Card Set Information
Characteristics of Animals
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
If animals lack cell walls, how are their bodies held together?
with extracellular proteins, such as collagen
What are the 2 unique tissues found in animals and what is their function?
-nervous tissue- impulse conduction
-muscle tissue- movement
How do these heterotrophic animals eat?
they ingest organisms or organic material that is decomposing
A zygote undergoes ___________ that leads to the formation of a blastula. (define blastula)
-cleavage; (blastula- hollow ball of cells)
-a succesion of mitotic cell divisions leading to the formation of a multicellular blastula
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
Some animals develop directly through transient stages into adults; others have ________ stages. Give examples. What do these ________ undergo to transform into an adult?
: frog & tadpole)
-they undergo metamorphosis
What are Hox genes and what do they do?
-regulate expression of other genes and help transform zygote to animal of specific form
(they are similar in animal groups)
What are the 3 types of muscle tissue?
smooth, skeletal, and cardiac
In sexual reproduction of animals, the sperm is ______________ while the egg is ____________.
- small and flagellated (motile) ------larger and nonmotile