1. biology union of dissimilar reproductive cells: in sexual reproduction, the union of two types of sex cells heterogametes that are dissimilar in size, structure, and function
2. biology alternating of forms of reproduction: the alternation of sexual and asexual reproduction in some species such as aphids in which every other generation is produced from the female with no need for a male
3. botany presence of different flowers on plant: the production on the same plant of two kinds of flower, one bearing both male and female organs and the other bearing only female organs or being asexual
