What is the dominant phase in the life cycle of algae?

Identify the algae shown in the given figure.

What is the term used for a plant body that lacks tissues and organs?

Consider the following statements:
$I$. They reproduce asexually by non-motile spores and sexually by non-motile gametes.
$II$. In this class,sexual reproduction is oogamous and accompanied by complex post-fertilisation developments.
$III$. The common members are $Polysiphonia$,$Porphyra$,$Gracilaria$ and $Gelidium$.
The above characteristics belong to which class of algae?

Zygospore is

In which plant group are the reproductive organs not surrounded by a layer of sterile cells?