ch 21 vocab

alternations of generations

life cycle that has two alternating phases—a haploid (N) phase and diploid (2N) phase

virus

particle made of proteins, nucleic acids, and sometimes lipids that can replicate only by infecting living cells

bacteriophage

type of virus that infects bacteria

retrovirus

RNA virus that contains RNA as its genetic information

chitin

complex carbohydrate that makes up the cell walls of fungi; also found in the external skeletons of arthropods

prophage

bacteriophage DNA that is embedded in the bacterial host's DNA

fruiting body

reproductive structure of a fungus that grows from the mycelium

flagellum

structure used by protists for movement; produces movement in a wavelike motion

antibiotic

a group of drugs used to block the growth and reproduction of bacterial pathogens

prokaryote

unicellular organism that lacks a nucleus

capsid

protein coat surrounding a virus

vaccine

preparation of weakened or killed pathogens used to produce immunity to a disease

pathogen

disease causing agent

mycelium

densely branched network of the hyphae of a fungus

binary fission

type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells

hypha/ae

one of many long, slender filaments that makes up the body of a fungus

lichen

symbiotic association between a fungus and a photosynthetic organism

cilium

short hairlike projection that produces movement

endospore

structure produced by prokaryotes in unfavorable conditions; a thick internal wall that encloses the DNA and a portion of the cytoplasm

mycorrhiza

symbiotic association of plant roots and fungi

lytic infection

type of infection in which a virus enters a cell, makes copies of itself, and causes the cell to burst

lysogenic infection

type of infection in which a virus embeds its DNA into the DNA of the host cell and is replicated along with the host cell's DNA

conugation

process in which paramecia and some prokaryotes exchange genetic information