Because they started breeding more started coming and there was no big threats
PATHWAY (ROUTE) TAKEN BY CO2:
blood(within capillary) >wall of capillary >wall of alveolar >moisture lining >alveolar space >bronchiole >bronchus >trachea >nose
PATHWAY (ROUTE) TAKEN BY O2:
nose >trachea >bronchus >bronchiole >alveolar space >moisture lining >wall of alveolar >wall of capillary >blood(within capillary)
Answer:
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Explanation:
Place the steps for the formation of the enzyme pepsinogen in the correct order. The DNA strands unwind, and RNA polymerase binds to the. template strand. The mRNA undergoes intron.