Chromosomes occur in pairs, with a copy of a given gene on each chromosome. Egg and sperm merge to form a fertilized egg with the full chromosome number. The fertilized egg divides into new cells by mitosis , which maintains the full chromosome number. Proteins consist of a string of amino acids. A protein s properties are determined by its amino acid sequence.
Mutations alter the base code in an individual s genes and result in altered proteins.
If the mutation occurs in a sex cell, it is inheritable. Trait inheritance is due to the chromosomal theory of inheritance. Evolution is gradual. Evidence supporting the theory of evolution the Linnaean classification system Based on degree of shared characteristics. The degree of relatedness between two organisms is reflected in how late during embryonic development the two organisms remain similar.