Answer: The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress.
Assuming purple is dominant, the genotypes of the parents must be Pp and pp, such that half the progeny have the dominant allele (P_) and half have the recessive phenotype (pp) 25% possibility of white-flowered plant life and 75% possibility of pink ones
Viruses are not always classified as living cells because they cannot live independently. They rely on a host to provide all resources to live, without a host they are in a dormant, near dead like state. Therefore it has to define a virus as dead or alive as it may or may not have a host.