HSCI 100 Lecture Notes - Lecture 7: Noncoding Dna, Allosome, Chromatin

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Ian Tietjen

Document Summary

Gene: entire nucleic acid sequence that is necessary for the synthesis of a functional polypeptide, dna regions that code for functional rna molecules, such as trna, rrna, mrna and are also considered genes. Human chromosomes: 23 pairs within a nucleus, pairs called homologous chromosomes, autosomes are 22 pairs of homologous chromosomes. Sex chromosomes (1 pair of x, y) contains genes that establish gender (xx female, xy male). Somatic cells (body cells) - 46 chromosomes called diploid (2n) that divide by mitosis: germ cells (sex cells) divide by meiosis and create gametes that only have 23 chromosomes and are not in pairs called haploid (n). Genotype -> phenotype: genotype is able to create a range of phenotypes (traits or adaptations) and phenotypes are further influenced by the enviro. Since we have 2 copies of each gene, individuals can have same or different alleles. Dominant allele - single copy of allele is sufficient to manifest the phenotype (ie. tt or tt)