In brown algae,the brown colour is due to the presence of:

Algae reproduce by which of the following methods?

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 produces non-motile gametes?

Which pigment is present in all algae?

The replicate septum of $Spirogyra$ is characterised by: