The main function of the respiratory system is to allow the exchange of gases between the atmosphere and the lungs.
Hence,the only structure that carries out this function is the alveoli as other structures such as the nose,trachea and pharynx transport gases to the alveoli just so that it can can out its function.
Answer:
they can cause a lot of harm in human body
Explanation:
based on research, a virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism.
Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms.
and lots more all can do a lot of damage to the human body they can even take someone's life.
In human, Oogenesis in comparison to spermatogenesis is different in that Oogenesis does not complete meiosis until after fertilization, but spermatogenesis is complete before the sperm leave the body. Oogenesis is the process by which the female gametes, or ova are created in the female's ovary. Spermatogenesis is the process in which males synthesis sperms. The two process are part of gametogenesis which involves meiosis type of cell division, in which a diploid cell divides into four haploid daughter cells.
Alternative energy sources are those that do not deplete natural resources and do not harm the environment.
Options A, B, and C are all fossil fuels, which we know can be depleted and harm the environment.
The only valid option here is D, Geothermal energy.
Geothermal energy is both renewable and environmentally friendly.
