Question 1

Which of the following best describes the difference between the embryonic and fetal periods of human development?

Accepted Answer

The embryonic period is from week 3 to week 8, when organogenesis occurs, while the fetal period is from week 9 until birth, characterized by growth and maturation of organ systems.

Question 2

During fertilization, which structure must the sperm penetrate immediately before binding to the oocyte’s plasma membrane?

Accepted Answer

Zona pellucida

Question 3

Which hormone is primarily responsible for maintaining the corpus luteum and progesterone secretion during the first trimester of pregnancy?

Accepted Answer

Human chorionic gonadotropin (hCG)

Question 4

A patient undergoes amniocentesis at 15 weeks gestation. What is the primary purpose of this procedure?

Accepted Answer

To test for genetic abnormalities in the fetus

Question 5

Which extraembryonic membrane forms the main embryonic part of the placenta and encloses all other membranes?

Accepted Answer

Chorion

Question 6

Which of the following is a direct result of gastrulation during the third week of embryonic development?

Accepted Answer

Formation of the three primary germ layers: ectoderm, mesoderm, and endoderm

Question 7

A newborn fails to close the foramen ovale after birth. Which system will be most affected?

Accepted Answer

Circulatory system

Question 8

Which hormone is responsible for stimulating uterine contractions during labor through a positive feedback mechanism?

Accepted Answer

Oxytocin

Question 9

Which germ layer gives rise to the nervous system and epidermis?

Accepted Answer

Ectoderm

Question 10

A premature infant born at 24 weeks is placed in a neonatal intensive care unit (NICU). Which developmental milestone makes survival possible at this stage?

Accepted Answer

The lungs are developed enough to allow gas exchange with medical support.

Question 11

Which of the following best explains why the cluster of cells formed during cleavage remains the same size as the original zygote?

Accepted Answer

Cells divide rapidly without increasing in size due to limited cytoplasm.

Question 12

Which of the following is a function of the amniotic cavity and its fluid?

Accepted Answer

Protects the embryo from trauma and allows symmetrical muscle development

Question 13

A woman in her third trimester experiences increased cardiac output, tidal volume, and glomerular filtration rate (GFR). What is the primary reason for these physiological changes?

Accepted Answer

To meet the increased metabolic demands of the growing fetus

Question 14

Which of the following events marks the beginning of the postnatal period?

Accepted Answer

Birth of the newborn

Question 15

Which hormone is responsible for stimulating milk production after birth, and why is its effect dampened during pregnancy?

Accepted Answer

Prolactin; its effect is dampened by high progesterone levels during pregnancy

Question 16

Which of the following best describes the role of the placenta during fetal development?

Accepted Answer

It acts as a protective barrier, facilitates nutrient and gas exchange, and secretes hormones such as hCG, estrogen, and progesterone.

Question 17

Which of the following is a teratogen?

Accepted Answer

Alcohol

Question 18

Which stage of labor is characterized by the dilation of the cervix to 10 cm and the rupture of the amniotic sac?

Accepted Answer

First stage (dilation)

Question 19

Which structure connects the embryo to the placenta and allows for the exchange of nutrients and wastes via diffusion?

Accepted Answer

Umbilical cord

Question 20

Which of the following best explains why the fetus is less susceptible to harmful substances during the fetal period compared to the embryonic period?

Accepted Answer

Most organ systems have already formed, so the risk of major structural defects is reduced.

Chapter 27: Human Development – From Fertilization to Birth and Beyond

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