While entering the neck of a fern archegonium,sperms show:

The first evolution of roots occurred in .........

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

Which of the following aquatic pteridophytes is responsible for nitrogen fixation?

Given below are the stages in the life cycle of pteridophytes. Arrange the following stages in the correct sequence.
$A.$ Prothallus stage
$B.$ Meiosis in spore mother cells
$C.$ Fertilisation
$D.$ Formation of archegonia and antheridia in gametophyte.
$E.$ Transfer of antherozoids to the archegonia in presence of water.
Choose the correct answer from the options given below.

Which of the following plants possesses vascular tissues?