The jacket of the fern antheridium is composed of: (in $cells$)

In which of the following plants is the gametophytic phase secondary?

Sporangia are associated with sporophylls. In $P$ plants,sporophylls are distinct,while in $Q$ plants,sporophylls form compact structures called strobili or cones.
$P \quad Q$

Microsporangia and megasporangia are found in the same strobilus in

Assertion $(A)$: The sporophyte phase of ferns is long-lived and dominant.
Reason $(R)$: In ferns,the sporophyte phase exists as a thallus.

Spores of $Dryopteris$ are