Modern-day plants are considered to be evolved from which of the following groups?

Each plant or group of plants has some phylogenetic significance in relation to evolution. $Cycas$,one of the few living members of gymnosperms,is called the 'relic of the past'. Can you establish a phylogenetic relationship of $Cycas$ with any other group of plants that justifies the above statement?

During which geological period did the order $Gnetales$ of gymnosperms evolve?

Nitrogen fixation occurs in coralloid roots of $Cycas$ with the help of:

$Ephedrine$ is obtained from..........

The plant of $Pinus$ is: