Chapter 29 Development

Question 1

Zygote

Answer 1

A cell that results from the infusion of the ovum and sperm.

Question 2

Female

Answer 2

A zygote whose genotype is XX will develop into a female.

Question 3

Male

Answer 3

A zygote whose genotype is XY will develop into a male.

Question 4

Cleavage

Answer 4

Process of cell division that divides the cytoplasm of the zygote.

Question 5

Morula

Answer 5

A solid ball of cells likened to a mulberry.

Question 6

Blastomere

Answer 6

The almost identical cells produced by early cleavage division.

Question 7

Identical twins(non zygotic twins)

Answer 7

Occurs when blastomeres separate.

Question 8

Fraternal twins(dizygotic twins)

Answer 8

Results from 2 different ova.

Question 9

Blastocyst

Answer 9

Hollow ball of cells

Inner cell mass of the blastocyst forms the embryo

Question 10

Blastocoele

Answer 10

The hollow cavity of the blastocyst.

Question 11

Trophoblast

Answer 11

Outer layer of the blastocyst that can penetrate the endometrium; it allows diffusion of nutrients to the embryo; under the influence of the trophoblast, maternal blood vessels in the endometrium breakdown and form lacunae(spaces).

Question 12

Granulation

Answer 12

Formation of the 3 germ layers

Question 13

Ectoderm

Answer 13

Outermost germ layer that gives rise to nervous tissue and epidermis.

Ex: skin cells of epidermis, neuron cells, pigment cells.

Question 14

Mesoderm

Answer 14

Middle germ layer that gives rise to muscle tissue and connective.

Ex: cardiac muscle cells, skeletal muscle cells, tubules cells of the kidneys, RBC, smooth muscle cells in guts.

Question 15

Endoderm

Answer 15

Innermost germ layer that gives rise to glands, and epithelial tissue.

Ex: lung cells, thyroid cells, and digestive cells.