Algae with floridean starch as reserve food material is also characterised by

$Ulothrix$ can be described as:

Select the correct option from the given list regarding algal classes and their stored food materials:
$(1)$ Rhodophyceae - Pyrenoids
$(2)$ Phaeophyceae - Laminarin
$(3)$ Bryophytes - Mannitol
$(4)$ Chlorophyceae - Floridean starch

Describe the types of reproduction in red algae (Rhodophyceae).

The zygospore of $Spirogyra$ produces:

$Spirogyra$ is a