Which of the following structures is lacking in the placenta?

Which of the following is $NOT$ true for the blastocyst?

Find the correct statements :
$A.$ In human pregnancy,the major organ systems are formed at the end of $12$ weeks.
$B.$ In human pregnancy the major organ systems are formed at the end of $8$ weeks.
$C.$ In human pregnancy heart is formed after one month of gestation.
$D.$ In human pregnancy,limbs and digits develop by the end of second month.
$E.$ In human pregnancy the appearance of hair is usually observed in the fifth month.
Choose the correct answer from the options given below.

The embryonic body form stage is characterized by:

Choose the incorrect pair:

The foetus develops its limbs and digits in . . . . . . during embryonic development.