BIOL-3303 Study Guide - Final Guide: Single-Nucleotide Polymorphism, Rna Splicing, Foregut Fermentation
Document Summary
A larger genome does not mean more protein coding genes are present. Duplicates (paralogs) exist; one copy preserves function while the other may acquire a new function. Different products can form from one gene via alternative splicing. Fruit flies do not have many genes, but have highly regulated transcription genes to allow more cell types. The mrna may be produced more than once by our genes via alternative splicing. Huge genome size diversity within prokaryotes; larger prokaryote genomes contain more genes with less intergenic space. This difference in size correlates to environmental challenges. Archaebacteria have smaller genomes than eubacteria because they occupy a specialized environment and require little metabolic diversity. Larger prokaryote genomes have more gene duplications and acquisitions via horizontal transfer. Bacterial genomes do not continue to expand indefinitely because deletions are frequent in bacterial genomes. Roughly 40% of dna is shared between strains, but pathogenic strains have unique islands of acquired dna.
