Question 1

The embryonic ________ ultimately form the arms and legs of the adult.

Accepted Answer

The answer of The embryonic ________ ultimately form the arms...

Question 2

Which of the following appears latest in human development?

Accepted Answer

A)  limb buds 
B)  somites 
C)  heart 
D)  separate fingers 
A)  limb buds 
B)  somites 
C)  heart 
D)  separate fingers

Question 3

The dermis of the dorsal body region is derived from somites. However, the dermis of the ventral body region is derived from

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 4

A(n) ________ abortion is one in which the fetus dies and is naturally aborted.

Accepted Answer

The answer of A(n) ________ abortion is one in which...

Question 5

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 6

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

Accepted Answer

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

Question 7

Premature birth is one that occurs 38 weeks after conception.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following is endodermal in origin?

Accepted Answer

A)  liver 
B)  spleen 
C)  blood vessels 
D)  skin 
A)  liver 
B)  spleen 
C)  blood vessels 
D)  skin

Question 9

A primitive characteristic that an adult human retains only in part, but is important in determining bilateral symmetry is the ________.

Accepted Answer

The answer of A primitive characteristic that an adult human...

Question 10

The most common cause of mental retardation in the United States is

Accepted Answer

A)  anencephaly. 
B)  spina bifida. 
C)  fetal alcohol syndrome. 
D)  thalidomide. 
A)  anencephaly. 
B)  spina bifida. 
C)  fetal alcohol syndrome. 
D)  thalidomide.

Question 11

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

Accepted Answer

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

Question 12

In human embryos, the yolk sac is important because it

Accepted Answer

A)  stores yolk. 
B)  gives rise to earliest blood cells and blood vessels. 
C)  stores nitrogenous wastes. 
D)  allows for gas exchange through the placenta. 
A)  stores yolk. 
B)  gives rise to earliest blood cells and blood vessels. 
C)  stores nitrogenous wastes. 
D)  allows for gas exchange through the placenta.

Question 13

________ results when the neural tube fails to close cranially.

Accepted Answer

The answer of ________ results when the neural tube fails...

Question 14

Limbs are complete.

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 15

Define the term teratogen, and explain why exposure to teratogens during the first 8 weeks of pregnancy is particularly dangerous.

Accepted Answer

A teratogen is any chemical, biological,

Question 16

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 17

Mucus-producing glands of the respiratory tract arise 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 18

Most organ systems are fully formed and ready to function in the fetus by the sixth month. Which of the following systems is the exception to this generalization because it takes longer to finish development?

Accepted Answer

A)  the circulatory system 
B)  the respiratory system 
C)  the urinary system 
D)  the integumentary system 
A)  the circulatory system 
B)  the respiratory system 
C)  the urinary system 
D)  the integumentary system

Question 19

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

Question 20

The body's axis of development is determined by the

Accepted Answer

A)  blastomeres. 
B)  epiblast. 
C)  notochord. 
D)  primitive streak. 
A)  blastomeres. 
B)  epiblast. 
C)  notochord. 
D)  primitive streak.

Exam 3: Basic Embryology

The embryonic ________ ultimately form the arms and legs of the adult.

Which of the following appears latest in human development?

The dermis of the dorsal body region is derived from somites. However, the dermis of the ventral body region is derived from

A(n) ________ abortion is one in which the fetus dies and is naturally aborted.

All major organs are present in rudimentary form.

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

Premature birth is one that occurs 38 weeks after conception.

Which of the following is endodermal in origin?

A primitive characteristic that an adult human retains only in part, but is important in determining bilateral symmetry is the ________.

The most common cause of mental retardation in the United States is

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

In human embryos, the yolk sac is important because it

________ results when the neural tube fails to close cranially.

Limbs are complete.

Define the term teratogen, and explain why exposure to teratogens during the first 8 weeks of pregnancy is particularly dangerous.

Sex can be determined from the genitals.

Mucus-producing glands of the respiratory tract arise from this layer.

Most organ systems are fully formed and ready to function in the fetus by the sixth month. Which of the following systems is the exception to this generalization because it takes longer to finish development?

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

The body's axis of development is determined by the

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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