OET READING PART B Q3
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OET READING Mini-MOCK TEST
The Hepatitis B virus (HBV), which belongs to the hepadnavirus family, is a small circular DNA virus containing a nucleocapsid and an envelope. HBV nucleocapsid contains a relatively small and incompletely double stranded 3.2 Kb DNA genome, viral polymerase and core protein. Its envelope is composed of viral surface proteins enclosed by a lipid membrane from host cells. In the serum of infected patients, there are both mature virion with viral DNA and subviral particles without viral DNA .Sub viral particles are overwhelmingly in excess to infectious particles, which is the majority of the two types. The life cycle of HBV is believed to begin when the virus attaches to the host cell membrane via its envelope proteins. Then, the viral membrane fuses with the cell membrane and the viral genome is released into the cells. After the viral genome reaches the nucleus, the viral polymerase converts the partial double stranded DNA (dsDNA) genome into covalently closed circle DNA (cccDNA)....
