Help with Viral Replication - GRE Subject Test: Biochemistry, Cell, and Molecular Biology

Of the three choices, only retroviruses use reverse transcription to make a DNA copy of their RNA genomes.

DNA viruses do not need to do this because their genome already consists of DNA. RNA viruses use specialized enzymes called RNA replicases to make RNA copies of their RNA genomes, and do not go through a DNA intermediate like retroviruses.

Reverse transcriptase is used to convert RNA genomes into DNA genomes. The genome is then inserted into the host's chromosomes, where it can be transcribed numerous times to create viral proteins. Without this process, the RNA genome would have a very short-lived existence in the cell, resulting in very few viral copies.

This technique is used by retroviruses, such as HIV.

The first step in viral replication is penetration. The virus may be engulfed by the host cell or fuse with the host's membrane. The viral genetic material is released into the cytoplasm. During replication the viral genetic material is copied many times. The viral genetic material is used as a blueprint to make messenger RNA (mRNA) during the transcription stage. The mRNA is used to synthesize viral proteins. The viral genetic material and enzymes are surrounded by their protein coat during viral assembly. Finally viruses are released from the host cell by budding from the cell membrane or bursting the cell.

All of the answers are correct. Given that viral genomes are small, the proteins that they encode must be able to execute many functions. Due to high mutation rate, many splice variants, and multiple small protein binding domains, viral proteins interact extensively with each other and host proteins. This allows viral proteins to modulate host cellular activities such as inflammation, proliferation, anti-viral response, and DNA replication/transcription/translation so that viral proteins are able to replicate and are not killed by the infected cells.

In order the replicate its genome, a non retroviral RNA virus must use a polymerase that can use an RNA template to polymerize a complimentary RNA molecule; an RNA dependent RNA polymerase. Since no such enzyme exits in host cells, the virus must encode this enzyme itself.

Of the three choices, only retroviruses use reverse transcription to make a DNA copy of their RNA genomes.

DNA viruses do not need to do this because their genome already consists of DNA. RNA viruses use specialized enzymes called RNA replicases to make RNA copies of their RNA genomes, and do not go through a DNA intermediate like retroviruses.

Reverse transcriptase is used to convert RNA genomes into DNA genomes. The genome is then inserted into the host's chromosomes, where it can be transcribed numerous times to create viral proteins. Without this process, the RNA genome would have a very short-lived existence in the cell, resulting in very few viral copies.

This technique is used by retroviruses, such as HIV.

The first step in viral replication is penetration. The virus may be engulfed by the host cell or fuse with the host's membrane. The viral genetic material is released into the cytoplasm. During replication the viral genetic material is copied many times. The viral genetic material is used as a blueprint to make messenger RNA (mRNA) during the transcription stage. The mRNA is used to synthesize viral proteins. The viral genetic material and enzymes are surrounded by their protein coat during viral assembly. Finally viruses are released from the host cell by budding from the cell membrane or bursting the cell.

All of the answers are correct. Given that viral genomes are small, the proteins that they encode must be able to execute many functions. Due to high mutation rate, many splice variants, and multiple small protein binding domains, viral proteins interact extensively with each other and host proteins. This allows viral proteins to modulate host cellular activities such as inflammation, proliferation, anti-viral response, and DNA replication/transcription/translation so that viral proteins are able to replicate and are not killed by the infected cells.

In order the replicate its genome, a non retroviral RNA virus must use a polymerase that can use an RNA template to polymerize a complimentary RNA molecule; an RNA dependent RNA polymerase. Since no such enzyme exits in host cells, the virus must encode this enzyme itself.

Of the three choices, only retroviruses use reverse transcription to make a DNA copy of their RNA genomes.

DNA viruses do not need to do this because their genome already consists of DNA. RNA viruses use specialized enzymes called RNA replicases to make RNA copies of their RNA genomes, and do not go through a DNA intermediate like retroviruses.

Reverse transcriptase is used to convert RNA genomes into DNA genomes. The genome is then inserted into the host's chromosomes, where it can be transcribed numerous times to create viral proteins. Without this process, the RNA genome would have a very short-lived existence in the cell, resulting in very few viral copies.

This technique is used by retroviruses, such as HIV.

The first step in viral replication is penetration. The virus may be engulfed by the host cell or fuse with the host's membrane. The viral genetic material is released into the cytoplasm. During replication the viral genetic material is copied many times. The viral genetic material is used as a blueprint to make messenger RNA (mRNA) during the transcription stage. The mRNA is used to synthesize viral proteins. The viral genetic material and enzymes are surrounded by their protein coat during viral assembly. Finally viruses are released from the host cell by budding from the cell membrane or bursting the cell.

All of the answers are correct. Given that viral genomes are small, the proteins that they encode must be able to execute many functions. Due to high mutation rate, many splice variants, and multiple small protein binding domains, viral proteins interact extensively with each other and host proteins. This allows viral proteins to modulate host cellular activities such as inflammation, proliferation, anti-viral response, and DNA replication/transcription/translation so that viral proteins are able to replicate and are not killed by the infected cells.

In order the replicate its genome, a non retroviral RNA virus must use a polymerase that can use an RNA template to polymerize a complimentary RNA molecule; an RNA dependent RNA polymerase. Since no such enzyme exits in host cells, the virus must encode this enzyme itself.

Of the three choices, only retroviruses use reverse transcription to make a DNA copy of their RNA genomes.

DNA viruses do not need to do this because their genome already consists of DNA. RNA viruses use specialized enzymes called RNA replicases to make RNA copies of their RNA genomes, and do not go through a DNA intermediate like retroviruses.

Reverse transcriptase is used to convert RNA genomes into DNA genomes. The genome is then inserted into the host's chromosomes, where it can be transcribed numerous times to create viral proteins. Without this process, the RNA genome would have a very short-lived existence in the cell, resulting in very few viral copies.

This technique is used by retroviruses, such as HIV.

The first step in viral replication is penetration. The virus may be engulfed by the host cell or fuse with the host's membrane. The viral genetic material is released into the cytoplasm. During replication the viral genetic material is copied many times. The viral genetic material is used as a blueprint to make messenger RNA (mRNA) during the transcription stage. The mRNA is used to synthesize viral proteins. The viral genetic material and enzymes are surrounded by their protein coat during viral assembly. Finally viruses are released from the host cell by budding from the cell membrane or bursting the cell.

All of the answers are correct. Given that viral genomes are small, the proteins that they encode must be able to execute many functions. Due to high mutation rate, many splice variants, and multiple small protein binding domains, viral proteins interact extensively with each other and host proteins. This allows viral proteins to modulate host cellular activities such as inflammation, proliferation, anti-viral response, and DNA replication/transcription/translation so that viral proteins are able to replicate and are not killed by the infected cells.

In order the replicate its genome, a non retroviral RNA virus must use a polymerase that can use an RNA template to polymerize a complimentary RNA molecule; an RNA dependent RNA polymerase. Since no such enzyme exits in host cells, the virus must encode this enzyme itself.