The observation that the bacteria genus chlamydia contains species that can only survive as intracellular parasites supports which viral origin hypothesis?
progressive
regressive
self-replicating
virus-first

Apart of the periodic table is shown. a portion of the sixteenth and seventeenth columns of the periodic table is shown. column 16 reads eight oxygen, 16 sulfur, and 34 selenium. column 17 reads nine flourine, 17 chlorine, and 35 bromine. which of the following elements is less reactive than the others? bromine (br) oxygen (o) selenium (se) sulfur (s)

The diagram shows the layers of earth. convection currents in which region influence the movement of tectonic plates

Which of the following best describes the relationship between glucose and complex molecules such as hormones?