he chromosome complement of the mature pea plant is called , whereas the complement of the gametophytes and gametes is called .
In the sporophyte (diploid, 14 chromosomes) pea plant, after mitosis, each of the two daughter cells have chromosomes.
After meiosis (both divisions) in the sporophyte plant, each of the four daughter cells have chromosomes.
During the first meiosis division (M1), the pair and crossing-over (genetic exchange) occurs between their non-sister chromatids. The spindle then moves them to opposite sides of the cell, which results in a set of chromosomes in each daughter cell. Because it reduces the chromosome sets from to haploid, the M1 division is called the "reductional" division of meiosis.
The daughters of M1 each receive only one of each chromosome - also only one gene - for each pair of chromosomes - or genes - in the parent cell, not both. This demonstrates Mendel's law of .
During M1, when one homologue segregates into a daughter cell, it does not influence which of the two homologues for the other homologous chromosome pairs also segregates into that daughter cell. That means, that for different traits, inheriting a particular allele for one trait (like the yellow allele for pea color), does not influence whether a particular allele for a different trait (like round R or wrinkled r) is also inherited. This demonstrates Mendel's law of .
Since the chromosomes are replicated during S phase for both mitosis and meiosis, the single homologues in the daughter cells of the first meiosis division (M1) still have sister chromatids attached by a centromere. In order to make the gametes, these daughters undergo the second meiosis division (M2), so each gamete has only one copy of a haploid number of chromosomes. This M2 division is the same as