CLEP Biology Microbiology and Immunology Flashcards
6 cards from real CLEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CLEP Biology Microbiology and Immunology flashcards as text
Which bacteria form root nodules on legumes and fix atmospheric nitrogen into usable ammonia?
Answer: Rhizobium species
Rhizobium species form symbiotic relationships within legume root nodules, using nitrogenase to convert atmospheric N₂ into ammonia available to plants.
Disease transmission involving an intermediate host organism such as a mosquito is called:
Answer: Vector-borne transmission
Vector-borne transmission occurs when an intermediate organism (vector) such as a mosquito carries a pathogen and transfers it to a new host.
Penicillin kills bacteria by which mechanism?
Answer: Inhibiting cell wall (peptidoglycan) synthesis
Penicillin inhibits transpeptidase enzymes that cross-link peptidoglycan in bacterial cell walls, causing osmotic lysis of growing bacteria.
Which category of bacteria absolutely requires oxygen for growth and cannot survive without it?
Answer: Obligate aerobes
Obligate aerobes require oxygen as the final electron acceptor in aerobic respiration and cannot survive in anaerobic environments.
Koch's postulates were developed to:
Answer: Establish a causal link between a specific microorganism and a specific disease
Koch's postulates provide a rigorous set of criteria — isolation, culture, reinoculation, and re-isolation — to prove that a specific microorganism causes a specific disease.
Prions are unique infectious agents because they consist solely of:
Answer: Misfolded proteins
Prions are abnormally folded proteins that induce normal cellular proteins to misfold, causing fatal neurodegenerative diseases like Creutzfeldt-Jakob disease and scrapie.