What is the main function of the circulatory system in multicellular organisms?

a) to bring oxygen into the lung

b) to put carbon dioxide into all blood vessels

c) to expel waste products from the body

d) to transport materials throughout the body

What must be true for natural selection to heppen

Does anyone know what a poms statement is for biology? i don't know what it is and i have an assignment on it tomorrow, will award the best answer a brainliest!

Cladistics is a way of classifying organisms by examining the characteristics of their ancestors and descendants and depicting the relationships in a cladogram. which of the following best describes a challenge in classifying organisms this way? a. there are millions of species on earth, and a cladogram is not a practical means for classifying all of them. b. it is impossible to tell which organisms are most closely related to each other using a cladogram. c. cladograms are detail-oriented and do not provide a useful understanding of evolutionary relationships. d. there is a limited number of ways to organize the information, so most cladograms end up looking very similar.