Human fetal hemoglobin is characterized by:

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

Which of the following hormones plays a crucial role in the maintenance of pregnancy?

By the end of about .......... weeks,the body is covered with fine hair.

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.

Following changes can be seen in the first trimester of pregnancy,$EXCEPT$: