can i know the discussion for this experiment. it quite confusing


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27.50

can i know the discussion for this experiment. it quite confusing ATTACHMENT PREVIEW Download attachment lab report 3.docx SHES 2240 : GENETICS PRACTICAL 3 GENETICS OF CORN (ZEA MAYS) NAME : SITI NOR FATHIHAH BINTI MUHADZIR MATRIC NUMBER : SEF 120030 LECTURE’S NAME : DR. SYARIFAH AISYAFAZNIM BT SAYED ABDUL RAHMAN 1.0 INTRODUCTION Ears of corn are good study systems for learning about genetics, because each kernel represents an independent union of gametes, and thus a cob has a population of genetically unique kernels. The cobs you will be studying are variable for two traits of interest, color and sugar content. You can detect sugar content differences because high sugar kernels are wrinkled and low-sugar kernels are smooth. Each of these characteristics is determined by a single gene, with two alleles. There are four kernel phenotypes in the above ear of corn: Purple & Smooth (A) Purple & Wrinkled (B) Yellow & Smooth (C) Yellow & Wrinkled (D) An ear of corn is actually a collection of over a hundred offspring, neatly packaged onto a cob, able to be stored long term, perfect for studying genetics. Each corn kernel (seed) has a dormant embryo and an enhanced nutritive layer known as the endosperm, which will support the growing embryo until it germinates and can begin providing for itself via photosynthesis. Many genes determine the phenotypes of the 3 tissues that control the color of a corn kernel. These tissues are the pericarp, the aleurone (outer layer of the endosperm), and the endosperm proper. In our corn, the pericarp is always colorless, but the aleurone may be colorless, purple, or red, and the endosperm yellow or white. If the aleurone is colorless, the kernel color will be that of the endosperm, either yellow or white. Normal corn endosperm color (yellow) occurs when the allele Y causes the production of carotenoid pigments in the endosperm. In the recessive condition (y/y) carotenoids are not produced and the endosperm is white. The Y alleles are masked by the presence of a colored aleurone. For the aleurone to be colored, alleles C and R must be present. The homozygous recessive of either allele (c/c or r/r) disrupts anthocyanin production and results in a colorless aleurone. The dominant CI allele also inhibits anthocyanin production, giving a colorless aleurone. Genes C and R are located on separate chromosomes and segregate independently. The allele Pr interacts with alleles C and R to produce a purple aleurone. The homozygous recessive condition (pr/pr) interacts with C and R to produce a red aleurone. 1.2 MATERIAL A. Monohybrid and Dihybrid cross Corn with the following ear number: 9, 8900, 10, 8910, 12, 5, 4, 8915, 1 B. Complementary gene action Corn with the following ear number: 6, 3, 7, 8, 8920 1.3 METHOD 1. The samples were observed. 2. The number of kernels are calculated and chi-square test is used to test the goodness of fit between the observed results and expected results. 1.4 RESULTS Monohybrid Crosses (a) Ear number 9 Let W be the allele for red-coloured kernel, w be the allele for white-coloured kernel. Parental phenotype: Red White Parental genotype: WW Ww F1 genotype: All Ww F1 genotype: Ww Ww (meiosis) Gametes: W w W W (fertilisation) W WW Ww W w F2 genotypic ratio: 1 WW: F2 phenotypic ratio: W Ww Ww 2 Ww: 3 Red: 1 ww 1 White H0: The mode of segregation follows Mendel’s law. H1: The mode of segregation does not follow Mendel’s law. Phenotypic Class Observed Number (O) Expected Number (E) Red 221 414 White 331 138 2 χ (O−E)2 χ =⅀ E at P = χ 2 89.9734 269.9203 (O−E)2 E 2 0.05 359.894 Since law. 2 2 at P = 0.01 3.841 6.635 χ calculated > χ tabulated , H0 is rejected. The mode of segregation does not follow Mendel’s (b) Ear number 8900 Let W be the allele for purple-coloured kernel, w be the allele for white-coloured kernel. Parental phenotype: Purple White Parental genotype: WW Ww F1 genotype: All Ww F1 genotype: Ww Ww (meiosis) Gametes: W w W W (fertilisation) W WW Ww W w F2

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27.50