Conifers are adapted to tolerate extreme environmental conditions because of ..........

In which of the following is the gametophyte not an independent,free-living generation?

Male and female $Cycas$ plants show which type of growth?

Coralloid roots of $Cycas$ are useful in

Consider the following statements regarding gymnosperms and choose the correct option.
$I.$ In gymnosperms,the male and female gametophytes have an independent existence.
$II.$ The multicellular female gametophyte is retained within the megasporangium.
$III.$ The gymnosperms are heterosporous.
Of these statements:

The giant tree among the pines belongs to