How do Spirogyra and Mucor reproduce asexually?

Liverworts reproduce asexually by

How do organisms , whether reproduced asexually or sexually maintain a constant chromosome number through several generations ? Explain with the help of suitable example.

Rhizopus and Mucor reproduce mainly by

fungi reproduce only asexually.

Rhizopus reproduces asexually by :

(a) How do sponges reproduce asexually ? (b) Which system helps them in nutrition , respiration and excretion ? (c ) How do sponges maintain their shapes ? Explain.

Hereditary cyanobacteria reproduce asexually by