Genetics Mendel Law ICSE Class 10 Biology Notes. covers the Mendel experiment on inheritance. Key concepts include Law of Mendel, Monohybrid and dihybrid cross and Mutation, Test and Back Cross. Understanding how traits are passed down from one generation to the next is crucial for grasping this chapter. Visit official Website CISCE for detail information about ICSE Board Class-10 Biology.
Genetics Mendel Law ICSE Class 10 Biology Notes Ch-3
Point to be discuss
- Mendel experiment on inheritance.
- Law of Mendel,
- Monohybrid and dihybrid cross a
- Test and Back Cross
- Mutation,
Mendel Experiment on Inheritance
established fundamental principles of inheritance, including the concept of dominant and recessive traits, and the segregation of traits during gamete formation. By meticulously documenting the traits of pea plants across multiple generations, he discovered that traits are passed down in a predictable manner.
Dominant and Recessive Traits:
Mendel observed that in the first generation (F1) of offspring from crosses between plants with contrasting traits, only one trait would be expressed. He termed this the dominant trait, while the other, which was hidden, was the recessive trait.
Segregation of Traits:
When F1 plants were allowed to self-pollinate, the hidden recessive trait reappeared in the second generation (F2) plants. This led Mendel to propose that each trait is determined by two “factors” (now known as genes), and these factors separate (segregate) during gamete formation, with each gamete carrying only one factor.
Law of Independent Assortment:
When Mendel crossed plants with two or more traits, he found that each trait was inherited independently of the others. This means that the inheritance of one trait does not influence the inheritance of another.
Monohybrid and Dihybrid Cross
In genetics, a monohybrid cross examines the inheritance of a single trait, while a dihybrid cross explores the inheritance of two traits. Monohybrid crosses typically result in a 3:1 phenotypic ratio in the F2 generation, whereas dihybrid crosses usually show a 9:3:3:1 ratio n the F2 generation,
3:1 Ratio:
In his experiments involving one trait, Mendel consistently observed a 3:1 ratio of dominant to recessive traits in the F2 generation. This ratio provided strong evidence for his proposed model of inheritance.
Test and Back Cross
a test cross involves breeding an individual with an unknown genotype (usually dominant phenotype) with a homozygous recessive individual to determine the genotype of the unknown parent. A backcross, on the other hand, is a cross between an F1 hybrid and one of its parent
Mutation
a mutation is a permanent and heritable change in the DNA sequence of an organism. These changes can occur at different levels, from a single nucleotide substitution to large-scale alterations of chromosomes, and can have a range of consequences for the organism.
- Sickle Cell Anemia
- Radioactive radiation
–: End of Genetics Mendel Law ICSE Class 10 Biology Notes. Mendel inheritance.,. :–
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