Questions

Desertification is a type of land degradation in which a relatively dry area of land becomes increasingly arid, typically losing its bodies of water as well as vegetation and wildlife.

Conversion of a grassland or an already arid land into a desert through indiscriminate human actions magnified by droughts.

Hence, forest improving to deserts is refers to desertification.

Packet filter is a standard router equipped with some extra functionality. The extra functionality allows every incoming or outgoing packet to be inspected. Packets meeting some criterion are forwarded normally. Those that fail the test are dropped

Saliva is produced by the salivary gland which helps in food digestion.

Option A) contains fluoride to harden the tooth enamel is not the function of saliva.

A rift valley is formed either due to upheaval of blocks on either sides of a fracture or due to subsidence of block between them.