Z3126328

--Mark Hill 21:58, 5 August 2009 (EST) Where are your answers from Laboratory 1 Assessment?

1. What is the protein that the sperm binds to on the surface?

Zona pellucida protein ZP3 acts as receptor for sperm

2. Name the three stage of follicle development in the ovaries?

1. Primordal follicle

2. Secondary follicle- (Pre-antral follicle)

3. Graffian follicle- (Antral follicle):is the mature follicle

What factor do the synctiotrophoblast cells secrete to support the ongoing pregnancy?

hCG(Human Chorionic Gonadotropin)

What does the corpus luteum secrete to prevent continuation of the menstrual cycle?

progesterone, oestrogen

What are the 2 main tissues to be derived from the germ cell layer continuous with the lining of the amniotic sac?

1.ectoderm, which forms nervous system tissue 2.epithelium of epidermis --Jin Lee 13:53, 12 August 2009 (EST)

1. What period of human development (in weeks) do the 23 Carnegie stages over?

Appoximately 8 to 9 weeks.

2. What part of the somite will contribute to the vertebral column?

Sclerotome of somite contributes to the formation of axial vertebral column.

SomiteinVertebralColumn

3. At what Carnegie stage does the human neural tube normally completely close?

Human neural tube normally completely close at Carnegie stage 13(appox.4 weeks).

--Jin Lee 13:16, 20 August 2009 (EST)