Question

What is the First law of Segregation?

Answer 1

Gregor Mendel established the fundamental rules of heredity through his research on pea plants. He determined that genes are inherited in pairs and as separate units, one from each parent. Mendel studied the segregation of parental genes and their manifestation as dominant or recessive characteristics in the offspring. He was aware of the mathematical patterns of heredity passed down from generation to generation.

Complete answer:
After noticing that pea plants with two distinct qualities produced offspring that all exhibited the dominant feature, while the following generation expressed the dominant and recessive traits in a $3:1$ ratio, Mendel developed the Law of Segregation.
According to Mendel's Law of Segregation, a diploid organism transfers a randomly selected allele for a characteristic to its offspring, with each parent receiving one allele. During meiosis, chromosomes split into distinct gametes, and each gamete receives one of the two alleles.
Both alleles are expressed in the $F2$ generation of a monohybrid cross without any mixing. The law of segregation is thus predicated on the fact that each gamete only has one allele. This rule is founded on four fundamental ideas:
There are many alleles for a single gene.
When meiosis produces gametes, the allelic pairings split apart, leaving each gamete with only one allele.
For each characteristic, each organism inherits two alleles.
A pair's two alleles are distinct, with one being dominant and the other recessive.

Note:
The first division of meiosis, in which homologous chromosomes with their various copies of each gene are separated into daughter nuclei, provides the physical basis of Mendel's law of segregation. The segregation of alleles at each genetic locus to distinct gametes can be explained by the activity of homologous chromosomes during meiosis.