Genetics Controlled Assessment

Question: Discuss about the Genetics Controlled Assessment? Answer: Here Mendel has crossed pure breeding green unripe pods with pure breeding yellow unripe pods. In F1 generation, plants were formed with green pods. If, green unripe gamete is denoted as Y and yellow unripe gamete is denoted as y, the cross will be: YY X yy Yy . F1 Therefore, in green pod is dominant character and yellow pod is recessive character In F2, Male Female Y y Y YY (green) Yy (green) y Yy (green) yy (yellow) Table 1: (Ewens 2012) Therefore, the genotypic ratio will be 1:2:1 and phenotypic ratio will be 3:1 Therefore, within 580 F2 plants, 75%, that is 435 will be green unripe pod and 145 (25%) will be yellow unripe pod plants. 2) Here, wildtype Red Poll gamete is denoted as R and white shorthorn gamete is denoted by r. In F1 generation, a new colored calves were developed, colored roan with a genotype of Rr. a) roan X roan Male Female R r R RR (Red) Rr (Roan) r Rr (Roan) Rr (white) Table 2: (Roff 2012) Therefore, phenotype will be, Red: Roan: White = 1:2:1 b) roan X white Male Female R r r Rr (Roan) rr (White) r Rr (Roan) rr (White) Table 3: (James 2012) Therefore, the phenotypic ratio will be, Roan: White = 1:1 c) roan X red Male Female R r R RR (Red) Rr (Roan) R RR (Red) Rr (Roan) Table 4: (James 2012) Therefore, the phenotypic ration of this cross will be, Roan: Red = 1:1 3) In this cross, homozygous mauve (dark blue) can be denoted as BB and homozygous sky blue can be denoted as bb(pale blue). In F1 generation, all birds obtained were cobalt (mid blue) and in F2, all three kinds of birds were obtained. This phenomenon is known as incomplete dominance. BB X bb Bb F1 Male Female B b B BB (mauve) Bb (cobalt) b Bb (cobalt) Bb (sky blue) (Table 5: Hill, Becker and Tigerstedt 2012) The above checkerboard shows how the incomplete dominance gives rise of three different kind of birds in the following proportion Mauve: Cobalt: Sky blue = 1:2:1 4) Grey seed coat = GG (dominant), white seed coat = gg (recessive) Tall = TT (dominant) , short = tt (recessive) a) Pure breeding tall white seeded plant (TTgg) X Pure breeding short grey seeded plant (ttGG) TtGg (Tall Grey seeded plant) b) If the F1 plants (TtGg) are self fertilized the F2 generation will develop following plants: Male Female TG Tg tG tg TG TTGG TTGg TtGG TtGg Tg TTGg TTgg TtGg Ttgg tG TtGG TtGg ttGG ttGg tg TtGg Ttgg ttGg ttgg (Table 6: Wright 2012) Therefore, the F2 generation will develop the plants in following ratio- Tall grey seeded: Tall white seeded: Short grey seeded: Short white seeded = 9:3:3:1 5) Mother has A blood group, child has O blood group. Therefore, father can have A, B or O blood group. AO (Mother) X BO (Father) = OO (Children) AO (Mother) X OO (Father) = OO (Children) AO (Mother) X AO (Father) = OO (Children) 6) Hemophilia is a X linked disorder and transmitted from a carrier or hemophilic mother and a hemophilic father. If father is hemophilic and mother is unaffected; XH = hemophilic XHY x XX XY, XHX Thus, all daughters will be carrier If father is unaffected and mother is carrier: XY x XHX XY, XX, XHY, XHX Thus, 25% son will be hemophilic, but no daughter will be hemophilic, 25% will be carrier If father is hemophilic and mother is carrier: XHY x XHX XY, XHXH, XHY, XHX Thus, 25% daughter will be carrier and other 25% will be hemophilic, whereas 25% son will be hemophilic. Therefore, if the mother is carrier and father is hemophilic, 50% daughter will have the chance to carry hemophilic gene (Hayward, Bosemark and Romagosa 2012). Reference List Ewens, W.J., 2012.Mathematical Population Genetics 1: Theoretical Introduction(Vol. 27). Springer Science Business Media. Hayward, M.D., Bosemark, N.O. and Romagosa, T. eds., 2012.Plant breeding: principles and prospects. Springer Science Business Media. Hill, J., Becker, H.C. and Tigerstedt, P.M., 2012.Quantitative and ecological aspects of plant breeding. Springer Science Business Media. James Jr, N. ed., 2012.Quantitative genetic variation. Elsevier. Roff, D., 2012.Evolutionary quantitative genetics. Springer Science Business Media. Wright, J., 2012.Introduction to forest genetics. Elsevier.