Which of the following organisms undergoes binary fission?

Which among the following is not the function of testes at puberty?
$(i)$ formation of germ cells
$(ii)$ secretion of testosterone
$(iii)$ development of placenta
$(iv)$ secretion of estrogen

What is the typical duration of a menstrual cycle in human females?

Most of the flowers in plants are of which type?

Differentiate between the following:
$(a)$ Pollen tube and style.
$(b)$ Bud of Hydra and bud of Bryophyllum.

$(a)$ Identify the organisms $A$ and $B$ and the mode of asexual reproduction exhibited by them.
$(b)$ How will an organism be benefitted if it reproduces through spores?
$(c)$ Mention the two asexual methods by which Hydra can reproduce. Explain briefly any one such method.