Biology 1001A Lecture Notes - Lecture 9: Single-Nucleotide Polymorphism, Alu Element, Retrotransposon
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Lecture 9-origin of variation: circular chromosomes exist in plant chloroplast and mitochondria, mitosis checkpoint = metaphase, cells in mitosis have 4 x c. Genomic variants: variants in genomes is what makes people differ from one another, ventor individual genome sequence showed 1. 2 million variants. 25% of variant bases are snps (single nucleotide polymorphism); 75% are cnv (copy. Is elements are never free floating; they are always moving around, cutting and pasting from gene to gene. Is elements are considered biological mutagens , since they are naturally found in the genome, and cause mutations. They are completely different from chemical mutagens (outside chemical sources which cause mutations in a sequence): retrotransposons move via rna; their mechanisms allows them to be wandering along the sequence. Intermediate filaments are structures which maintain the cell"s shape: helps dna divide in a very controlled way, mitosis checkpoint is another mechanism to ensure inheritance. In limited cases, dna polymerases make errors as they assemble new molecules.