PSYCH 1XX3 Lecture Notes - Lecture 4: Quantitative Trait Locus, Phenotypic Trait, Y Chromosome
18 Mar 2016
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Document Summary
Zygotes are new cells formed by a sperm and ovum comprising of 46 chromosomes. A chromosome is a threadlike structure made from dna segments of dna comprise genes which provide the chemical code for development. Our chromosomes contain between 30 000 to 40 000 genes. Zygotes divide exponenially to form billions of diferent cells with the same 46 chromosomes inherited at concepion. Parents can produce more than 8 million diferent geneic combinaions from their sperm or ova. Monozygoic twins share the same sperm and ovum and are geneically idenical. Dizygoic twins do not share the same sperm and ovum and therefore are as geneically idenical as siblings (50% of genes are shared) The 23rd set of chromosomes expresses the gender of the child (sry gene) Males determine the sex of the child by either contribuing an x chromosome (female) or a y chromosome (male)
