egg membranes

3
Egg membranes Egg membranes There are 3 types of egg membranes: 1. Primary egg membrane:Formed by the egg itself inside the ovary ; eg. Zona pellucida in mammals and chorion in insects. 2. Secondary egg membrane: Formed by the ovarian tissue before the egg leave the ovary. 3. Tertiary egg membrane: Formed during passage of the egg in the oviduct ; eg. Egg of toad and egg of bird.

Upload: bazyli

Post on 05-Jan-2016

18 views

Category:

Documents


0 download

DESCRIPTION

Egg membranes. There are 3 types of egg membranes: Primary egg membrane:Formed by the egg itself inside the ovary ; eg. Zona pellucida in mammals and chorion in insects. Secondary egg membrane: Formed by the ovarian tissue before the egg leave the ovary. - PowerPoint PPT Presentation

TRANSCRIPT

Page 1: Egg membranes

Egg membranesEgg membranes

There are 3 types of egg membranes:

1. Primary egg membrane:Formed by the egg itself inside the ovary ; eg. Zona pellucida in mammals and chorion in insects.

2. Secondary egg membrane: Formed by the ovarian tissue before the egg leave the ovary.

3. Tertiary egg membrane: Formed during passage of the egg in the oviduct ; eg. Egg of toad and egg of bird.

Page 2: Egg membranes

FertilizationFertilization

Fertilization occurs either external in aquatic animals or internal terrestrial animals .

Steps of fertilization:1. Ovulation.2. Egg transport. 3. Sperm transport. 4. Penetration of the egg.5. Fusion between egg & sperm.6. Prevention of polyspermy. 7. Decondensation of egg and sperm nucleus. 8. Metabolic activation of the egg.

Page 3: Egg membranes