The other two or three cells produced are called polar bodies.

This results in the production and extrusion of the second polar body.

The first division results in a small "first polar body" and a much larger daughter cell.

The polar bodies, worthless and non-viable in themselves, are examined.

The daughter cell then divides again to form a small "second polar body" and a larger ovum.

Several studies have suggested that polar body screening for aneuploidy may not be optimal.

The first polar body formed is usually larger than the second one, and often divides into two after its separation from the ovum.

Therefore the formation of the first polar body is an especially important factor in forming a healthy zygote (3).

Polar bodies have no function and eventually deteriorate.

(5) "Is the polar body approach best for pre-implantation genetic screening?"

The authors were unable to predict whether a healthy fetus could result from a polar body twinning.

Polar bodies are nonfunctional and incapable of being fertilized.

When meiosis II has completed, an ootid and another polar body have now been created.

Polar body testing will also be unable to detect post-zygotic errors in an oocyte (5).

(Frequently the first polar body degenerates in many strains of mice.)

The polar bodies will be eliminated.

The pictured oocyte has an extruded polar body at about 12 o'clock indicating its maturity.

Why should scale insects, of all creatures, have obligate chimerism involving activated polar bodies?

Verlinsky's "insight" was that he could analyze the polar body to look for certain genetic defects in the resulting egg.

(1)"Mechanism of the chromosome-induced polar body extrusion in mouse eggs".

The ovum divides again, throwing off another polar body which has the same pattern as the ovum.

The polar body of an n-dimensional unit sphere is itself another unit sphere.

Twinning would occur, in principle, if the egg cell and a polar body were both fertilized by separate sperms.

When meiosis I is completed, one secondary oocyte and one polar body is created.