Fertilization

Question 1

Steps of Fertilization: Part 2

Answer 1

• Metabolic activation of the egg
• Decondensation of the sperm egg
• Completion of Egg meiosis
• Dev and fusion of Male and Female pronuclei

Question 2

A pronucleus carries a _____ set of Chromosomes.

Answer 2

Haploid

Question 3

Menstrual age is _______ than Fertilization age

Answer 3

2 weeks greater

Question 4

Ion interactions in the Acrosomal Rxn

Answer 4

Influx:

• Ca2+
• Na+

Efflux:
- Hydrogen

• Leads to an INCREASE in Acidity

Question 5

Fast Block of Polyspermy

Answer 5

• Rapid depolarization of Egg plasmalemma

- Temporarily prevents Polyspermy and allows time for the egg to establish the slow block

Question 6

Steps of Fertilization: Part 1

Answer 6

• Penetration of Corona Radiata
• Attachment to Zona Pellucida
• Acrosomal rxn and PENETRATION of ZP
• Binding and Fusion of Sperm and Egg

Question 7

Fertilization age

Answer 7

Dates age of embryo from the time of FERTILIZATION

Question 8

Purpose of Capacitation?

Answer 8

• Req for Sperm to undergo Acrosomal rxn
• Binds of sperm to tubal epithelium
• Req binding Sperm to tubal Epithelium

Question 9

What Enzyme is the most important enzyme involved in the Penetration of the ZONA PELLUCIDA?

Answer 9

ACROSIN

Question 10

Acrosin Characteristics

Answer 10

• Serine Protease
• Not released from the acrosome
• DIgests a small hole in the ZP and assists in penetration

Question 11

What helps the sperm to penetrate the Corona Radiata?

Answer 11

• Hyaluronidase

- Swimming movements of the sperm

Question 12

Menstrual age

Answer 12

• Dates age of embryo from Start of mother’s Last MENSTRUAL period.

Question 13

Capacitation Involves what?

Answer 13

• Removal of CHOLESTEROL from Sperm Surface

- Removal of GLYCOPROTEINS (from Epididymis)

Question 14

What is one of the main factors in having a successful in Vitro Fertilization?

Answer 14

Mature Egg

Question 15

Tanning

Answer 15

• The release of cortical granules from the Dark Bodies

- Causes the egg to have a darker appearance

Question 16

ZP3

Answer 16

• One of the Four glycoproteins that make up ZP

- Stimulates Acrosomal rxn in Mammals

Question 17

Pronucleus

Answer 17

• Nuclear material of the head of the Spermatozoan or Oocyte after penetration of sperm cell
• Male pronucleus consists of Decondensed nuclear material

Question 18

What enzyme allows the Sperm to penetrate the corona radiata?

Answer 18

Hyaluronidase

Question 19

Zygote

Answer 19

• The SINGLE felled stage when the male and female pronucleus have FUSED
• Diploid

Question 20

The pregnancy dating systems

Answer 20

1. Fertilization age

2. Menstrual age

Question 21

Steps of Fertilization: Final Part l

Answer 21

• Metabolic activation of egg
• DECONDENSATION of Sperm Nucleus
• Completion of meiosis in Oocyte
• Organization of the first MITOTIC Spindle

Question 22

Blocks of Polyspermy

Answer 22

• Fast Block

- Slow Block

Question 23

What 3 ingredients are needed for a successful In Vitro fertilization

Answer 23

1. Mature Egg
2. Normal Spermatozoa
3. Appropriate Culture environment

Question 24

Slow Block of Polyspermy

Answer 24

• The release of Polysachh from the cortical granules located under the Plasmalemma of the egg
• Increases Width of the space

Question 25

What is responsible for the attachment for the sperm to the ZP?

Answer 25

ZP3 protein

Question 26

What is the only thing that enters the egg from the Sperm?

Answer 26

• Sperm NUCLEUS

- Centrioles