I Assignment No 1:BIO 301D: MC170404186Q1: What are the phenotypic and genotypic ratios inMendel Law of Independent assortment?Answer:                  Genotypeis the genetic makeup of an organism that include number of chromosomes, numberof genes, the sequence of genes or the inheritance pattern of an organism. Theyare expressed in a pair of letters, usually which are alleles. The alleles pairsgenotype is commonly expressed as RR (each letter representing one allele) as adominant trait, Rr as co-dominant or as recessive.

This example uses the letterR, but difference letters are used to describe different traits. They areactual fact just variables.Phenotype is the physical appearance of an organism. Like the height of anorganism.

The color of the skin or the color of eyes. The phenotype includesphysical characteristics behavior corres-ponding to such species, structures,organs, behaviors reflexes etc.Example: Let’s BB or Bb is the coding for black hair. BB/Bb is the genotype andthe black hair is the phenotype.According to Mendel Law ofindependent assortmentExamples: Dihybrid cross, true breeding plants for two traits. Forexample, a plant that had green pod color and yellow seed color wascross-pollinated with a plant that had yellow pod color and green seeds.The traits for green pod color (GG) and yellow seed color (YY) aredominanat. Yellow pod color (gg) and green seed color (yy) are recessive.

F1plants heterozygous GgYy.F1 plants                                                                                           True breeding                         True breeding yellow                              All greenpods          Green pods with          x          pods with green                     =                with yellow seedsYellow seeds                             seedsGGYY                                         ggyy                                                                   GgYy After observing the resuts of dihybrid cross, Mendel allowed all of the F1plants to self pollinate.He reffered to these offspring as F2 generation.Mendel noticed the 9:3:3:1 ratio.                                                  F1 GgYy                                                  GY   Gy   gY   gy   GY   GGYY   GGYy   GgYY   GgYy   Gy     GGYy   GGyy   GgYy   Ggyy   gY   GgYy   GgYy   ggYY   ggYy   gy   GgYy   Ggyy   ggYy   ggyy F1 GgYy                           9:3:3:1ratio.

                                Phenotypic ratio is 9:3:3:1.Genotypic ratio is 1/16 (GGYY)+2/16(Ggyy)+2/16(GgYy)+1/16(GGyy)+1/16(ggYY) + 4/16(GgYy)+2/16(ggyy)+2/16(ggYy)+ 1/16(ggyy).