Some regions of a polypeptide may coil or fold back on themselves. this is called and the coils or folds are held in place by
a. tertiary structure covalent bonds
b. primary structure covalent bonds
c. tertiary structure hydrogen bonds
d. secondary structure hydrogen bonds
e. secondary structure peptide bonds

What is the farthest destination to date for a human spaceflight mission?

Where in the cell are ribosomes made?

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.