Placenta is present in

With respect to derivatives of germinal layers in human beings, complete the analogy.
$Ectoderm : \text{Sweat glands} :: Endoderm :$ . . . . . . .

Which of the following statements is true regarding cleavage?

Match List-$I$ with List-$II$ related to embryonic development at various months of pregnancy:

List-$I$	List-$II$
$A$. The foetus movement starts and hair appears on the head	$I$. $24$ weeks of pregnancy
$B$. The foetus develops limbs and digits	$II$. $20$ weeks of pregnancy
$C$. The foetus develops external genital organs	$III$. $8$ weeks of pregnancy
$D$. The foetus body is covered with fine hair; eyelids separate and eyelashes are formed	$IV$. $12$ weeks of pregnancy

Choose the correct answer from the options given below:

In human beings,after .............. month of pregnancy,the embryo's heart is formed.

In the given figure,after how many days of fertilization is the part labeled as $f$ formed?