Question

What is the law of independent assortment? Explain with an example?

Answer 1

Hint: The law of independent assortment determines the spontaneous inheritance of maternal and paternal origins of genes. As such, the parents' maternal and paternal chromosomes are "independently assorted," meaning the chromosomes do not have to end up in the same gamete from the same source.

Complete step by step answer:
The Law of Independent Assortment states that among sexually reproducing species, multiple genes and their alleles are inherited separately. Chromosomes are divided into several gametes during meiosis. Via the mechanism of crossing-over, genes bound to a chromosome will rearrange themselves. Each gene, thus, is separately inherited.
For instance, all maternal chromosomes can end up with one gamete, while another can have a combination of both maternal and paternal chromosomes. It also suggests that the genes on these chromosomes are sorted separately. In effect, a vast amount of variation is generated by the Rule of Independent Assortment based on multiple gene variations that have not previously existed.
In one scenario, genes cannot be spontaneously assorted altogether. This happens for genes that are related, or genes that share the same chromosome. The crossing-over mechanism during meiosis, however, guarantees that all these genes are rearranged. Homologous segments of maternal and paternal chromosomes may be shared during crossing-over. This means that even related genes are sorted separately.
During the meiosis process , individual assortment occurs. Meiosis is similar to mitosis, with gamete cells being the sole final product. Gamete cells are called haploid and have half the DNA of normal, diploid cells. This is an important component of sexual reproduction that causes two gamete cells to join together to form a diploid zygote, comprising all the DNA required to construct a new organism.
As a simple example , let us consider a fictional bunny rabbit population that has only two recognisable traits: the colour of the fur (black or white) and the colour of the eyes (green or red). The black fur rabbit (B) is dominant over white (b), while red (g) is dominant over the green eye rabbit (G).
Two hybrid rabbits are combined in this hypothetical case. What this means is that, with green eyes, all rabbits look dark, but they actually do have a heterozygous genotype. The genotype BbGg belongs to all rabbits. Both the people have the same combination of features in this population of 2 rabbits. They are all, in other words, black and green eyes.
Each rabbit would have to develop gametes before breeding. Not only are the alleles segregated during this process (the law of segregation), but each copy of each chromosome is randomly allocated to another gamete. This means that babies will inherit various variations of these traits regardless of the maternal phenotype (black with green eyes). For context, the bbgg genotype could be given to one infant, giving it white fur and red eyes. Alternatively, the genotype Bbgg could also be given to a baby rabbit, giving it black fur and red eyes. The rule of individual assortment is this.

Additional Information: After breeding two different pea plants with two distinct characteristics, Mendel established the Law of Individual Assortment; he bred plants with yellow, round peas with plants that had wrinkled green peas. Both the descendants had bright, round peas because bright and round were dominant over wrinkled and green.
Although, as his first generation was crossbred in a dihybrid cross with each other, in the second generation there was a lot of difference. Peas were no longer just yellow and round, or green and wrinkled; some were green and round, and some were wrinkled and yellow. In comparison, the offspring exhibited a 9:3:3:1 ratio of their characteristics. Nine were yellow and round, three were green and round, three were yellow and wrinkled, and one was green and wrinkled. And as hundreds of dihybrids were crossed, this ratio remained similar.
This happened because each of the parent plants only have one allele to their offspring and because yellow and round were dominant characteristics in some individual plants and masked the green and/or wrinkled characteristics.

Note: The Mendel experiment found that, regardless of the yellow or green peas alleles, the alleles for round or wrinkled peas were inherited because the plants were not either round and yellow or green and wrinkled. We now know that they live on multiple chromosomes, causing them to be mixed up during the meiosis process.