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What is the significance of the Cambrian explosions?
There was an “explosion” of genetic diversity due to the increased O2 in the atmosphere.
When was the Cambrian explosion?
Approximately 538.8 million years ago
What is common in most animals?
Multicellularity, complex tissue, heterotrophy, active movement, and diversity in size.
How many extinctions have happened on our planet?
At least five
What develops first in protostomes?
Mouth
What is an example of a protostome?
Arthropods, octopus, and flatworms
What develops first in deuterostomes?
Anus
What is an example of a deuterostome?
Humans
What is cleavage?
series of mitotic cell divisions
What is blastula stage?
In between 6-32 cells and is hollow.
Gastrulation is the stage between…
blastula and gastrula
What is the main difference between the blastula and gastrula?
The gastrula has developed a blastopore.
What is A?
Blastocoel
What is B?
Ectoderm
What is C?
Endoderm
What is D?
Archenteron
What is E?
Blastopore
How many germ layers do diploblastic organisms have?
Two
What is an example of a diploblast?
Jelly fish
How many germ layers do triploblastic organisms have?
Three
What is an example of a triploblast?
A human
What are Hox genes responsible?
They are responsible for putting the right number of appendages in the right place.
If the Hox genes fail what is likely to happen?
Too few/many appendages
What are the four traits used to differentiate animals?
Symmetry
Number of germ layers
Origin of the mouth and anus
Body plan and cavities
A sponge is ----, because ----.
Asymmetrical / they lack symmetry
An anemone has ---, because ----.
Radial symmetry / they have symmetry around a central axis
A goat has ---, because ----.
Bilateral symmetry / because there right and left sides.
Endoderm
Inner lining of most digestive tract organs
Mesoderm
all muscle, bone, cartilage, blood, most other visceral organs
Ectoderm
outer epithelium of body surface, central nervous system
Coelom
Body cavity
Acoelomates
Lack of a coelom
Pseudocoelomates
False coelom
coelomates (eucoelomates)
Has a coelom
What is the cleavage pattern of a protostomes?
determinate spiral cleavage
What is the cleavage pattern of a deuterostomes?
indeterminate radial cleavage
sagittal plane
divides the body into right and left portions
midsagittal plane
Divides the body exactly in the middle, making two equal right and left halves
frontal plane
separates the front from the back
transverse plane
divides the animal into upper and lower portions.
What two cavities make up the dorsal cavity?
cranial and vertebral (or spinal)
What two cavities make up the ventral cavity?
thoracic or abdominopelvic cavity
what are the two limitations on size and shape?
Gravity and drag
What has the largest surface area to Volume ratio?
A
Endotherms
Warm blooded animals
Ectotherms
cold blooded animals
Which animals spend more energy on heating themselves?
Endotherms
What are the two different types of epithilial tissue?
Stratified and simple
Were can you find epithelial tissue?
Line cavities, open spaces, and surfaces
Where can you find connective tissue
Connect tissues together, provide support
What is the purpose of muscular tissue?
Movement
What are the three types of muscular tissue?
Skeletal, cardiac, and smooth
What is the purpose of neurons?
Generate and send electrical signals
Negative Feedback Loop --- the direction of change.
reverses
Positive Feedback Loop --- the direction of change.
strengthens
Note
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