Animals I Flashcards
What kind of life cycle do all animals have?
Diplontic (2n dominant) life cycle
When did the earliest animals arrive?
600 mya
(T/F) All animals are multicellular.
True
(T/F) All animals are chemoheterotrophic.
True
Animals are sister group to __________?
Choanoflagellates
Define gastrulation.
The process in which an undifferentiated blastula develops into an embryo with 2 or 3 tissue layers
(T//F) All animals undergo gastrulation.
False. Only Eumetazoans do.
Name five GENERAL characteristics of animals (remember, these characters are not unique to animals. Other living things may exhibit these traits)
- multicellularity
- oogamy
- chemoheterotrophy
- internal digestion
- movement
Name 2 synapomorphies of animals (unique to animals)
- unique junctions between cells
- Extracellular matrix
(T/F) All Eumetazoans are triploblastic.
False. They can be diploblastic as well.
Name the difference between diploblastic and triploblastic
Triploblastic animals have a mesoderm and a mouth
What does the endoderm give rise to
lining of the digestive tract, respiratory tract, pancreas, and liver
What does to ectoderm give rise to
The nervous system, including eyes and ears, and the epidermal layer of skin
What does the mesoderm give rise to
organs like the heart, blood vessels, muscles, and bones
At the 8 cell stage, name differences in cleavage between Protostomes and Deuterostomes.
Protostomes have spiral and determinate cleavage, while deuterostomes have radial and indeterminate cleavage
Compare the mesoderm between Protostomes and Deuterostomes
Protostomes- schizo. Mesoderm splits into two to form coelom
Deuterostomes- enterocoleous: Folds of archenteron form into a coelom
What happens to the blastopore of a Protostome vs a Deuterostome
In protostomes, the mouth develops from blastopore. In deuterostomes, the anus develops from blastopore.
Name an example of a pseudocoelmate animal.
Roundworms. Rotifers. Nematodes.
Name the 3 groups of Diploblastic animals
Cnetophores, Placazoans, Cnidarians
Sponges have a jelly like ______ between epithelial layers
mesophyl
Sponges food is captured by ________ and digested using ________ cells.
Choanocytes, ameboid
Diploblastic animals have _______ nervous systems called “______ ______”
simple, nerve nets
Why are Cnetophores considered to be more basal than the other two diploblast groups?
Placazoans and Cnidarians have HOX-like genes
(T/F) Cnetophores have HOX-like genes.
False
