Final Exam - Development

Question 1

embryo

Answer 1

multicellular eukaryotic cell during the first two months

Question 2

morula

Answer 2

forms 3 to 4 days after contraception

Question 3

blastula/blastocyst

Answer 3

forms around day 5 - hollow ball of cells

Question 4

trophoblast

Answer 4

forms outer layer of cells of the blastocyst and forms the chorion, and HCG to maintian pregnancy

Question 5

chorion

Answer 5

produces HCG to maintain pregnancy

Question 6

amnion

Answer 6

membrane formed around embryo, fills with amniotic fluid and expands for protective enviornment for embryo

Question 7

allantosis

Answer 7

helps embryo exchange gases and handle liquid waste forms umbilical cord

Question 8

yolk sac

Answer 8

nutrition, sac attached to embryo

Question 9

human chorionic gonadotropin (HCG)

Answer 9

maintains pregnancy

Question 10

gastrulation

Answer 10

• inward cell movement which occurs during the third week

- forms the 3 germ layers

Question 11

ectoderm

Answer 11

-skin and nervous tissue

Question 12

endoderm

Answer 12

-digestive and respiratory system

Question 13

mesoderm

Answer 13

muscles, skeletal, circulatory, and urogenetial system

Question 14

organogenesis

Answer 14

• weeks 3 to 8
• beginning of organ development
• homebox(HOX) genes which are transciption factors that control the order in which embryonic genes are turned on
• sexual development begins

Question 15

HOX genes (homebox)

Answer 15

genes that are transciption factors that control the order in which embryonic genes are turned on
-example-neural tube development

Question 16

bi-potentiality

Answer 16

ability to develop in two ways male or female or hemophrodatism

Question 17

hermaphrodatism

Answer 17

having characteristics of both sexes

Question 18

testicular feminization or androgen insensitvity

Answer 18

lacks androgen receptors

• phenotype-female genetalia
• has undesended testes so no ovary
• external vaginal opening but blind pouch
• testerone converts to estrogen

Question 19

psuedohermaphrositism

Answer 19

• lacks alpha-5 reductase so testerone cannot easily be converted
• has wolfian system but has phenotype of a female
• overtime lengthing of urethra at puberty and scrotal sac
• undesended testes