4. Fertilization

Question 1

Blastomere division depends on

Answer 1

Waves of Ca2+, induced breakdown of MPF (maturation promoting factor)

Question 2

Steps fertilization

Answer 2

Chemoattraction, binding and docking
Acrosomal reaction (exocytosis)
Fusion of plasma membrane
Sperm nucleus enters egg cytoplasm

Question 3

Binucleated oocytes

Answer 3

Defects in microtubule dynamics, severly affecting chromosome segregation and resulting in poorly resolved chromatin masses.
Die mostly before reaching maturity.

Question 4

Compaction

Answer 4

Blastomeres start to adhere together more tightly
Cells are more compact, but remain separate
E-cadherin expression appears and causes cells to adhere.

Question 5

Binucleated oocytes

Answer 5

Defects in microtubule dynamics, severly affecting chromosome segregation and resulting in poorly resolved chromatin masses.
Die mostly before reaching maturity.

Question 6

Second calcium wave

Answer 6

Pronucleus movement to generate diploid zygote (conception)

Question 7

Fusion of 2 haploid gametes to form a zygote

Answer 7

Near ampulla-isthmus within a day after ovulation.
Sperm needs to break down corona radiata and zona pelucida (-> achieve cortical granule reaction to prevent polysmery (inactivate receptor and harden zona pelucida)
Interaction of multimeric zona recognition complex.
Induces acrosome to release enzymes

Question 8

16 cell stage compaction

Answer 8

16 cell stage: morula
Cleavage: blastomeres
Cavitation
Hatching
Compaction