Bio1151b Chapter 21 The Genetic Basis of Development
  1. Multicellular organisms develop from a single-celled         to cells of many different types through cell           , cell                  , and                .
  2. Differences between cells is mainly due to differential gene             , even though different cells share genomic              .
  3. Some cells remain             and can generate a whole organism.
  4. One technique for making         of animals is nuclear                  , which has been used to clone mammals such as Dolly and       Cat.
  5. Animal cloning needs to reverse             changes such as              of histones that affect gene             in early development.
  6. Mammalian       cells can be harvested from the             stage during embryonic development, or from some adult tissues, and can differentiate into several types of specialized cells.
  7. Cell                involves             of genes for tissue-specific proteins, and leads to observable                  .
    • Cytoplasmic               in the cytoplasm of the unfertilized egg regulate the expression of genes in the         during embryonic development.
    • Signal molecules from embryonic cells may also cause transcriptional changes in nearby         cells in a process called            ; an example is the nematode Caenorhabditis elegans.
  8. Cell signaling is also involved in apoptosis. or             cell death, which is essential for morphogenesis of digits as well as immune reponses in vertebrates.