Endosymbiont
... obligate, where neither the endosymbiont nor the
host can survive without the other. One example is ... . In some cases there is specificity between
host and Symbiodinium clade. More often, however, ... embryo.
The bacteria are thought to help the
host by either synthesizing nutrients that ...
Endosymbiont
... obligate, where neither the endosymbiont nor the
host can survive without the other. One example is ... . In some cases there is specificity between
host and Symbiodinium clade. More often, however, ... embryo.
The bacteria are thought to help the
host by either synthesizing nutrients that ...
Foot and mouth disease
... , have been free of FMD for some time, its wide
host range and rapid spread represent cause for ... When such a virus comes in contact with a
host cell, it binds to a receptor site and triggers a ... the cell membrane. Once the virus is inside the
host cell, its protein coat dissolves. New viral RNA ...
Gene therapy
... instructions to produce these viruses. The
host cell will carry out these intructions and produce ... in the form of DNA. When a retrovirus infects a
host cell, it will introduce its RNA together with ... be considered part of the genetic material of the
host cell. The process of producing a DNA copy from an ...
Lambda phage
... lives in E. coli . Once the phage is inside its
host , it may integrate itself into the host's DNA . ... that look out for signs of stress in the
host cell. Stress can be a result of starvation, ... active again, excises itself from the DNA of the
host cell and enters its lytic cycle . The ...
Phage
... material into the chromosomal DNA of the
host bacterium (much like endogenous retroviruses ... cell division together with the DNA of the
host cell. They do not kill the cell, but monitor ( ... they code for) the status of their host. When the
host cell shows signs of stress (meaning it might be ...
Virus
... of existing enzymes and other molecules of a
host cell to create more virus particles. Viruses ... genes and show inheritance, but are reliant on
host cells to produce new generations of viruses. Many ... crystallized . Because viruses are dependent on
host cells for their replication they are generally ...
Endosymbiotic theory
...
Mitochondria utilize a different genetic code than the eukaryotic
host cell; this code is very similar to bacteria and Archaea .
They are ... This is consistent with an increased dependence on the eukaryotic
host after forming an endosymbiosis.
Chloroplasts appear in very different ...
Mitochondrion
... membrane, along with polypeptides encoded by genes that reside in the
host cell's nucleus .
Mitochondrial functions
Although the primary ... and NADH (glycolysis is performed outside the mitochondria, in the
host cell's cytosol ). This metabolism can be performed in two very different ...
Mitochondrion
... membrane, along with polypeptides encoded by genes that reside in the
host cell's nucleus .
Mitochondrial functions
Although the primary ... and NADH (glycolysis is performed outside the mitochondria, in the
host cell's cytosol ). This metabolism can be performed in two very different ...
Parasitology
... of parasites can reveal information about their relationship with the
host (eg. influences on mortality rate) and relationships between different populations of
host species. This technique is commonly applied in fisheries biology , where ...
Prion
... prions, agents of spongiform encephalopathies
Disease name
Natural
host
Prion name
PrP isoform
Scrapie Sheep and goats Scrapie ... Sc
* or variant
Fungal prion
Protein
Natural
host
Prion name
Ure2p Saccharomyces cerevisiae [URE2+] prion
...
Prophage
... its integrated status. Its genome can be integrated into the bacterial
host chromosome or exists as an extrachromosomal plasmid . When stress in the
host is detected, the phage enters its reproductive cycle.
...
Antibiotic
... these was a sulfonamide , prontosil , which was used to treat infections in humans, where its effect was found to be due to its conversion in the
host to the active form, sulfanilimide . By today's more broad definition, this would likely qualify as the first successful use of an oral antibiotic. ...
Antigenic shift
... the same cell simultaneously, their protein capsids and lipid envelopes are removed, exposing their RNA , which is then transcribed to DNA . The
host cell then forms new viruses that combine antigens; for example, H3N2 and H5N1 can form H5N2 this way. Such combinations caused, for instance, the ...
Escherichia coli
... coli arise all the time from the natural biological process of mutation , and some of those strains have characteristics that can be harmful to a
host animal. Although in most healthy adult humans such a strain would probably cause no more than a bout of diarrhea , and might produce no symptom at ...
Ebola
... of 5 nm. 7 nm glycoprotein spikes that are 10 nm apart from each other are present within the outer envelope of the virus, which is derived from the
host cell membrane. Each viral particle contains one molecule of single-stranded, negative-sense RNA , which encodes the seven viral proteins.
...
Edward Jenner
... .
Jenner was a keen observer of nature and he was one of the first to write about the baby cuckoo's action of pushing the eggs and the young of its
host out of the nest so that the baby cuckoo was the only one to receive food from its foster parents. It was for this observation that he was elected a ...
Gene
... his book, The Selfish Gene , that to be successful genes need have no other "purpose" than to propagate themselves , even at the expense of their
host organism's welfare. A human that behaved in such a way would be described as "selfish," although ironically a selfish gene may promote altruistic ...
Genomics
... an organism. Because of the success of large-scale quantitative biology projects such as genome sequencing, the suffix "ome" has been extended to a
host of other contexts. The only other "ome" to shake its origin as a buzzword is proteome , the totality of proteins ( expressed genes that are ...
Hershey-Chase experiment
... of viruses
More detailed description
Hershey and Chase knew that T2 consisted of only DNA and protein, and that they somehow manipulated
host cells to produce new phages , but did not know if DNA or protein was responsible.
Hershey and Chase radioactively labeled E.Coli and T2 with ...
Immune system
... first defense includes barriers to infection such as skin and mucus coating of the gut and airways, physically preventing the interaction between the
host and pathogen. Pathogens which penetrate these barriers encounter constitutively expressed anti-microbial molecules that restrict the infection.
...
Infertility
... resulted in an increase in multiple births , provoking ethical analysis because of the link between multiple pregnancies, premature birth , and a
host of health problems.
Religious leaders' instructions on fertility treatments.
Psychological impact
Infertility may have a profound ...
Life
... mules are not alive as they are sterile and cannot reproduce.
viruses are not alive as they do not grow and cannot reproduce outside of a
host cell.
Biologists who are content to focus on terrestrial organisms often note some additional signs of a "living organism", including these:
...
Lytic cycle
... then injects its genetic material, which can be either DNA or RNA , into the cell.
Growth
The viral nucleic acid takes over and uses the
host cells organelles to make many copies of the virus. In the case of DNA viruses, the DNA transcribes itself into messenger RNA (mRNA) molecules ...
Microsatellite
... at an especially high frequency during each round of mitosis . Hence a tumour cell line might show a different genetic fingerprint from that of the
host tissue.
See also: minisatellite , mobile element , transposon , short interspersed repetitive element , long interspersed repetitive element , ...
Muller's ratchet
... be that the mutation is deleterious, but not lethal. Furthermore, the organism with the mutation may have another advantageous mutation -- or its
host may have an advantageous mutation -- that will lead to their survival despite the deleterious mutation. Because there is no possibility for genetic ...
Plasmid
... resistances ( 1 & 2 ) and an ori( 3 )
Episomes
Episomes are plasmids that can integrate themselves into the chromosomal DNA of the
host organism (Fig. 3). For this reason, they can stay intact for a long time, be duplicated with every cell division of the host, and become a basic ...
Retrovirus
... outside of retroviruses has been found in almost all eukaryotes, enabling the generation and insertion of new copies of retrotransposons into the
host genome.
Because reverse transcription is missing the usual "proofreading" of DNA transcription, this kind of virus mutates very often. This ...
Robert Koch
... closely. He invented methods to purify the bacillus from blood samples and grow pure cultures. He found that, while it could not survive outside a
host for long, anthrax built persisting spores that could last a long time. These spores, embedded in soil, were the cause of unexplained "spontaneous" ...
Species
... species is saying something more than classificatory about them.
After thousands of years of use, the concept remains central to biology and a
host of related fields, and yet also remains at times ill-defined and controversial.
Implications of assignment of species status
The naming of a ...
Stem cell
... Embryonic stem cell researchers are currently attempting to grow the cells beyond the first stages of cell development, to overcome difficulties in
host rejection of implanted stem cells, and to control the multiplying of implanted embryonic stem cells, which otherwise multiply uncontrollably, ...
Symbiosis
... interaction between two organisms living together in more or less intimate association or even the merging of two dissimilar organisms.
The term
host is usually used for the larger (macro) of the two members of a symbiosis. The smaller (micro) member is called the symbiont (alternately, ...
Tobacco mosaic virus
... indicating that this is the most stable structure (the one with the lowest free energy), and likely the natural assembly mechanism within the
host cell.
The crystalographer Rosalind Franklin worked for Stanley for about a month at Berkeley , and later designed and built a model of TMV for ...
Tobacco mosaic virus
... indicating that this is the most stable structure (the one with the lowest free energy), and likely the natural assembly mechanism within the
host cell.
The crystalographer Rosalind Franklin worked for Stanley for about a month at Berkeley , and later designed and built a model of TMV for ...
Varicella zoster virus
... including VZV encephalitis . Even when clinical symptoms of varicella have resolved, VZV remains dormant in the nervous system of the
host in the trigeminal and dorsal root ganglia . In about 10-20% of cases, VZV later reactivates later in life to produce herpes zoster (shingles) ...
Virus classification
... Viruses can be classified in several ways, such as by their geometry, by whether they have envelopes, by the identity of the
host organism they can infect, by mode of transmission, or by the type of disease they cause. The most useful classification is probably by the type of ...