Question 1

Which of the following best describes the sequence of early vertebrate development from fertilization to organogenesis?

Accepted Answer

Fertilization → Cleavage → Gastrulation → Organogenesis

Question 2

During fertilization in sea urchins, which process provides the fast block to polyspermy, and what is its mechanism?

Accepted Answer

Acrosomal reaction; depolarization of the egg membrane

Question 3

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

Accepted Answer

Ectoderm

Question 4

A genetic mutation prevents the formation of the allantois in a bird embryo. Which of the following is the most likely consequence?

Accepted Answer

The embryo will be unable to store nitrogenous wastes efficiently.

Question 5

Which extraembryonic membrane is primarily responsible for gas exchange in amniotes and also contributes to the formation of the placenta in mammals?

Accepted Answer

Chorion

Question 6

In mammals, what is the main function of the amnion during embryonic development?

Accepted Answer

Secretes a clear fluid that cushions and protects the embryo

Question 7

Which of the following best explains why the mother’s and fetus’s blood do not mix directly in the placenta?

Accepted Answer

A membrane between the chorionic villi and endometrium separates the blood supplies.

Question 8

A researcher observes a vertebrate embryo at the stage where the neural tube is forming. Which process is this embryo undergoing?

Accepted Answer

Organogenesis

Question 9

Which of the following is a correct match between an embryonic germ layer and a structure it forms?

Accepted Answer

Endoderm – Respiratory tract lining

Question 10

If a mutation disrupts the formation of the neural tube during human development, which system is most likely to be affected?

Accepted Answer

Central nervous system

Question 11

Which of the following best describes the role of calcium ions during the cortical reaction in fertilization?

Accepted Answer

They trigger the hardening of the vitelline layer, forming the fertilization envelope.

Question 12

During which stage of human development are the brain and lungs primarily completing their development?

Accepted Answer

Third trimester

Question 13

A human embryo is observed with limb buds, a heart, and a notochord, but is not yet called a fetus. In which trimester is this embryo?

Accepted Answer

First trimester

Question 14

Which structure in placental mammals develops from the chorion and the endometrium and is essential for nutrient and gas exchange?

Accepted Answer

Placenta

Question 15

A vertebrate embryo is at the blastula stage. What is the next major developmental process it will undergo?

Accepted Answer

Gastrulation

Question 16

Which of the following correctly describes the function of the yolk sac in oviparous animals?

Accepted Answer

It provides nutrients to the developing embryo.

Question 17

If the chorion fails to develop properly in a placental mammal, which of the following is the most likely result?

Accepted Answer

The embryo will not be able to exchange gases and nutrients with the mother.

Question 18

Which process is responsible for the formation of a three-layered embryo from a blastula?

Accepted Answer

Gastrulation

Question 19

In vertebrate development, which structure is the first to form during organogenesis?

Accepted Answer

Notochord and nervous system

Question 20

A patient is born with a defect in the fusion of the neural tube. Which developmental process was most likely disrupted?

Accepted Answer

Organogenesis

Vertebrate Development: From Fertilization to Human Gestation

Study Guide - Practice Questions