Question 1

The developing embryo, about 72 hours after fertilization, is called the zygote.

Accepted Answer

A) True 
 B)False  False

Question 2

Briefly describe the two cellular layers that comprise the bilaminar embryonic disc and explain their importance in embryonic development.

Accepted Answer

Cells within the inner cell mass of the blastocyst begin to differentiate into two separate layers approximately nine days after fertilization occurs. These two layers will give rise to all of the cell types of the body. The epiblast will give rise to the three primary germ layers; ectoderm, mesoderm and endoderm. The hypoblast gives rise to the yolk sac, which will develop into part of the digestive tube and tissue around the yolk sac gives rise to the earliest blood cells and blood vessels.

Question 3

The sclerotome will develop into the

Accepted Answer

A)  peritoneum. 
B)  visceral serosa. 
C)  heart. 
D)  vertebrae. 
A)  peritoneum. 
B)  visceral serosa. 
C)  heart. 
D)  vertebrae. D

Question 4

The wall and lining of the gut develop from the mesoderm and , respectively.

Accepted Answer

The answer of The wall and lining of the gut...

Question 5

The neural tube develops from this layer.

Accepted Answer

A)  endoderm 
B)  ectoderm 
C)  mesoderm-somites 
D)  mesoderm-lateral plate 
E)  intermediate mesoderm 
A)  endoderm 
B)  ectoderm 
C)  mesoderm-somites 
D)  mesoderm-lateral plate 
E)  intermediate mesoderm

Question 6

The ability of one cell to influence the development of its neighboring cells is called

Accepted Answer

A)  gastrulation. 
B)  blastulation. 
C)  induction. 
D)  cleavage. 
A)  gastrulation. 
B)  blastulation. 
C)  induction. 
D)  cleavage.

Question 7

Sex can be determined from the genitals.

Accepted Answer

A)  8 weeks (end of embryonic period) 
B)  9-12 weeks (month 3) 
C)  13-16 weeks (month 4) 
D)  17-20 weeks (month 5) 
E)  21-30 weeks (months 6 and 7) 
A)  8 weeks (end of embryonic period) 
B)  9-12 weeks (month 3) 
C)  13-16 weeks (month 4) 
D)  17-20 weeks (month 5) 
E)  21-30 weeks (months 6 and 7)

Question 8

The gonads arise from what embryonic structure?

Accepted Answer

A)  endoderm 
B)  notochord 
C)  intermediate mesoderm 
D)  splanchnic mesoderm 
A)  endoderm 
B)  notochord 
C)  intermediate mesoderm 
D)  splanchnic mesoderm

Question 9

Implantation of the blastocyst on the uterine lining takes about

Accepted Answer

A)  4 weeks. 
B)  1 week. 
C)  3 weeks. 
D)  2 weeks. 
A)  4 weeks. 
B)  1 week. 
C)  3 weeks. 
D)  2 weeks.

Question 10

This is the most common preventable cause of mental retardation in the United States.

Accepted Answer

fetal alco

Question 11

The primary germ layer that ultimately produces the hair, fingernails, and toenails is

Accepted Answer

A)  neural crest. 
B)  mesoderm. 
C)  ectoderm. 
D)  endoderm. 
A)  neural crest. 
B)  mesoderm. 
C)  ectoderm. 
D)  endoderm.

Question 12

is a clinical procedure that provides a genetic profile for a fetus.

Accepted Answer

The answer of is a clinical procedure that provides a...

Question 13

Chemical, physical, or biological agents that can induce birth defects are called

Accepted Answer

A)  mutagens. 
B)  carcinogens. 
C)  free radicals. 
D)  teratogens. 
A)  mutagens. 
B)  carcinogens. 
C)  free radicals. 
D)  teratogens.

Question 14

The urinary bladder is derived from which embryonic layer?

Accepted Answer

A)  mesoderm 
B)  ectoderm 
C)  neural crest 
D)  endoderm 
A)  mesoderm 
B)  ectoderm 
C)  neural crest 
D)  endoderm

Question 15

All major organs are present in rudimentary form.

Accepted Answer

A)  8 weeks (end of embryonic period) 
B)  9-12 weeks (month 3) 
C)  13-16 weeks (month 4) 
D)  17-20 weeks (month 5) 
E)  21-30 weeks (months 6 and 7) 
A)  8 weeks (end of embryonic period) 
B)  9-12 weeks (month 3) 
C)  13-16 weeks (month 4) 
D)  17-20 weeks (month 5) 
E)  21-30 weeks (months 6 and 7)

Question 16

Describe the types of tissues that make up the endoderm, ectoderm, and mesoderm, and explain how these tissues relate to their developmental processes.

Accepted Answer

Both endoderm and ectoderm are epithelia

Question 17

The amniotic sac is derived from the epiblast, while the placenta develops from the

Accepted Answer

A)  neural crest. 
B)  trophoblast. 
C)  hypoblast. 
D)  bilaminar disc. 
A)  neural crest. 
B)  trophoblast. 
C)  hypoblast. 
D)  bilaminar disc.

Question 18

The mesoderm located deep to the neural tube that forms the kidneys and the gonads is the

Accepted Answer

A)  endoderm. 
B)  ectoderm. 
C)  mesoderm-somites. 
D)  mesoderm-lateral plate. 
E)  intermediate mesoderm. 
A)  endoderm. 
B)  ectoderm. 
C)  mesoderm-somites. 
D)  mesoderm-lateral plate. 
E)  intermediate mesoderm.

Question 19

Which characteristic is not true of a blastocyst?

Accepted Answer

A)  It has an inner cell mass and an outer trophoblast. 
B)  It implants into the uterus. 
C)  It develops 24-36 hours after conception. 
D)  It contains a fluid-filled cavity. 
A)  It has an inner cell mass and an outer trophoblast. 
B)  It implants into the uterus. 
C)  It develops 24-36 hours after conception. 
D)  It contains a fluid-filled cavity.

Question 20

As a result of folding, the embryo acquires a tadpole shape by

Accepted Answer

A)  day 9. 
B)  day 24. 
C)  day 12. 
D)  day 15. 
A)  day 9. 
B)  day 24. 
C)  day 12. 
D)  day 15.

Exam 3: Basic Embryology

The developing embryo, about 72 hours after fertilization, is called the zygote.

Briefly describe the two cellular layers that comprise the bilaminar embryonic disc and explain their importance in embryonic development.

The sclerotome will develop into the

The wall and lining of the gut develop from the mesoderm and , respectively.

The neural tube develops from this layer.

The ability of one cell to influence the development of its neighboring cells is called

Sex can be determined from the genitals.

The gonads arise from what embryonic structure?

Implantation of the blastocyst on the uterine lining takes about

This is the most common preventable cause of mental retardation in the United States.

The primary germ layer that ultimately produces the hair, fingernails, and toenails is

is a clinical procedure that provides a genetic profile for a fetus.

Chemical, physical, or biological agents that can induce birth defects are called

The urinary bladder is derived from which embryonic layer?

All major organs are present in rudimentary form.

Describe the types of tissues that make up the endoderm, ectoderm, and mesoderm, and explain how these tissues relate to their developmental processes.

The amniotic sac is derived from the epiblast, while the placenta develops from the

The mesoderm located deep to the neural tube that forms the kidneys and the gonads is the

Which characteristic is not true of a blastocyst?

As a result of folding, the embryo acquires a tadpole shape by

The Human Body: an Orientation

Cells: the Living Units

Tissues

The Integumentary System

Bones and Skeletal Tissues

Bones, Part 1: the Axial Skeleton

Bones, Part 2: the Appendicular Skeleton

Joints

Skeletal Muscle Tissue

Muscles of the Body

Fundamentals of the Nervous System and Nervous Tissue

The Central Nervous System

The Peripheral Nervous System

The Autonomic Nervous System and Visceral Sensory Neurons

The Special Senses

The Endocrine System

Blood

The Heart

Blood Vessels

The Lymphatic and Immune Systems

The Respiratory System

The Digestive System

The Urinary System

The Reproductive System

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