BIOL 150B Lecture Notes - Choanocyte, Arthropod, Swiss Army Knife
17 Dec 2013
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Introduction to animal diversity reading: chapter 18, p. 383 (homeotic genes); chapter. 457-459 (homeoboxes and hox genes); chapter 25, pp. What are animals: animals are multicellular, heterotrophic eukaryotes. Animals ingest other organisms or organic debris: animal cells are not surrounded by cell walls, animals have intercellular junctions found in no other group of organisms, animals have nervous tissue and muscle tissue. 32. 2 note the evident polarity in the gastrula stage one end is different from the other. How might the polarity in the multicellular gastrula have its origin in the unicellular zygote: almost all animals have hox genes, which contain homeoboxes and which are homeotic in function. Hox genes function during development to specify features of the animal"s body plan. homeobox homeotic gene. Hox genes encode regulators of the transcription of other genes, thereby turning on or off genes whose products build body parts during development. Variation in hox gene activity can therefore lead to variation in animal body plan.
