AP Bio Ch 19 & 20 Vocab

• Virus

  Infectious particle that replicates in a cell; DNA or RNA enclosed in a capsid
• Capsid

  Protein shell around viral genome
• Viral Envelope

  Membrane enclosing a viral genome, cloaks the capsid
• Host Range

  The limited number of host cells a virus can infect
• Lytic Cycle

  Phage replicative cycle releasing new phages, kills the host cell
• Lysogenic Cycle

  Replicates the phage genome without killing the host
• Retrovirus

  RNA virus that replicates by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome
• Vaccine

  Harmless pathogen that stims a host's immune system to mount defenses against the pathogen
• DNA Sequencing

  Determines the complete nucleotide sequence of a gene or DNA segment
• Gene Cloning

  Makes copies of a gene
• Genetic Engineering

  Manipulation of genes for practical purposes
• Restriction Enzyme

  Endonuclease that cuts DNA at specific nucleotide sequences
• PCR

  Technique for amplifying DNA in vitro by incubating it
• Plasmid

  Small, circular DNA molecules in bacteria that are replicated separately from bacterial chromosome
• Stem Cells

  Unspecialized cells that can produce cells that undergo differentiation
• Gene Therapy

  Introduction of genes into an afflicted individual for therapeutic purposes