What is the main function of the Respiratory System? Pumping blood bringing oxygen to the cells throughout your body Supporting your muscles and protecting vital organs Taking in oxygen for the body and expelling carbon dioxide

The human respiratory system is a series of organs responsible for taking in oxygen and expelling carbon dioxide. The primary organs of the respiratory system are the lungs, which carry out this exchange of gases as we breath.

both male and female gametes are produced by meiosis of the germ cells. therefore, both male and female gametes are haploid. one male and one female gamete unite during the fertilization to form the diploid zygote. in seed bearing plants, pollen grain is the male gametophyte, which produces sperm cells.