To verify the law of independent assortment.
The law of independent assortment is one of the fundamental principles of genetics formulated by Gregor Mendel, the father of modern genetics, in 1865. This law describes how different genes segregate or assort independently during the formation of gametes (sex cells). Mendel's work with pea plants led to the formulation of several laws, and the law of independent assortment is one of them.
The law of independent assortment states that the alleles (gene variants) for different traits segregate, or assort, into gametes independently. In other words, one trait's inheritance does not affect another trait's inheritance. This principle applies to genes located on different chromosomes or far apart on the same chromosome.
The process of independent assortment occurs during meiosis, the cell division process that produces gametes. During meiosis, homologous chromosomes (chromosomes that carry the same genes but may have different alleles) segregate randomly into different gametes. The random assortment of chromosomes during meiosis leads to a variety of possible combinations of alleles in the offspring.
The law of independent assortment is a key concept in understanding the inheritance of multiple traits simultaneously and helps explain the diversity observed in the offspring of sexually reproducing organisms. However, it's important to note that this law is not applicable when genes are closely linked on the same chromosome, as they tend to be inherited due to genetic linkage.
Here are examples to illustrate the Law of Independent Assortment:
1. Mendel's Dihybrid Cross:
2. Fruit Fly Eye Color and Wing Length:
3. Human Genetics - Hair Color and Height:
4. Plant Genetics - Flower Color and Leaf Shape:
Mendel's Dihybrid Cross involved considering two different traits controlled by two pairs of alleles. The traits he chose were seed color (yellow or green) and seed shape (round or wrinkled) in pea plants. Mendel conducted a series of experiments to understand how these traits were inherited.
In standard form, Mendel's Dihybrid Cross is represented as
Parental Generation (P):
First Filial Generation (F1):
Dihybrid Cross (F1 × F1):
Second Filial Generation (F2):
Fig. 1 Punnett square - Law of Independent assortment
Phenotypic Ratio in F2 Generation:
The phenotypic ratio among the offspring in the F2 generation, resulting from this dihybrid cross, is 9:3:3:1 (yellow round: yellow wrinkled: green round: green wrinkled). This ratio corresponds to the different combinations of alleles resulting from the independent assortment of genes.
Students learn about