Fill in the blanks:
$(1)$ Genetic information containing molecules is known as ........
$(2)$ The formulas of ammonium cyanate and urea are ........ and ......... respectively.
$(3)$ The hybridisation type of carbon in methane,ethane,ethene,and ethyne is ..........,.........,......... and ......... respectively.
$(4)$ From $sp^3, sp^2$ and $sp$ hybrid orbitals,....... is most and ......... is least electronegative.

(N/A) $(1)$ The molecule containing genetic information is $DNA$ (deoxyribonucleic acid).
$(2)$ The chemical formula for ammonium cyanate is $NH_4CNO$ and for urea is $NH_2CONH_2$.
$(3)$ The hybridisation of carbon in methane $(CH_4)$ is $sp^3$,in ethane $(C_2H_6)$ is $sp^3$,in ethene $(C_2H_4)$ is $sp^2$,and in ethyne $(C_2H_2)$ is $sp$.
$(4)$ Electronegativity increases with the increase in $s$-character. Thus,$sp$ hybrid orbital is most electronegative ($50\% \ s$-character) and $sp^3$ hybrid orbital is least electronegative ($25\% \ s$-character).