Exam 3 - Animals

Chapters 27 and 33

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?

1. Symmetry
2. Number of germ layers
3. Origin of the mouth and anus
4. 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