NAME:
EVOLUTION IN INVERTEBRATES
DATE:
BLOCK:
PHYLOGENETIC TREE OF THE ANIMAL KINGDOM
•
Phylogenetic trees simplify the evolutionary ________________________ between groups of organisms.
1. ‘Phylo’  __________________ (aka taxonomic groups)
2. ‘Geny’  __________________
•
The phylogenetic tree of animals have several major branches:
1. PROTOSTOMES vs. DEUTEROSTOMES

This division is based on events in early development (________________________)
2. ACOELOMATES vs. PSEUDOCOELOMATES vs. COELOMATES

Mr. Lau
This division is based on the structure of the ________________________________
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Biology 11
EMBRYOLOGY (PROTOSTOMES VS. DEUTEROSTOMES)
Protostomes include:
•
We focus on the female gametes soon after fertilization
o
Immediately after fertilization, _________________ occurs
and the cell grows to 2 cells, then 4 cells, then 8 cells and so
on.
o
@ 8 cells, the new cells can be __________________ in
different ways.

o
•
Deuterostomes include:
_____________________ cleavage vs.
_______________________ cleavage
Cells continue to divide until it forms a
hollow ball called a __________________

One side of this ball becomes
flattened and folds in to form a
____________________ where the
outside cells form the
_____________________ and the
inside cells form the
____________________.

Each type of ‘derm’ will form
different types of tissue
Protostome vs. deuterstome
Mr. Lau
o
‘proto’  ______________ while ‘deutero’
 _________________
o
Stoma  ______________
o
In protostomes, the blastopore becomes the
___________ while in deuterostomes, the
blastopore becomes the ______________.
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Biology 11
BODY CAVITY (ACOELOMATE VS. PSEUDOCOELOMATE VS. COELOMATE)
•
•
•
•
Mr. Lau
During early development, cells also form the ______________________
o
The ________________ is important in the development of the ______________
_______________ (aka __________________ ) which is another major division in the Animal
Kingdom
o
Mesoderm  develops
o
The body cavity is located between the _____________________ tract and the body
_____________.
o
It is a space for the ____________________ of
internal organs
ACOELOMATES  ________ body cavity
o
Filled in with mesoderm
o
Phylum ______________________
PSEUDOCOELOMATES  _______________ body cavity
o
Coelom is only partially lined by mesoderm
o
Phylum ______________________
COELOMATES  __________ body cavity
o
Considered more ‘advanced’
o
A complete mesoderm allows for development of
________________ organs, of _______________
circulatory systems (w/ blood vessels), and more
complexity body plan.
o
Coeolomates include:
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Biology 11