BIO 182 Lecture Notes - Lecture 21: Internal Fertilization, Neuroglia, Sensory Neuron
Document Summary
Modes of asexual reproduction: fragmentation break off and regenerate, budding daughter cells, binary fission budding in bacteria, parthenogenesis reproduction without fertilization. Modes of sexual reproduction: external fertilization probably came first, internal fertilization helps protect the fertilized egg during development r-strategists, many offspring with little parenting, most common in variable environments. K-strategists: few offspring with lots of parenting, most common in stable environments. Some organisms can switch between asexual and sexual reproduction: more offspring from asexual, stable environment doesn"t need to introduce genetic variation so asexual reproduction works just fine. Amniotic egg allows development in water without actually being in water. Gravity is stronger on land so land animals need stronger bones and muscles. Lung fish transitional form with lungs. Lobe-finned fish transition with muscles in fins. Themes: multi-cellular with no cell wall, heterotrophic, motility, sense and response, growth and development, internal regulation. Sensory neuron responds to the environment. All animals have a nervous system except sponges.
