What structures of the respiratory system prepare air for entry into the lungs?

Aboy with an extra x chromosome probably has which of the following syndromes?

Solutions to environmental problems in europe must

According to theories of how life began, how did early organic molecules begin to separate from the outside world? a: specialized enzymes were required b: chains of amino acids created a barrier c: formation of microspheres or vesicles d: rna catalyzed the formation of membranes