EMBRYOLOGY

Question 1

2 gametes form

Answer 1

zygote

Question 2

weeks 3 - 8 in humans is

Answer 2

embryonic period

Question 3

what causes irreversible structural malformations in foetuses

Answer 3

teratogen

Question 4

what causes changes in the genetic material of cells

Answer 4

mutagen

Question 5

when does spermatogenesis occur

Answer 5

at puberty and continues throughout life

Question 6

when does oogenesis occur

Answer 6

by 28-30 weeks but arrest in prophase until puberty

Question 7

what is the rapid mitotic cell division with no increase in size

Answer 7

cleavage

Question 8

where does the sperm bind to on the oocyte

Answer 8

zona pellucida glycoprotein

Question 9

what makes the zona pellucida impenetrable to other sperm

Answer 9

release of cortical granules by oocyte

Question 10

what is there not in cleavage stage

Answer 10

increase in size

Question 11

morula is how many cells

Answer 11

16+

Question 12

blastocyst is how many cells

Answer 12

200-300 cells

Question 13

what is the trophoblast involved with

Answer 13

facilitates implantation and the formation of the placenta

Question 14

what is placenta previa

Answer 14

placenta lies low in uterus and covers cervix

Question 15

what cell produces hCG

Answer 15

syncytioblast from trophoblast

Question 16

ectoderm is from

Answer 16

skin, hair, nails and nervous system

Question 17

endoderm is from

Answer 17

lining of gut tube, resp tract and bladder and urethra

Question 18

what is the communication between right and left atrial until birth

Answer 18

foramen ovale

Question 19

closure of foramen ovale is caused by

Answer 19

increased left atrium pressure (first breath) and decreasing pressure in right atrium