Where does gas exchange occur in the respiratory system?
a. bronchi
b. alveoli
c. trachea
d. epiglottis

Consider darwin's first writings on the theory of natural selection. an important point of darwin's essay on the principle of population, written in 1798, was a peer's observation that in nature plants and animals produce far more offspring than can survive, this observation can be attributed to a) charles lyell. b) thomas malthus. c) jean-baptiste lamarck. d) johann friedrich meckel.

Select the correct answer from each drop-down menu proteins are

_is a product of the first stage of photosynthesis.atpglucosecarbon dioxidewater