Which of the following algae produce carrageen?

Which method of sexual reproduction is observed in the alga shown in the given figure?

Who is regarded as the "Father of Indian Phycology"?

Some characters of algae are given below:
$a.$ Floridean starch
$b.$ Sulphated phycocolloids in cell wall
$c.$ Alginic acid
$d.$ Trumpet hypha
$e.$ Haplodiplontic life cycle
$f.$ Isomorphic alternation of generation
$g.$ Fucoxanthin
$h.$ Phycoerythrin
$i.$ Zygotic meiosis
$j.$ Two anterior flagella
Which of the given set of characters belongs to $Laminaria$?

The plants in which vascular tissues are absent or poorly developed and well-developed aerenchyma is present,are:

In $Spirogyra$,a ladder-like structure is formed during: