小中大要分清生物学中蛋和卵的关系：
1）蛋：egg，通常指我们平时爱吃的鸡蛋、鸭蛋、鹌鹑蛋的那个蛋，其中包含一个早期的胚胎，不过英文的egg有时也指ovum。an oval object, often with a hard shell, which is produced by female birds and particular reptiles and insects, and contains a baby animal which comes out when it is developed。 2）卵：ovum，也叫卵子，卵细胞egg cell，就是雌配子，通常指单个雌性生殖细胞。The term ovum is usually restricted to the single female sex cell, but the term egg, in its common use to indicate a bird's egg, refers to a more complex structure, only part of which is produced in the ovary of the bird. The ovum of such an egg is a cell swollen with yolk material. The rest of the egg—e.g., the jelly mass surrounding amphibian eggs, and the shell, membranes, and egg white, or albumen, of bird eggs—is not cellular and is secreted around the ovum as it passes down the oviduct. 3）卵母细胞：oocyte，就是形成ovum的那个细胞。A cell from which an egg or ovum develops by meiosis; a female gametocyte。不过，动物的卵母细胞通常在受精后才开始成熟分裂（完成第二次减数分裂），所以所谓的卵子或卵细胞也是卵母细胞。
