1. Genetic Inheritance:
* Parents: An organism inherits half of its genetic material (DNA) from its mother and half from its father.
* Chromosomes: DNA is organized into structures called chromosomes. Humans have 23 pairs of chromosomes, with one chromosome from each pair coming from the mother and the other from the father.
* Genes: Each chromosome contains thousands of genes, which are segments of DNA that code for specific traits.
* Alleles: Each gene exists in different versions called alleles. For example, a gene for eye color might have an allele for brown eyes and an allele for blue eyes.
* Combination of Alleles: The combination of alleles an organism receives from its parents determines its genotype for each trait.
2. Mutation:
* DNA Changes: Mutations are permanent alterations in the DNA sequence. These changes can occur spontaneously or be induced by environmental factors.
* New Alleles: Mutations can create new alleles, introducing new genetic variation into a population.
* Altered Genotypes: Mutations can directly alter an organism's genotype, leading to changes in the traits it expresses.
In Summary:
An organism's genotype is determined by the specific combination of alleles it inherits from its parents, as well as any mutations that may occur in its DNA. This combination of genetic factors ultimately influences the organism's observable traits, or phenotype.
