Intrapleural pressure during expiration.

Intrapleural pressure is the air pressure in the pleural cavity and also exists between visceral and parietal pleurae. This pressure majorly depends on ventilation phase, the volume of the intrapleural cavity and atmospheric pressure. During expiration, the Intrapleural pressure in the pleural cavity becomes less negative which is commonly known as negative pressure.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides