Which is the dominant and active phase in the alternation of generations in algae?

The unique feature of Thallophyta is .........

Which of the following is known as pond silk?

$A$: In $Fucus$,the sporophytic phase is limited to the zygote only.
$R$: In $Fucus$,the sporophytic phase is photosynthetic and independent.

Chlamydomonas does not occur in

In $Spirogyra$,sometimes the gametes behave directly as zygospores without fusion. Such reproductive bodies are called