Which method of asexual reproduction occurs in $Spirogyra$?

Which method of asexual reproduction is observed in $Spirogyra$?

The process of spore formation takes place in many simple multicellular organisms which have certain reproductive parts that can be identified.
$(a)$ Name the organism using this process.
$(b)$ Name the reproductive and non-reproductive parts of such organisms.

Which among the following diseases is not sexually transmitted?

Which of the following is the correct sequence of events of sexual reproduction in a flower?

What is produced by the fusion of a male gamete and a female gamete?