Identify the statements which are not correct with respect to embryonic development:
(A) By the end of 12 weeks the body of foetus is covered with fine hair
(B) The first sign of growing foetus is the appearance of heart beat
(C) Foetus develop limbs and digits by the end of second month of pregnancy
(D) The ectoderm, mesoderm and endoderm are formed after first trimester of pregnancy
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A), (D)
(A) By the end of 12 weeks the body of foetus is covered with fine hair — Not correct. The body is covered with fine hair by the end of 24 weeks.
(B) The first sign of growing foetus is the appearance of heart beat — A correct statement. Heart sounds can be noticed after one month.
(C) Foetus develop limbs and digits by the end of second month of pregnancy — A correct statement.
(D) The ectoderm, mesoderm and endoderm are formed after first trimester of pregnancy — Not correct. The germ layers form very early, soon after implantation.
NCERT Extract:
Pregnancy and Embryonic Development – “… The human pregnancy lasts 9 months. … Find out. In human beings, after one month of pregnancy, the embryo’s heart is formed. The first sign of growing foetus may be noticed by listening to the heart sound carefully through the stethoscope.”