Introduction to Mendelian Genetics
Genetics is the branch of Biology that studies heredity. Gregor Mendel, regarded as the Father of Genetics, found that traits are inherited by passing on factors from parents. The Parent Generation (P1) refers to the parent plants, while the First Generation (F1) and Second Generation (F2) are the first and second generations (children and grand children) respectively. A gene is a segment of DNA located on the chromosomes that code for a trait, and an allele refers to different gene forms (such as tall or short). It is important to note that two alleles determine a trait, where the dominant trait is observed and represented by a capital letter.
Mendelian Genetics Summary
The law of segregation states that the two (sperm/egg) are formed, and parents pass on the dominant trait first. Additionally, the law of probability, also known as the "rule of chance," involves calculating the odds or chance of occurrence in genetics. The Punnett Square is a tool used to predict and compare the genetic variations resulting from a cross, such as the monohybrid cross for one trait. The terms true breeding, recessive, dominant, genotype, phenotype, heterozygous, and homozygous are also significant in understanding Mendelian genetics.
Mendelian Genetics Examples
An example of a monohybrid cross is provided, where purple flowers (dominant) are crossed with white flowers (recessive), along with a detailed explanation of the Punnett Square and the genotypic and phenotypic ratios. The text also explores the chances of getting a white plant in the F2 generation and a wrinkled seed plant based on specific crosses and genetic combinations.
Law of Independent Assortment
The second day's notes focus on the law of independent assortment, where alleles can recombine in four different ways to form gametes. The concept of dihybrid cross for two characteristics/traits and the understanding of how genes for different traits are inherited are explained. Various examples, including genotypic and phenotypic ratios, and an overview of dihybrid crosses, are also covered in this segment.
Non-Mendelian Genetics
This section introduces the concept of incomplete dominance and co-dominance, providing examples of how certain traits are expressed when alleles are not completely dominant or when both alleles are equally dominant. It also discusses how multiple alleles can exist in a population, using ABO blood type (multiple alleles; co-dominance) as an example. Furthermore, the text delves into polygenic inheritance, where more than one gene determines the trait and factors other than genotype also affect phenotype.
Sex Linked Inheritance
The final day's notes focus on sex-linked inheritance, delving into X-linked dominant and X-linked recessive inheritance patterns and providing examples of traits such as hemophilia and red/green color blindness. The text also touches upon pedigrees and how they are used to study inheritance patterns within families.
In conclusion, these notes provide a comprehensive overview of Mendelian and non-Mendelian genetics, covering key concepts, examples, and inheritance patterns. For further in-depth study, additional resources such as Mendelian genetics PDF, Mendelian genetics PPT, and Mendelian genetics Khan Academy can be explored.
