Explain how the passage of genes from parents to offspring, in the form of particular alleles, ensures perpetuation of parental traits in offspring and, at the same time, genetic variation among offspring.

Generally the genetic composition of every individual are conserved in the DNA, which are expressed as Genes. The part of DNA that codes fro a particular protein is called Gene. These genes were inherited from individual parents by offspring during genetic processes, and are passed to next generation of initiated by the offspring. Therefore the type of characteristics or traits manifested by an individual are results of gene expressed in DNA.

These traits are usually encoded as transcribed bases in mRNA, and when fully translated they are expressed as proteins. Thus each trait are translated protein. This explains the forms of transport of genetic materials from parents to offspring.

The inherited traits can expressed itself fully in the offsping irrespective of other characteristics, e. g a white man who marries a black woman and all the kids are white with long hair, shows dominance of the white allele, expressed as protein, despite the presence of the black allele. such black allele is said to be recessive.

The independent assortment of genes at meiosis, the crossing over at prophase 1, and separation of the chromosomes at Anaphase 1 and II together with random fertilization by million of genetically varied haploid sperm cells ensured that no two individual are 100 % genetically identical even if they are from the same parents.

The crossing over of genetic materials ensures mixing of these material to give a genetically unique organisms from mixture of the parents DNA. In addition the independent assortment of genes ensures that homologous chromosomes do not continue their 'journey' into the same sex-cells, and therefore the genetic component of the new sex-cells (sperm or oocytes) and the resultant offspring varies

Furthermore, segregation of genes into different sperm cells and eggs cells ensures random distribution of the DNA in million of sperm cells and therefore varied traits because this DNA distribution can not be the same in each sperm or egg cells, ensuring great variation in the eventual offspring.