If the two alleles of an inherited pair differ, then one determines the organism's appearance and is called the dominant allele; the other has no noticeable effect on the organism's appearance and is called the recessive allele.
A sperm or egg carries only one allele for each inherited character because the two members of an allele pair segregate from each other during the production of gametes. This statement is now known as the law of segregation. When egg and sperm unite at fertilization, each contributes its alleles, restoring the paired condition in the offspring.
Independent assortment is the random assortment of chromosomes during
the production of gametes, the results are genetically unique individual
In a lot of, if not most cases a person has 2 copies of a gene in their
cells. When your body makes gametes (egg or sperm) the gamete only gets 1
copy of the gene. The law of independent assortment is saying that
whichever copy of that gene goes into the gamete is random, and also
that the genes for 2 different traits (say... height and eye color) are
inherited independently of each-other. I.E. not all short people have
brown hair, and not all freakishly tall people blue eyes. This law is
always true unless the genes are linked, which basically means that
they're located very close together on the same chromosome, and they are
almost always inherited together. An example being that red haired
people generally have a very fair complexion.