Question

Examples of plasma membrane like egg

Answer 1

Sperm-egg fusion is a cell-cell membrane fusion event essential for the propagation of sexually reproducing organisms. In gamete fusion, as in other fusion events, such as virus-cell and intracellular vesicle fusion, membrane fusion is a two-step process. Attachment of two membranes through cell-surface molecules is followed by the physical merger of the plasma membrane lipids. Recent progress has demonstrated an essential role for an oocyte tetraspanin, CD9, in mouse sperm-egg fusion, and a specific molecular site crucial for CD9 function has been identified. Absence of glycosylphosphatidylinositol-anchored proteins on the oocyte surface also results in loss of oocyte fusion competence in this gamete. These discoveries provide a strong starting point for the identification of additional proteins that have roles in sperm-egg fusion.

Answer 2

Answer:

Sperm Egg

Explanation:

On the basis of origin, egg- membranes are divided into three parts

(1) Primary egg membrane: Oocyte secretes this membrane Examples: Zona Pellucida, Vitelline membrane etc.

(2) Secondary egg membrane: This is seen outside the primary egg membrane & is secreted by the ovary. Examples: Chorion, corona radiata

(3) Tertiary egg membrane: This is present outside the primarveca membrane uterus or the oviduct. Examples: Jelly coat, Shell & Shell membrane.

Some functions of Egg-membranes are as follows:

1. To provide protection

2. To prevents the egg from dessiciation.

3. To provide buovence to the ambian exis

4. To check polyspermy.