The Genome Allows for Genetic Diversity within Species
Definition
Genome
The genome is the complete set of genetic instructions that determines the structure, function, and traits of an organism.
- The genome is the instruction manual for building and maintaining an organism, written in the four DNA bases A, T, C, and G.
- It includes:
- Coding DNA: Sequences that encode proteins.
- Non-coding DNA: Sequences that regulate gene expression or have other functions.
- Think of the genome as a comprehensive instruction manual where:
- Chapters = Chromosomes, long strands of DNA wrapped around proteins.
- Sentences = Genes, specific sequences coding for proteins.
- Spaces = Non-coding regions, essential for timing and regulation.
Unity Within a Species
- All members of a species share the same set of genes arranged in the same order on their chromosomes.
- This shared structure ensures that organisms can reproduce successfully, allowing homologous chromosomes to pair, align and cross over correctly during meiosis.
All humans have the hemoglobin gene on chromosome 11, regardless of which allele version they inherit.
TipUnderstand that if the chromosomes don't pair correctly, sexual reproduction would fail.
Genetic Diversity within a Species
While genomes are largely uniform within a species, small variations exist, creating individual uniqueness.
Single-Nucleotide Polymorphisms (SNPs)
Definition
Single-Nucleotide Polymorphism (SNP)
SNPs are single base-pair changes in the DNA sequence.
- The most common source of variation is the single-nucleotide polymorphism (SNP).
