Organisms of which of the following kingdom do not have a nuclear membrane?

Which group of organisms is both $CO_2$-fixing and $N_2$-fixing?

Which of the following are concerned with eubacteria?
$(1)$ Methanogens $(2)$ Anabaena $(3)$ $N_2$ fixation $(4)$ Thermoacidophiles $(5)$ Eukaryotes $(6)$ Diatoms $(7)$ Gelatinous sheath $(8)$ Heterocyst

Which of the following organisms lacks a well-defined nucleus?

The process in which viruses are involved in sexual reproduction of bacteria is called

The name $Asterococcus \text{ } mycoides$ was given to mycoplasma by: