Question

if a virus were to enter a cell and destroy its ribosomes,how would the cell be affected?

Answer 1

it would not be able to produce proteins

Answer 2

The ribosomes are a key component in protein synthesis. The act of tRNA matching up to their corresponding sequences of mRNA (which is produced earlier in the protein synthesis process known as transcription), and thus producing the polypeptide chain of amino acids (which forms proteins), takes place inside of ribosomes. Therefore, with no ribosomes, there is no protein synthesis, and without protein synthesis, I doubt a cell infected with this virus could live long.

Answer 3

this is not purely a hypothtical question. the bacteria bacteroides diphtheria (while not a virus but wait a minute) synthesizes a toxin that is able to enter the cell and ribosyaltes the ribosome, yielding dysfunctional.
apoptosis ensues . that is the answer to your question

Answer 4

The ribosomes play a major role in protein synthesis. So if a virus destroys the ribosomes of a cell, it would not be able to synthesize proteins.