At approximately _____ weeks of gestation, lecithin is forming on ...

[ishan]

At approximately _____ weeks of gestation, lecithin is forming on the alveolar surfaces, the eyelids open, and the fetus measures approximately 27 cm crown to rump and weighs approximately 1110 g.
 
  a. 20
  b. 24
  c. 28
  d. 30

Question 2

Between 6 and 10 days after conception, the trophoblast secretes enzymes that enable it to burrow into the endometrium until the entire blastocyst is covered. This is termed implantation.
 
  Tiny projections then develop out of the trophoblast and extend into the endometrium. These projections are referred to as a. Decidua basalis
  b. Decidua capsularis
  c. Decidua vera
  d. Chorionic villi

[eliasc0401]

Answer to Question 1

C
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A These milestones would not be completed by 20 weeks of gestation.
B These milestones in human development will not be completed at 24 weeks of
gestation.
C These are all milestones that occur at 28 weeks.
D These specific milestones will be reached as early as 28 weeks, not 30 weeks of
gestation.

Answer to Question 2

D
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A The deciduas basalis is the portion of the endometrium where the chorionic villi
tap into the maternal blood vessels.
B The deciduas capsularis is the portion of the endometrium that covers the
blastocyst.
C The portion of the endometrium that lines the rest of the uterus is called deciduas
vera.
D These villi are vascular processes that obtain oxygen and nutrients from the
maternal bloodstream and dispose of carbon dioxide and waste products into the
maternal blood.

[ishan]

TYSM

[Dominic]

Excellent