Which nitrogen bases always pair with one another?

Which of the following substances is not involved in the chemical reaction that pro- duces smog? a. sunlight b. particulate matter c. automotive exhaust d. ozone

In terms of alternation of generations, the internal parts of the pollen grains of seed-producing plants are most similar to a ) moss sporophyteb) moss gametophyte bearing both male and female gametangiac) fern sporophyted) fern gametophyte bearing only antheridia

The term used to describe a disease-causing microorganism isa. virus.b. infection.c. pathogen.d. microbe.e. bacterium.