2-I<\/p>\n
Class 1 total \u2013 purple: <\/p>\n
Class 2 total \u2013 white: <\/p>\n
Ratio:<\/p>\n
Purple F2-J<\/p>\n
Class 1 total \u2013 purple: <\/p>\n
Class 2 total \u2013 white: <\/p>\n
Ratio:<\/p>\n
Dihybrid Crosses <\/p>\n
Mendel proposed the law of independent assortment where different traits do not affect the inheritance of each other. Be aware that examining two traits at once generates a more complex set of phenotype classes due to the possible combinations that can occur.<\/p>\n
You will examine two traits, Pea color and Pea shape. The simulator tracks several traits but for this activity you\u2019ll focus on just these two.<\/p>\n
Rough Yellow Pea<\/p>\n
Rough Yellow Pea<\/p>\n
Plant B has rough yellow peas, and you can observe this in the image or by using the \u201cshow Phenotypes\u201d button to see a list of the phenotypes. But remember it will also show you phenotypes for other traits that we are not interested in. <\/p>\n
NOTE: IGNORE the pod color, pod shape, and flower color.<\/p>\n
Parental Cross<\/p>\n
From the pull-down menu select \u201cMendel\u2019s Peas Guided Exercise\u201d<\/p>\n
Mate Plant A with Plant B<\/p>\n
What observations can you make about the F1 progeny from this cross? <\/p>\n
The pea shape of class 1 is inflated and smooth. The pod is green, and the height is tall. <\/p>\n
The pease shape of class 2 is inflated and smooth. The pod is yellow, and the height is tall.<\/p>\n
What phenotype is dominate for Seed Color and for Seed Shape? <\/p>\n
The dominate seed color is green and the seed shape is smooth and inflated.<\/p>\n
Based on these results what genotypes would you predict for Plant A and Plant B?<\/p>\n
Recall that you need different symbols for the two traits. <\/p>\n
Plant<\/p>\n
Probable Genotype for Seed Color<\/p>\n
Probable Genotype for Seed shape<\/p>\n
Plant A<\/p>\n
Plant B<\/p>\n
Based on your above results and your predictions for the parental Plant A and B, what genotype do you predict for the F1?<\/p>\n
Plant<\/p>\n
Probable Genotype for Seed Color<\/p>\n
Probable Genotype for Seed shape<\/p>\n
F1<\/p>\n
Cross F1 to Generate F2<\/p>\n
What Phenotype ratio would you predict for the F2 based on the F1 Probable Genotypes?<\/p>\n
https:\/\/www.omnicalculator.com\/health\/punnett-square<\/p>\n
Select an F1 plant and perform a self-cross with at least 200 progeny.<\/p>\n
Examine ONLY the pea color and pea shape. And report the results in the table.<\/p>\n
NOTE: You may have to use the green arrows to see all the plants. <\/p>\n
NOTE: The simulator will have organized results based on ALL of the traits, so you will have to add together classes of phenotypes. See example below.<\/p>\n
Phenotype observed for Pea Color and Shape<\/p>\n
Number of individuals<\/p>\n
Example data collection: Class 2 and Class 3 are both round and yellow seeds, so they are the same phenotype at the traits we are measuring. You would add the number of individuals in each class together (10+21) = 31 have round yellow seeds in this example. <\/p>\n
What phenotype ratio did you observe? <\/p>\n
Does it agree with your prediction? Why or why not? What might you do if the ratio is \u201cclose\u201d to the prediction? <\/p>\n
Complete the table below, remember some phenotypes will have multiple genotypes. <\/p>\n
Phenotype observed for Seed Color and shape<\/p>\n
Possible Genotypes for each phenotype<\/p>\n
Explain at least two ways the genotypes predicted for each phenotype can be determined <\/p>\n
BONUS Questions:<\/p>\n
Bonus Problem<\/p>\n
Determine the Genotypes for Plant A and Plant B at the Pod Color and pod shape traits.<\/p>\n
Pant<\/p>\n
Genotype for Pod Color (Green\/Yellow)<\/p>\n
Genotype for Pod Shape (Inflated\/wrinkled)<\/p>\n
Plant A<\/p>\n
Plant B<\/p>\n
Explain how you determined the genotypes.<\/p>\n","protected":false},"excerpt":{"rendered":"
Genetics The controlled matting of organisms allowed for the basic patterns of inheritance to be deduced. Understanding patterns of inheritance was instrumental in developing the study of genetics and has grown from typing of physical traits (Phenotyping) to very complex molecular analysis of DNA. Controlled matting experiments are highly dependent on the organism being studied. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[10],"class_list":["post-79047","post","type-post","status-publish","format-standard","hentry","category-research-paper-writing","tag-writing"],"_links":{"self":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/79047","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/comments?post=79047"}],"version-history":[{"count":0,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/posts\/79047\/revisions"}],"wp:attachment":[{"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/media?parent=79047"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/categories?post=79047"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/papersspot.com\/blog\/wp-json\/wp\/v2\/tags?post=79047"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}