tutorial: Intro to animals Flashcards
process of growth from fertilization to the formation of a gastrula
- sperm fertilizes the egg
- egg becomes zygote (2n)
- zygote undergoes mitosis (3 times) to form eight-celled stage
- eight-celled stage and cleavage make blastula
- blastula undergoes gastrulation to make gastrula
what structures make up a gastrula
- blastocoel
- endoderm
- ectoderm
- archenteron
- blastophore
radial vs bilateral symmetry
radial
1. similar parts regularly arranged around a central axis
2. NO front, back, left or right
bilateral
1. anatomical parts are arranged on OPPOSITE sides of a median axis
2. ONLY ONE place can divide into two halves
3 main tissue types important during embryonic development
- ectoderm
- endoderm
- mesoderm
ectoderm
outermost germ layer covering the surface of the embryo
what does the ectoderm give rise to
- outer cover of the animal
- sometimes the CNS
endoderm
innermost germ layer that lines the pouch forming during gastrulation (archenteron)
endoderm gives rise to
- lining of digestive tract/cavity
- organs - liver and lungs
mesoderm
fills the space between the ectoderm and endoderm
mesoderm forms the
- coelom
diploblastic vs triploblastic
triploblastic
1. ectoderm, endoderm and mesoderm
2. ALL bilaterians are triploblastic
diploblastic
1. ectoderm and endoderm
example of diploblastic
Cnidarians
example of triploblastic
bilaterians
3 types of coelomates
- pseudocoelomates - body cavity is PARTIALLY lined with mesoderm
- coelomate - body cavity is lined with mesoderm COMPLETELY
- acoelomate - NO body cavity
protosome development
- cleavage = spiral and determinate
- coelom forms from masses of mesoderm splitting
- blastophore is the mouth
deuterostome development
- cleavage = radial and indeterminate
- Coelom Formation: mesoderm buds from wall of archenteron.
- Blastopore Fate: Forms Anus
alimentary vs gastrovascular cavity
alimentary
1. one way digestive tract
2. two holes (mouth and anus)
gastrovascular cavaity
1. open hole (mouth and anus)
2, blind gut/coelenteron
what will this embryo develop into with
SPIRAL CLEAVAGE at the eight-cell stage
earthworm (protostome)
character shared by diverse animals from whales to coral
presence of Hox genes
the incorrect pairing of germ layer with tissue/organ
1. ectoderm - outer covering
2. endoderm - internal digestive tract
3. mesoderm - nervous system
4. mesoderm - muscles
5. endoderm - liver and lungs
3 (mesoderm - nervous system)
the incorrect pairing of germ layer with tissue/organ
1. ectoderm - outer covering
2. endoderm - internal digestive tract
3. mesoderm - nervous system
4. mesoderm - muscles
5. endoderm - liver and lungs
3 (mesoderm - nervous system)
the incorrect pairing of germ layer with tissue/organ
1. ectoderm - outer covering
2. endoderm - internal digestive tract
3. mesoderm - nervous system
4. mesoderm - muscles
5. endoderm - liver and lungs
3 (mesoderm - nervous system)
blastophore is evident in the
gastrula
fungi and arthropods have in common
protective coat of both groups are made from chitin