Which bacterial modification allowing the bacteria to survive harsh times, like dessication?

The correct answer is endospore and capsule.

Explanation:

Bacteria can do modification in them during harsh conditions which protect them from the harsh time. These modifications are the formation of endospores or capsules.

Endospore is the hard and non-reproductive structure formed outer to the cell wall by mainly bacteria of phylum firmicutes in the absence of nutrients. Endospore helps the bacteria to remain dormant for several years until the right condition comes.

Capsule is a gelatinous layer secreted by bacterial cell which is made up of polysaccharides. It forms outer to cell wall and protects the bacteria from desiccation and engulfment by phagocytes.

the dark variety, as they are not visible on the dark tree barks

explanation: