1. which elements are most abundant in living organisms?
hydrogen, carbon, calcium, potassium, oxygen, and phosphorus
oxygen, calcium, phosphorus, sodium, hydrogen, and carbon
carbon, potassium, iron, magnesium, hydrogen, and nitrogen
oxygen, nitrogen, carbon, hydrogen, sulfur, and phosphorus

Describe how viruses and bacteria can be used as biological weapons. what are some of the potential threats and potential benefits? do you agree with the use of viruses and bacteria as biological weapons? why or why not?

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .

Electrons are brought to the electron transport system by the oxidation of