BSC 116 Lecture Notes - Lecture 3: Sarcomere, Paleozoic, Aposematism
23 Aug 2016
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Document Summary
Inductive reasoning: extrapolating from observation to a generalization. Deductive reasoning: use a generalization to explain particular cases. Variation in reproductive modes among animals: sexual vs. asexual reproduction, gonochoristic vs. hermaphroditic, internal vs. external fertilization. Human gametogenesis and hormonal regulation: spermatogenesis in males: constant, oogenesis in females: cyclic. Sexual reproduction fusion of haploid (n) gametes (sperm and egg) to form diploid (2n) zygote: what about asexual reproduction. Gonochoristic separate male and female sexes: what about hermaphroditic species. Internal fertilization gametes mingle in the female"s reproductive tract: what about external fertilization. Asexual reproduction new individuals without sexual intercourse (meiosis) Fission one individual splits into 2 of similar size. Budding in which one individual grows from another. Parthenogenesis offspring develop from unfertilized eggs. Presents a paradox: if each female produces 2 offspring then a population without sex doubles every generation, population with males constant, asexual populations should quickly replace sexual populations by natural selection.
