Spirogyra increases its body length by the division of

$A$ spore of Spirogyra sp. after the resting period is:

Which of the following produces non-motile gametes?

Which of the following is known as the primitive plant?

Which of the following is a red alga that is not red?

$100$ zygospores,alternating with empty cells in Spirogyra,are formed under ................. conjugation and the total number of daughter filaments formed will be ..........................