1.true
2.true
3.fasle
4.true
5.false
6.true
A. Immune system
It helps our bodies fight everything that comes in our path.
Bacteria, archaea, plants, protists, animals, and fungi, can use cellular respiration.
And the main ones that use celluar respiration are autotrophs and heterotrophs.
Hope I helped you out (:
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.