Animal Reproduction
From budding hydras and parthenogenetic lizards to the hormonal symphony of the human reproductive cycle — how animals create the next generation. Asexual shortcuts, sexual strategies, gametogenesis, fertilization, and how we control fertility.
How Do Animals Reproduce Without Sex?
Asexual reproduction requires no mating and no fusion of gametes — fast and efficient, but produces genetically identical offspring. Mostly used by invertebrates, sessile organisms, and those in stable environments.
Three Types of Asexual Reproduction
Budding
New individuals form from body of parent.
Bud grows by mitotic division, cells differentiate, then breaks away.
Genetically identical clone. Ex: Hydra
Regeneration
Replace damaged tissue OR grow a complete individual from a fragment.
Ex: Echinoderms — severed sea star arm can regenerate a whole new body.
Parthenogenesis
Development from unfertilized eggs.
May determine sex; females can act as males based on hormone cycles.
Ex: Whiptail lizards — all-female species needing mating behavior (not sperm) to trigger egg development.