Inheritance of Genetic pattern

Inheritance patterns explain how traits are passed from parents to offspring. These patterns are governed by Mendelian and non-Mendelian principles.

Mendelian Inheritance

Overview:

• Based on Gregor Mendel’s experiments with pea plants.
• Involves traits controlled by single genes on autosomal chromosomes.

Key Laws:

1. Law of Segregation:

   • Each individual has two alleles per gene, one from each parent, which separate during gamete formation.

2. Law of Independent Assortment:

   • Alleles of different genes assort independently during gamete formation, creating various allele combinations.

Modes of Inheritance:

1. Autosomal Dominant:

   • A single dominant allele causes the trait.
   • Offspring have a 50

2. Autosomal Recessive:

   • Two recessive alleles are required to express the trait.
   • Offspring have a 25

3. X-Linked Dominant:

   • Affects the X chromosome.
   • Males have a 50

4. X-Linked Recessive:

   • More common in males (one X chromosome).
   • Females need two copies of the recessive allele to express the trait.

Non-Mendelian Inheritance

Overview:

• Involves complex genetic interactions that don’t follow Mendel’s laws.

Types:

1. Codominance:

   • Both alleles are equally expressed (e.g., AB blood type).

2. Incomplete Dominance:

   • Neither allele is dominant, resulting in a blended phenotype (e.g., red + white flowers = pink).

3. Polygenic Inheritance:

   • Multiple genes contribute to a single trait (e.g., skin color, height).

4. Epistasis:

   • One gene’s expression is affected by another gene.

5. Mitochondrial Inheritance:

   • Traits passed via maternal mitochondrial DNA.

6. Genomic Imprinting:

   • Gene expression varies based on whether the gene is inherited from the mother or father due to epigenetic modifications.

Thank you for reading from Firsthope's notes, don't forget to check YouTube videos!