Pregnancy, placenta and embryonic development — NEET & JEE Questions

Question 1 · difficulty L1 · recall

Which temporary organ forms the functional connection between the developing embryo and the mother?

• A. Placenta
• B. Amnion
• C. Corpus luteum
• D. Cervix

Question 2 · difficulty L1 · recall

Which substance normally moves from maternal blood toward the fetus across the placenta?

• A. Urea produced by the fetus
• B. Oxygen
• C. Carbon dioxide produced by the fetus
• D. Creatinine produced by the fetus

Question 3 · difficulty L2 · understanding

Why is the placenta also considered an endocrine tissue?

• A. It stores all fetal blood
• B. It produces sperm cells
• C. It secretes hormones that help maintain pregnancy
• D. It replaces the maternal pituitary

Question 4 · difficulty L2 · understanding

Find the correct statement : (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 :

• A. B, C, D and E only
• B. A, C, D and E only
• C. A and E only
• D. B and C only

Question 5 · difficulty L2 · understanding

The placenta primarily functions as an interface for

• A. exchange of gases, nutrients and wastes between maternal and fetal circulations
• B. direct mixing of all maternal and fetal blood
• C. production of sperm
• D. digestion of the embryo

Question 6 · difficulty L3 · application

A hormone detected early in pregnancy helps maintain the corpus luteum so that progesterone secretion continues. Which hormone is this?

• A. Melatonin
• B. Follicle-stimulating hormone
• C. Oxytocin
• D. Human chorionic gonadotropin

Question 7 · difficulty L3 · application

During early embryonic development, repeated mitotic divisions occur without a large increase in the overall size of the conceptus. What are these divisions called?

• A. Cleavage divisions
• B. Meiotic divisions
• C. Spermatogenesis
• D. Parturition contractions

Question 8 · difficulty L3 · application

A placental defect greatly reduces transfer of oxygen and glucose but does not directly interfere with fetal chromosomes. Which consequence is most immediately expected?

• A. Failure of sperm formation in the father
• B. Immediate change in fetal chromosome number
• C. Impaired fetal growth because metabolic supply is reduced
• D. Loss of maternal ovulation during that same cycle only

Question 9 · difficulty L3 · understanding

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): During pregnancy the level of thyroxine is increased in the maternal blood. Reason (R): Pregnancy is characterised by metabolic changes in the mother. In the light of the above statements, choose the most appropriate answer from the options given below:

• A. (A) is not correct but (R) is correct
• B. Both (A) and (R) are correct and (R) is the correct explanation of (A)
• C. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
• D. (A) is correct but (R) is not correct

Question 10 · difficulty L3 · understanding

Which of these is not an important component of initiation of parturition in humans?

• A. Release of Prolactin
• B. Increase in estrogen and progesterone ratio
• C. Synthesis of prostaglandins
• D. Release of Oxytocin