The thallus of $Volvox$ is called

The Indian species of $Spirogyra$ in which Prof. Iyengar discovered direct lateral conjugation is:

Which pigment is present in red algae in higher proportion?

Which of the following organisms cannot fix nitrogen?
$A.$ Azotobacter
$B.$ Oscillatoria
$C.$ Anabaena
$D.$ Volvox
$E.$ Nostoc
Choose the correct answer from the options given below:

Which of the following is an unsuitable habitat for algae?

In algae,sexual reproduction takes place through the fusion of two