Inheritance Fundamentals
Inheritance is the genetic transmission of traits from parents to offspring. It involves the passing down of DNA, which carries instructions for development, growth, and functioning of organisms.
Mendelian Inheritance
Gregor Mendel's pea plant experiments formed the foundation of genetics. His laws of segregation and independent assortment explain trait inheritance patterns and the recombination of genes.
Non-Mendelian Complexity
Beyond Mendel, traits can show incomplete dominance, co-dominance, and polygenic inheritance. Epigenetics further introduces gene expression changes that don't alter the DNA sequence.
Genetic Variation Sources
Variation arises from mutations, genetic recombination during sexual reproduction, and lateral gene transfer. It's crucial for a population's adaptability and evolution.
Chromosomal Inheritance
Chromosomes, carriers of genes, follow a complex inheritance pattern. Errors during meiosis can lead to variations like trisomies, responsible for conditions such as Down syndrome.
DNA Mutations Impact
Mutations can be silent or cause notable changes. Beneficial mutations lead to evolution while deleterious ones can cause genetic disorders or be lethal for the organism.
Evolutionary Significance
Inheritance and variation are central to the theory of evolution. They enable natural selection to increase or decrease traits' frequency in a population over generations.