Question 1

Which of the following best describes the process of fertilization in humans?

Accepted Answer

Fusion of two haploid gametes, each containing 23 chromosomes, to form a zygote with 46 chromosomes.

Question 2

During which stage of prenatal development do the rudiments of all major organ systems appear?

Accepted Answer

First trimester

Question 3

What is the correct sequence of events during the first trimester of development?

Accepted Answer

Cleavage → Implantation → Placentation → Embryogenesis

Question 4

Which structure is responsible for the exchange of nutrients and wastes between maternal and embryonic blood?

Accepted Answer

Placenta

Question 5

What is the function of the syncytiotrophoblast during implantation?

Accepted Answer

It erodes a path through the uterine epithelium by secreting hyaluronidase.

Question 6

Which of the following best describes the role of the umbilical cord?

Accepted Answer

It connects the fetus and placenta, containing allantois, placental blood vessels, and yolk stalk.

Question 7

A patient is found to have a defect in the formation of the mesoderm during gastrulation. Which organ system is most likely to be affected?

Accepted Answer

Muscular system

Question 8

Which of the following changes occurs in the maternal body to support fetal development during pregnancy?

Accepted Answer

Increase in respiratory rate and tidal volume

Question 9

During which days after fertilization does implantation of the blastocyst typically occur?

Accepted Answer

Days 7–10

Question 10

Which of the following best explains why only one sperm fertilizes the oocyte, despite the presence of many sperm at the site of fertilization?

Accepted Answer

The oocyte membrane becomes impermeable to other sperm after the first sperm fuses.

Question 11

Which of the following is the correct order of the first stages of cleavage after fertilization?

Accepted Answer

Zygote → 2-cell stage → 4-cell stage → Morula → Blastocyst

Question 12

A blastocyst consists of which of the following components?

Accepted Answer

Inner cell mass, trophoblast, and blastocoele

Question 13

Which of the following equations correctly represents the chromosomal content after fertilization?

Accepted Answer

$$ n + n = 2n $$

Question 14

During which trimester does the fetus experience the most rapid weight gain and the majority of organ systems become fully functional?

Accepted Answer

Third trimester

Question 15

A newborn is found to have a defect in the umbilical vein. Which of the following is most likely to be impaired?

Accepted Answer

Delivery of oxygenated blood from the placenta to the fetus

Question 16

Which of the following best describes the function of the body stalk during early development?

Accepted Answer

It connects the embryo to the chorion and contains blood vessels that carry blood to and from the placenta.

Question 17

Which maternal adaptation is most directly responsible for meeting the increased metabolic demands of the developing fetus?

Accepted Answer

Increase in blood volume

Question 18

A researcher is studying the effects of a toxin that prevents the formation of the syncytiotrophoblast. Which process would be most directly affected?

Accepted Answer

Implantation

Question 19

Which of the following best explains why the first trimester is considered the most dangerous stage of prenatal development?

Accepted Answer

Only about 40 percent of conceptions produce embryos that survive the first trimester.

Question 20

Which of the following is a correct statement about placental circulation?

Accepted Answer

Blood flows from the fetus to the placenta through paired umbilical arteries and returns via a single umbilical vein.

Embryology and Prenatal Development: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard