PCS 182 Lecture Notes - Lecture 4: Nucleic Acid Double Helix, Dna Replication, Prokaryote

• School: Ryerson University
• Department: Physics
• Course: PCS 182
• Professor: Margaret Buckby

Document Summary

Gene: short stretch of dna bases, provides instructions for building a protein, give you all your physical characteristics large bio-molecule. Genome: complete sequence of dna bases in an organism. Dna replication: double helix, strands unzip , each isolated strand accepts/attaches free bases floating in the cell (a t and c g, now (double helix) two copies of original dna helix, some errors may have occurred. Mutants: mutation = permanent change in dna, the organism is a mutant, most mutants die because dna is too messed up, but the way evolution happens is through mutation. Natural selection: if a variation (mutation) is beneficial, those progeny who inherit beneficial trait enjoy greater success, they dominate the population, thus, a species adapts and evolves over generations. Hypothesis: billions of years ago a bacterium is eaten/engulfed by another prokaryote, but remains viable and functions as an organelle/mitochondrion.