an organism is heterozygous at two genetic loci on different chromosomes explain how these alleles are transmitted by process of mitosis to daughter cells

Replication is seen at the interphase/S phase of cell cycle to produce 2 identical chromatids.

Prophase: nuclear envelope is not visible; mitotic spindle develops; chromatin fibers are farther tightly coiled, producing discrete chromosomes which can be seen with the aid of a light microscope.

During metaphase, chromosomes moves to the center of the cell; unpaired chromosomes adhere at spindle fibers (microtubules) individually;

During anaphase, the spindle fibers begin to shorten and separation of chromatids occurs; via cytokinesis, a cleavage furrow or cell plate may lead to compartmentalization to form 2 genetically identical daughter cells;

The daughter nucleus of each has all alleles still available in each.