Question 1

________ Ensheathed by amnion
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ________ Ensheathed by amnion
A) A
B) B
C)...

Question 2

______ Amnion
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The image shows a section of the human placenta, with the amnion labelled as D. The other labelled structures are the chorion (A), villi (B), decidua (C), and fetal vessels (E).

Question 3

________ Chorionic sac
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ________ Chorionic sac
A) A
B) B
C) C
D)...

Question 4

________ Chorionic villi
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ________ Chorionic villi
A) A
B) B
C) C
D)...

Question 5

________ Vestigial structure
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ________ Vestigial structure
A) A
B) B
C) C
D)...

Question 6

________ Skeleton first shows clearly on radiographs and sonograms
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

The fetal skeleton first shows clearly on radiographs and sonograms at around 16 weeks gestation. At this point, the long bones, vertebrae, and skull are visible.

Question 7

______ Stomodeum
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Stomodeum
A) A
B) B
C) C
D) D
E)...

Question 8

______ Separates the amniotic cavity from the hindgut
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Separates the amniotic cavity from...

Question 9

________ Head constitutes about half of the fetus
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

At the beginning of the fetal period,the head constitutes about half the length of the fetus.Thereafter,there is a relative slowdown in the growth of the head compared with the rest of the body.The large head in early fetuses results from the rapid development of the brain.

Question 10

________ Quickening usually occurs
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

Quickening, which is the first fetal movements felt by the mother, typically occurs around 20 weeks of pregnancy.

Question 11

________ Eyebrows, head hair, and lanugo are first visible
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

The 17- to 20-week period is important for several reasons.Fetal movements are first felt by the mother;vernix caseosa forms and affords protection for the fetal skin;lanugo,head hair,and the eyebrows become visible;and brown fat begins to form.This specialized fat is an important site of heat production.

Question 12

______ Will form the lower jaw
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Will form the lower jaw
A)...

Question 13

______ Second pharyngeal arch
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Second pharyngeal arch
A) A
B) B
C)...

Question 14

________ Sex is first distinguishable externally
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

Sex is first distinguishable during the 8- to 12-week period.At 8 weeks,the external genitalia of males and females appear similar.By the tenth week,it may be possible to differentiate between males and females,but the mature form of the genitalia is not reached until the 12th week.

Question 15

______ Site of blood formation in the early embryo
A) A
B) B
C) C
D) D
E) E

Accepted Answer

A is the yolk sac, which serves as the site of blood formation in the early embryo. B is the allantois, which primarily functions in waste removal and gas exchange. C is the chorion, which aids in gas exchange between the embryo and the surrounding environment. D is the amnion, which encases the embryo in amniotic fluid for protection. E is the placenta, which is responsible for nutrient and waste exchange between the mother and developing embryo/fetus.

Question 16

________ Skin is wrinkled and pink to red
A) 12 weeks
B) 16 weeks
C) 20 weeks
D) 25 weeks
E) 29 weeks

Accepted Answer

During the 21- to 25-week period,the skin usually is wrinkled and pink to red because blood in the capillaries is visible through the thin,transparent skin.During the subsequent 4 weeks,considerable subcutaneous fat forms,smoothing out many of the wrinkles.

Question 17

______ Defect in its formation results in a severe type of spina bifida
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Defect in its formation results...

Question 18

________ Contains umbilical vessels
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The area labeled C is the umbilical cord, which connects the fetus to the placenta and contains umbilical vessels (vein and two arteries) that transport oxygen and nutrients to the fetus and waste products away from it.

Question 19

________ Amniotic sac
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ________ Amniotic sac
A) A
B) B
C) C
D)...

Question 20

______ Gives rise to the upper jaw
A) A
B) B
C) C
D) D
E) E

Accepted Answer

The answer of  ______ Gives rise to the upper...

Quiz 1: Gametogenesis and Fertilization

________ Ensheathed by amnion

______ Amnion

________ Chorionic sac

________ Chorionic villi

________ Vestigial structure

________ Skeleton first shows clearly on radiographs and sonograms

______ Stomodeum

______ Separates the amniotic cavity from the hindgut

________ Head constitutes about half of the fetus

________ Quickening usually occurs

________ Eyebrows, head hair, and lanugo are first visible

______ Will form the lower jaw

______ Second pharyngeal arch

________ Sex is first distinguishable externally

______ Site of blood formation in the early embryo

________ Skin is wrinkled and pink to red

______ Defect in its formation results in a severe type of spina bifida

________ Contains umbilical vessels

________ Amniotic sac

______ Gives rise to the upper jaw