Which of the following shapes is not found in the chloroplasts of Chlorophyceae?

The chloroplasts of algae usually lack

Green algae contain:

Consider the following statements regarding reproduction in class-$Chlorophyceae$.
$I.$ Asexual reproduction is mainly by flagellated zoospores produced in zoosporangia.
$II.$ The sexual reproduction shows considerable variation in the type and formation of sex cells and it may be isogamous,anisogamous and oogamous.
Which of the statements given above are correct?

Algae float in the water during day time and sink during night time because

Which alga exhibits a haplo-diplontic life cycle?