In a dna molecule, what holds together nitrogenous bases from the two polymer chains?
a. phosphodiester bonds
b. ionic bonds
c. covalent bonds
d. peptide bonds
e. hydrogen bonds

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of

What is the main reason that attitudes are more often revealed in spoken rather than written language? a. in writing, we try to put the "best face" on what we write. b. we speak far more often than we write. c. in writing, we can more easily conceal our attitudes. d. in spoken language, we are often careless in our use of words.

What would most likely happen if green plants were exposed to longer days of sunlight? a. the mitochondria would produce less energy . b. the chloroplasts would produce more energy. c. the cell wall would become thicker. d. the vacuoles would quickly shrink.b. the chloroplasts would produce more energy.