The new vaccine called Flu Block is made without eggs.

新疫苗名为Flu Block，它的制作不需要卵细。

So an egg cell must be fertilized by a sperm cell to form two full sets of chromosomes.

因此，卵细由精受精才能两套完整的染色体。

In parthenogenesis, an embryo develops from an unfertilized egg cell that doubles its own chromosome count.

在孤雌生殖中，胚胎由未受精的卵细在染色体数目翻倍后发育而来。

Then, they turned the male mouse stem cells into female cells and produced functional egg cells.

然后，他们将雄性老鼠的干细转化为雌性细，并产生功能正常的卵细。

The follicles are small clusters of granulosa and theca cells that protect the developing egg cell.

卵泡是由颗细、卵泡膜细组的小簇，保护发育中的卵细。

Britain's Human Fertilisation and Embryology Authority, however, will allow it in certain cases.

不过英国的人类受精和胚胎学管理局将在某些研究中允许给卵细授精。

Fertilising these eggs for experimentation is forbidden in America.

美国禁止为实验用的卵细受精。

Occasionally, an accident occurs when the egg or sperm cell is forming, creating an extra chromosome number 21.

有时候，在卵细或精时会发生意外，产生出一个多余的21号染色体。

By two years of age, none are left, essentially causing " menopause before menarche" .

在患儿两岁时，已基本没有卵细保留，导致“初潮前的更年期”。

Normally, each egg and sperm cell contains 23 chromosomes, and, when they unite, 23 pairs or 46 in total.

正常情况下，每个卵细和精含有23个染色体，当它们结合在一起时，总共有23对即46个染色体。

Without eggs, the ovaries fail to develop normally, becoming non-functional, fibrous, " streak" ovaries.

没有卵细，卵巢无法正常发育，变无功能的卵巢，被呈条索状纤维组织取代。

While only one egg cell is produced each month.

而每个月只产生一个卵细。

Currently, many women over 45 have to make do with in-vitro fertilisation (IVF) using the egg of a younger woman.

目前，许多45岁以上的妇女只能凑合着用年轻女人的卵细进行体外受精（IVF）。

Researchers have confirmed that women harbour ovarian stem cells, and that these can give rise to new eggs.

研究者们证实，女人拥有卵巢干细，而这种细能为新的卵细的来源。

Then, the adult cell’s nucleus gets stuck into the egg cell essentially replacing the egg cell’s nucleus.

然后，体细的细核卡在卵细中，基本上取代了卵细的细核。

And in its new home in the egg cell, it busts out all those instructions.

在它位于卵细的新家中， 它会执行所有这些指令。

For example, Archaefructus had modified leaves that surrounded its egg cells, forming what's called a carpel.

例如， Archaefructus 改变了包围其卵细的叶，了所谓的心皮。

First, the female needs to be able to create egg cells without stimulation from sperm or mating.

首先，雌性需要能够在没有精刺激或交配的情况下产生卵细。

Using electricity, they transferred the mammary gland cell's nucleus into an egg cell from a second sheep.

他们利用电将乳腺细的细核转移到第二只绵羊的卵细中。

Instead, this fish managed to achieve true self-fertilization, using sperm and egg cells from the same organism.

相反，这种鱼设法实现了真正的自我受精，使用来自同一生物体的精和卵细。