meroblastic Type of cleavage in which only the blastodisc undergoes division. 不完全卵裂只有胚盘历经卵裂的过程。
yolk cell A giant syncytial uncleaved cell containing the yolk. It underlies the blastodisc early in development and becomes enveloped by the blastoderm during epiboly. 卵黄细胞庞大的融合不分裂细胞，包含卵黄的。发育早期它在胚盘之下，外包时期变成藉由囊胚包裹。
vegetal pole Opposite to the animal pole on the egg. Later in embryonic development corresponds to the point on the yolk cell furthest from the developing blastodisc. 植物极在卵上位于动物极对面。稍后胚胎发育在卵黄细胞上与发展中的胚盘最远的一点。
