Read the passage below and answer the questions that follow.
Tobacco Mosaic Virus Spread
Tobacco Mosaic Virus (TMV) is a viral pathogen that infects a wide range of plants, especially tobacco and tomatoes. In 2023, a comprehensive agricultural survey linked microclimate variations to localized outbreaks inside commercial glasshouses. High ambient light levels and warm greenhouse temperatures accelerate the rate of viral replication and facilitate its systemic movement through the phloem.
In one monitored glasshouse, records showed that 432 tomato plants displayed severe symptoms, including distinctive mosaic patterns on their leaves and stunted growth. Among these plants showing severe symptoms, 54 eventually died.
Furthermore, physical management practices and ventilation regimes also influence transmission. High humidity within the glasshouses increases leaf turgor and contact, promoting transmission via direct touch. Conversely, dry, windy periods outside can cause leaves to rub against structural glasshouse frames when vents are open, creating microscopic wounds that allow the virus to enter.
Tobacco Mosaic Virus is a virus. State three ways that the structure of a virus differs from the structure of a bacterium.
Calculate the mortality rate (percentage death rate) of the tomato plants with documented severe symptoms in this glasshouse in 2023. Show your working.
Identify two abiotic (non-living) factors mentioned in the passage that affect TMV replication, plant damage, or transmission.
