Which type of immunoglobulins are seen in dimeric form?

Q. Which type of immunoglobulin is / are abundantly found in foetus?

Q. If following molecules undergo dimerization then find the value of $\frac{YZ}{X}$.
(i) $Cl{O}_3$, (ii) $OF$, (iii) $Ga{H}_3$, (iv) $AlC{l}_3$, (v) $IC{l}_3$, (vi) $Be{H}_2$, (vii) $N{O}_2$Where,
$X=$ Number of molecules which are hypervalent in dimeric form.
$Y=$ Number of molecules which com octet in dimer form.
$Z=$ Number of molecules which are hypovalent in dimeric form.

Q. Find the value of $\frac{y.z}{x}$, if the following molecules undergo dimerization:
I. $Cl{O}_3$
II. $O{F}_2$
III. $Ga{H}_3$
IV. $AlC{l}_3$
V. $IC{l}_3$
VI. $Be{H}_2$
VII. $N{O}_2$
$x$: Number of molecules which are hypervalent in dimeric form
$y$: Number of molecules with a complete octet in dimeric form
$z$: Number of molecules which are hypovalent in dimeric form

Q. Which of the following immunoglobulins are present in high quantities in human milk?

Q. Following are the types of immunoglobulin and their functions. Which one of the following is incorrectly paired?