In which of the following are the sex organs found to be exposed?

$A$: Algae are autotrophic in terms of nutrition.
$R$: Algae contain chlorophyll and other photosynthetic pigments.

$Ulothrix$ can be described as:

Give differences: Brown Algae (Phaeophyceae) and Red Algae (Rhodophyceae).

The cell wall of $Spirogyra$ is made up of

$100$ zygospores,alternating with empty cells in Spirogyra,are formed under ................. conjugation and the total number of daughter filaments formed will be ..........................