In which plant does vegetative propagation occur through the stem?

$(a)$ List any two methods of asexual reproduction.
$(b)$ Explain how $Spirogyra$ reproduces.

Can we find variations in an asexually reproducing organism like bacteria? Write yes or no and give a reason in support of your answer.

Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

List any two modes of asexual reproduction in animals. Under which mode of reproduction is vegetative propagation placed and why? List two advantages of vegetative propagation.

In the context of reproduction of species,state the main difference between fission and fragmentation. Also,give one example of each.