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Question 1

Prenatal development is commonly described in terms of

Answer 1

trimesters

Question 2

Trimester break the 9 months of pregnancy into 3-month segments. What are those semesters

Answer 2

First trimester (weeks 1 to 13)

Second trimester (weeks 13 to 25)

Third trimester (weeks 25 to 38)

Question 3

The first trimester is broken up into 3 developmental periods. What are they?

Answer 3

Germinal period (conception through week 2)

Embryonic period (weeks 3 through 8): starts when implantation is complete

Fetal period (weeks 9 through 38)( beginning of third month until birth)

Question 4

Toward the end of the first week, the dividing cells have developed into a blastula which is

Answer 4

a ball of cells around a fluid-filled center—that has made its way to the uterus.

Question 5

the process of differentiation;

Answer 5

they start separating into groups according to their future function.

Question 6

What are the 2 different twin types and list the differences

Answer 6

Monozygotic (Identical) Twins-they develop from the same fertilized zygote, they have the same genes:

Dizygotic (Fraternal) Twins: two ova are released simultaneously and each unites with a different sperm,

Question 7

What developes during the embryonic period?

Answer 7

Supportive structures(placenta, umbilical cord, amniotic sac, and amniotic fluid) and embryonic disk

Question 8

During the embryonic period, the embryonic disk grows and develops rapidly. Immediately after implantation, it develops into three distinct layers:

Answer 8

Ectoderm-outer layer
Mesoderm-middle layer
Endoderm-inner layer

Question 9

Miscarriages, technically called_____ccur primarily during the______

Answer 9

spontaneous abortions, first trimester (12-13 weeks)

Question 10

miscarriages after 20 weeks are

Answer 10

rare