1. The Cell Flashcards
order of classification system
domain
kingdom
phylum
class
order
family
genus
species
polymorphism
a gene with multiple alleles that corresponds to specific phenotype
speciation
formation of new species
what contributes to speciation?
inbreeding (mutations arise in one group of species but not another)
outbreeding (mating of non-relatives)
bottleneck - crisis resulting in few organisms left (not representative of original population)
specialization (members of species tailor behaviour to exploit environment)
genetic drift
happens to small species, one allele is permanently lost
viral particle
mature virus outside the host cell
capsid
protein coat on virus
do viruses have organelles?
no
which cells can viruses infect?
ones with specific receptors for that virus
how do viruses enter animal cells?
usually through receptor-mediated endocytosis
structure of virus
capsid
nucleic acid
lipid-rich protein envelope (sometimes)
structure of bacteriophage
capsid
nucleic acid
lipid-rich protein envelope
tail
base-plate
tail fibers (sometimes)
how does a bacteriophage enter a virus?
lands, attaches, eats a hole, injects nucleic acid into cell
lytic infection cycle
takes control of host cell machinery and fills cell with virus
cell bursts causing disease
virulent virus
lysogenic infection cycle
viral DNA is incorporated into host genome
when host cell replicates, viral DNA is replicated as well
temperate virus (may not show signs of infection)
becomes virulent when cell under stress and then follows lytic cycle
how are enveloped viruses formed?
from lytic cycle, they undergo reverse endocytosis and pinch off some of the membrane from the host cell
nonenveloped viruses cause…
cell lysis upon release
viruses that carry -RNA undergo how many rounds of replication?
one
how is dsRNA replicated?
separates and is replicated by RdRp
how is ssDNA replicated?
DNA polymerase makes a replicate to make dsDNA
retroviruses
can synthesize their ssRNA into dsDNA using reverse transcriptase
conjugation
transfer of a plasmid
genetic recombination
transformation
bacteria incorporate DNA from the external environment
