chap 24 bio

when a cell reproduces by developing a bulge that enlarges and separates from the mother cell, it is reproducing by _________________

asexual reproduction

a __ consists of a short segment of nucleic acid with a protein coat

virus

how do human viruses enter human cells?

Proteins surround the package, which is called a capsid. Some viruses have an added layer of lipids that coat the capsid. Little extensions on the virus are called antigens, which help the virus hunt down the target host cell

the protein coat of a virus is called the ____________

capsid

________________ conversion occurs when a bacterium carrying viral genes takes on new, atypical characteristics

lysogenic

how do viral proteins damage host cells

may enter the permeability of the plasma membrane or may inhibit synthesis of host's nucleic acids or proteins

viroids cause a variety of plant diseases and are composed only of

nucleic acid and/or protein

a virus that infects a bacterium is called a ______

phage (bacteriophage)

viral infections in humans spread via the circulatory system. Viral infections in plants spread from cell to cell by _______________

plasmodesmata

the specificity of viruses to different types of cells is due to __________ sites on the host cell

receptor

the 5 stages of a lytic infection are attachment, penetration, ______, assembly, and release

replication and synthesis

how do retroviruses differ from other RNA viruses

retroviruses utilize an enzyme to produce DNA, from the RNA, which can be inserted into the host genome. RNA viruses that do not function as a retrovirus skip the DNA intermediate and replicate in the cytoplasm.

what is a temperate bacteriophage?

they do not immediately destroy the host; alternate b/w a lytic cycle and lysogenic cycle

what is a virulent (lytic) phage?

they have only lytic lifecycles; infection results in the host cell's death (due to lytic destruction-the phage replicates itself and then bursts the cell, releasing many copies