CoachThe reproductive cells of Definition 23.1 bear the general name gametes: the male gamete (sperm cell in animals, the pollen grain’s cell in flowering plants) and the female gamete (the egg cell, in ovary or ovule). Gametes are single cells (Chapter 29), and each is half a beginning: alone, a gamete dies; joined, two make a life.
Examples
Example 54.3 (The variations, sorted)
The old collection files neatly under the core. External against internal fertilization (Proposition 23.6): the meeting place. Oviparous against viviparous (Definition 23.4): the zygote’s lodging. Codfish millions against elephant singletons (Proposition 23.7): the numbers ledger. Pollination by bee or wind (Definition 31.3): the male gamete’s travel service. One mechanism, a catalogue of settings.
Example 54.9 (Two dossiers side by side)
The stickleback (Exercise 23.10): gametes shed in water, external fertilization, eggs in a built nest, dozens, guarded by the father, spring. The cherry: gametes in blossom, internal fertilization down the pollen tube, embryos lodged in seeds inside fruit, thousands, provisioned then abandoned to the birds’ delivery service (Exercise 39.12), timed to April. Same form, any species: the dossier is the theory in use.