HSCI 100 Lecture Notes - Lecture 17: Punnett Square, Noncoding Dna, Allosome

• School: Simon Fraser University
• Department: Health Sciences
• Course: HSCI 100
• Professor: Mark Lechner

Document Summary

Each human chromosome is a single linear dna molecule (double helix) with a string of nucleotides that spell out genes and other information. The total dna in all the chromosomes of an organism is its genome and a complete genome is nearly always found in every cell. The first human genome sequenced in 2003. Human genome consist of about 3 billion base pairs ( 2 x ( 10 x 1o^9e) bp) Equivalent to a 6 billion page book. Protein-coding regions only account for 2% of genome! About 50% is repetitive dna of truly unknown function. There are many polymorphisms: sites in dna that vary among individuals. The different versions or variants are called alleles. Obtaining dna sequence information is now relatively easy and cheap approx. A gene is the nucleic acid sequence that is necessary for the synthesis of a functional polypeptide. Dna regions that code for function rna molecules, such as trna, rrna, and mrna are also considered gens.