BIO 182 Lecture Notes - Lecture 22: Precocial, Altricial, Ctenophora
Document Summary
What they eat: herbivores eat plants. Need to be able to break down cell wall. Long, complex gut enzymes to break down plant cells: carnivores eat living animals. Shorter gut acid: omnivores eat plants and animals, detritivores eat dead organisms (recyclers) Parasites live in (endo) or on (ecto) host: small, complex lives, don"t normally kill host. Parasitoids plant eggs in or on host: normally kills host, spends significant amount of life with host. Normally in water: fluid feeders, deposit feeders, mass feeders. Life cycles: direct development babies are similar to adults, metamorphosis larva very different from adults. Reproductive trade-offs: dependent until sexual maturity, stable environment more time for parenting, variable environment beneficial to produce more offspring, bird incubation. Altricial helpless when hatched so they need parenting. Precocial longer incubation so hatchlings are more advanced. Parasite life cycle: energy required to defeat defenses of host, need to spread to more hosts which requires energy.
