embryological development

Question 1

zygote

Answer 1

a fertilized ovum which is diploid

Question 2

cleavage divisions

Answer 2

Mitotic divisions of the zygote to increase the number and surface area of cells in a pre embryo (2 cell, 4 cell, 8 cell, etc.)

Question 3

Morula

Answer 3

A berry shaped cluster of pre embryonic cells produced from cleavage divisions.

Question 4

Blastocyst

Answer 4

A fluid filled sphere of cells formed from the morula which implants in the endometrium (uterus).

Question 5

Inner Cell Mass

Answer 5

A group of cells inside of the blastocyst from which the three primary germ layers will develop.

Question 6

Trophoblast

Answer 6

One of the cells making up the outer wall of the blastocyst which will form the chorion.

Question 7

Chorionic Villi

Answer 7

Finger-like growths of the trophoblasts into the endometrium to form the placenta.

Question 8

Chorion

Answer 8

Outermost embryonic membrane which forms the placenta & produces human chorionic gonadotropin.

Question 9

Amnion

Answer 9

Membrane which surrounds embryo to form the amniotic cavity & produces amniotic fluid.

Question 10

Amniotic Fluid

Answer 10

Protects fetus from trauma & permits free movement without adhesion.

Question 11

Yolk Sack

Answer 11

Provides initial nutrients, supplies earliest RBCs and seeds the gonads with primordial germ cells.

Question 12

Gastrulation

Answer 12

Pre Embryo becomes embryo as three primary germ layers form.