1. What are the 5 characteristics of animals?
    • -they are multicellular, heterotrophic eukaryotes
    • -lack cell walls
    • -have two unique tissues: nervous tissue & muscle tissue
    • -reproduce sexually; diploid stage dominates life cycle
    • -have hox genes
  2. If animals lack cell walls, how are their bodies held together?
    with extracellular proteins, such as collagen
  3. What are the 2 unique tissues found in animals and what is their function?
    • -nervous tissue- impulse conduction
    • -muscle tissue- movement
  4. How do these heterotrophic animals eat?
    they ingest organisms or organic material that is decomposing
  5. A zygote undergoes ___________ that leads to the formation of a blastula. (define blastula)
    -cleavage; (blastula- hollow ball of cells)
  6. Define cleavage.
    -a succesion of mitotic cell divisions leading to the formation of a multicellular blastula
  7. A blastula will undergo _______ in which some cells migrate inward to form 3 tissue layers which are:_______. The embryo will now be called a _______.
    -gastrulation (ectoderm-outer, endoderm-inner, mesoderm-middle) -gastrula
  8. Some animals develop directly through transient stages into adults; others have ________ stages. Give examples. What do these ________ undergo to transform into an adult?
    • -larval (ex: frog & tadpole)
    • -they undergo metamorphosis
  9. What are Hox genes and what do they do?
    • - homeobox
    • -regulate expression of other genes and help transform zygote to animal of specific form
    • (they are similar in animal groups)
  10. What are the 3 types of muscle tissue?
    smooth, skeletal, and cardiac
  11. In sexual reproduction of animals, the sperm is ______________ while the egg is ____________.
    - small and flagellated (motile) ------larger and nonmotile
Card Set
Characteristics of Animals