Some viruses can be crystallized and their structures analyzed. One such virus is yellow mottle virus, which infects beans. This virus has a single-stranded RNA genome containing about 6300 nucleotides. Its capsid is 25-30 nm in diameter and contains 180 identical capsomeres. If the yellow mottle virus begins its infection of a cell by using its genome as mRNA, which of the following would you expect to be able to measure? A) replication rate
B) transcription rate
C) translation rate
D) formation of new transcription factors

The correct answer is 9 proteins form each of the 20 facets of this virus. A capsid is the protein shell that surrounds a virus. A capsomere is the subunit of the capsid. Depending on the virus, capsomeres arrange in many different shapes to form the capsid. The yellow mottle virus has 20 facets, this means that it has an icosahedral capsid. Since it contains 180 identical capsomeres, we can conclude that 9 proteins form each facet.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.