The type of reproduction that allows the change in a genetic aspect and the survival of species due to genetic variation and a more genetically prepared organisms to the envionmental factors, is known as sexual reproduction, and it's carry out by the specialized cells of organisms such as plants, and animals. This cells, known as sex cells, or gametes (sperm and egg cells) carry the required genetic load to develop a zygote after their fusion, and the development of an embryo that will end in a species' individual. dsf