Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history? a) polyphyletic taxa b) paraphyletic taxa c) monophyletic taxa d) two of the responses are correct

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

he movement of air through earth's or any planet's atmosphere is called wind, and the main cause of earth's winds is uneven heating by the sun. this uneven heating causes changes of atmospheric pressure, and winds blow from regions with high pressure to those with low pressure.

i hope this : )