n.卵，卵子，卵细胞

原形：ovum复数：ova

The ovum, also known as an egg, is the female reproductive cell in humans and animals.
After fertilization, the ovum combines with sperm to form a zygote, the first stage of embryonic development.
Ovulation occurs when a mature ovum is released from the ovaries into the fallopian tube, ready for fertilization.
In in vitro fertilization, doctors extract eggs (ovum) from a woman's ovaries for laboratory-based conception.
Many species, including reptiles, birds, and mammals, lay eggs containing fully formed or nearly-formed ovum.
The ovum's outer layer, the zona pellucida, plays a crucial role in sperm recognition and binding.
Ovum donation programs help infertile couples by providing healthy eggs from donors.
An ovum can be stored in a fertility clinic for several years before being used in assisted reproductive technologies.
Some genetic disorders, like Down syndrome, can occur if there's an error during the formation of the ovum.
A successful pregnancy depends on the health and viability of the ovum, as well as the uterine environment.
卵子（ovum）是人类和动物的女性生殖细胞。
受精后，卵子与精子结合形成受精卵，胚胎发育的第一阶段。
排卵是指成熟卵子从卵巢释放到输卵管，准备受精。
在体外受精过程中，医生会从女性卵巢中取出卵子用于实验室受孕。
包括爬行动物、鸟类和哺乳动物在内的许多物种，产下包含完整或接近完整的卵子。
卵子的外层——透明带，在精子识别和结合中起关键作用。
女性捐赠卵子的项目帮助不孕夫妇通过提供健康卵子。
卵子可以在生育诊所储存数年，然后用于辅助生殖技术。
一些遗传疾病，如唐氏综合症，可能在卵子形成过程中出现错误。
胚胎能否成功发育，取决于卵子的健康状况和子宫内环境。