Ch. 47 Part I: Embryology

Question 1

Fertilization

Answer 1

the formation of a diploid zygote from a haploid egg and sperm

Question 2

Syngamy

Answer 2

part of fertilization where two cells or nuclei fuse during reproduction

• fertilization reactions
• chemotaxis
• receptor blinding
• block to polyspermy ==> 1) fast block (~1min) or 2) slow block

Question 3

Acrosomal reaction

Answer 3

• hydrolytic enzymes released from the acrosome make a hole in the jelly coat
• growing actin filaments form the acrosomal process, which protrudes from the sperm head and penetrated the jelly coat
• proteins on the surface of the acrosomal process bind to receptors in the egg plasma membrane

Question 4

Acrosome

Answer 4

• a specialized vesicle at the tip of the sperm

- released hydrolytic enzymes

Question 5

Cortical reaction

Answer 5

• cortical granules in the egg fuse with the plasma membrane
• the secreted contents clip off sperm-binding receptors and cause the fertilization envelope to form
• this acts as a slow block to polyspermy