Biology

Chapter 14 Mendel and the Gene Idea Lecture Outline Overview: Drawing from the Deck of Genes The ?blending? hypothesis popular 1800s This hypothesis proposes that genetic material contributed by each parent mixes in a manner analogous to the way blue and yellow paints blend to make green. With blending inheritance, a freely mating population will eventually give rise to a uniform population of individuals. Everyday observations and the results of breeding experiments tell us that heritable traits do not blend to become uniform. An alternative model: the ?particulate? inheritance proposes that parents pass on discrete heritable units, genes, that retain their separate identities in offspring. Genes can be sorted and passed on, generation after generation, in undiluted form.

Chapter 12 The Cell Cycle Lecture Outline Overview: The Key Roles of Cell Division The ability of organisms to reproduce their kind is the one characteristic that best distinguishes living things from nonliving matter. The continuity of life is based on the reproduction of cells, or cell division. Cell division functions in reproduction, growth, and repair. The division of a unicellular organism reproduces an entire organism, increasing the population. Cell division on a larger scale can produce progeny for some multicellular organisms. This includes organisms that can grow by cuttings. Cell division enables a multicellular organism to develop from a single fertilized egg or zygote.