Match each step in the nitrogen cycle to its description. bacteria convert ammonia
to nitrites and nitrates
bacteria break down waste
products and return nitrogen
to the soil
bacteria convert nitrates
into nitrogen gas
plants and animals take in
and use nitrogen compounds
bacteria convert atmospheric
nitrogen to ammonia
nitrification
nitrogen fixation
>
ammonification
>

What is the answer for the complicated molecules that make up living things usually contain carbon. why is carbon so important in these molecules?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

Which best describes a benefit of using dna technology in medicine? a) medicine can be produced in mass quantities. b) medicine can be distributed at a reduced cost. c) medicines have fewer side effects. d) medicines are resistant to antibiotics.