Fertilization, Blastulation, Implantation

Question 1

Where does fertilization occur?

Answer 1

in the ampulla of the fallopian tube

Question 2

What are the 2 processes that the sperm undergoes during fertilization?

Answer 2

1. Capacitation - acrosome loses its glycoprotein coat via hormone signals
2. **Acrosome Reaction **- acrosome enzymes including hyaluronidase break the ZP

Question 3

What are the 2 processes that the oocyte undergoes during fertilization?

Answer 3

1. **Zona Reaction **- after sperm head touches, ZP changes to keep out other sperm
2. Oocyte Reaction - 2nd meiosis finishes (creating 1 oocyte and 3 polar bodies) and the membranes of the 2 gametes fuse to create the spermovium

Question 4

What is the name of the cell made of the male and female gametes?

Answer 4

zygote

Question 5

What is the process of zygote division called?

Answer 5

cleavage

Question 6

What is the zygote called by the time it has divided 4 times?

Answer 6

**morula **once it is 16 cells

Question 7

What is the morula called after it reaches the uterus, its cells differentiate into 2 types and a cavity is formed?

Answer 7

blastocyst

Question 8

What process happens to the blastocyst when the pressure within it increases?

Answer 8

hatching - blastocyst comes out of the zona pellucida, which degenerates and disappears

Question 9

What are the 2 types of cells in the blastocyst?

Answer 9

trophoblast - around outside

**embryoblasts ** - clustered inside to one side of cavity within trophoblast ring

Question 10

What is the cavity in the blastocsyt called?

Answer 10

blastocyst cavity

Question 11

What process occurs when the blastocyst reaches maturity?

Where, how and with what orientation?

Answer 11

implantation

• in the uterus, wherever maturity is reached, but ideally not too near cervical opening
• trophoblast cells protrude up into the uterine wall with the embryoblast side towards the wall

Question 12

What is the cell layer of the uterine wall that blastocyst cells protrude into?

Answer 12

decidua cells

Question 13

What are the 6 main phases of fertilization?

Answer 13

Pork Pies Feed Many Old Zookeepers

1. Passage (of sperm thru CR via hyaluronidase)
2. Penetration (of ZP via acrosin)
3. Fusion (of sperm and egg membranes)
4. Meiosis II (oocyte pronucleus + polar body)
5. Oootid Formation (sperm pronucleus forms)
6. Zygote Formation (pronuclie fuse, clv spindle)

Question 14

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