Cnidaria To Cephalopoda

Question 1

what are the characteristics of animals

Answer 1

Eukaryotic
Heterotrophic
No cell walls
Motile (at some point…)
Blastula stage

Question 2

What are Porifera?

Answer 2

sponges
8500 species
Lack true tissue layers
lack symmetry
three groups: Demosphonges (90% of sponges, freshwater and marine), Glass sponges (marine), Calcarea (marine)

Question 3

What is the body plan of Porifera and their cell types?

Answer 3

body plan:
spongocoel (central cavity),
Ostia (pores),
Spicules (skeleton)
Mesohyl (main body wall)

Cell types:
Pinacocytes
Choanocytes
Archeocytes

Question 4

Cnidaria?

Answer 4

Characterized by stinging cells called nematocysts

groups include:
Anthozoans - sea anemones, sea pens, and corals
Scyphozoans - jellyfish
Hydrozoans - Obelia and Hydra
Cubozoans - box jellies

Question 5

What is a tissue?

Answer 5

a group of cells that have a specific function

during development, differentiate from 2-3 layers of the embryo

Question 6

What are the germ layers of tissues?

Answer 6

Ectoderm (epidermal layer of skin)
mesoderm (muscle, bone, kidneys, blood, gonalds, connective tissues)
endoderm (lining of the gut, the liver, and the lungs)

Question 7

What are the different tissue types?

Answer 7

Epithelial
Connective
Muscle
Nervous

Question 8

What are Diploblasts?

Answer 8

Animals with 2 germ layers
Endoderm
Ectoderm

Jellyfish
Corals
Sea Anemones
Comb Jellies

Question 9

What are Triploblast?

Answer 9

animals with 3 germ layers:
Ectoderm
Endoderm
Mesoderm

Protostomes (Mollusks, Annelids, Arthopords)

Deuterostomes echinoderms, chordates)

Question 10

Protostomes development

Answer 10

Eight-cell stage is spiral and determinate
Blastopore becomes the mouth
Schizocoelom formation

Question 11

Deuterostomes development

Answer 11

Eight-cell stage is radial and indeterminate
Blastopore becomes anus
Enterocoelous coelom formation
(ass to mouth)

Question 12

what are the different types of tissue cells?

Answer 12

Epithelial
Connective
Muscle
Nervous

Question 13

What is Epithelial Tissue?

Answer 13

derived from both endoderm and ectoderm

Covers surfaces: both outsides of the body and surfaces of organs

barrier and protective layer

Question 14

what is epithelial tissue classified by:

Answer 14

cell type:
squamous
cuboidal
columnar

number of layers:
simple
stratified
pseudostratified

Question 15

What is Connective Tissue?

Answer 15

Derived from mesoderm

mainly cell products - extracellular matrix (Collagen)

Binds, supports, protects, insulates, stores fuel, transports substances

Question 16

Muscle Tissue

Answer 16

Performs work through contractions ==> Actin & Myosin

Smooth Muscle:
involuntary
GI tract, blood vessels, other vessels

Striated/Skeletal Muscle => Voluntary

Cardiac Muscle:
Involuntary
Only found in the heart

Question 17

Neural Tissue

Answer 17

made up of neurons and glial cells

carry electrical signals via axons to communicate with other cells:
other neurons
muscle cells
secretory cells

Glial Cells: do not carry signals but support neurons

Question 18

What are Amphiuma?

Answer 18

Amphiuma are amphibians; Eels are fish

Longest Salamander Species in the US = Congo Eels

2 pairs of diminutive legs

Vicious bite but not venomous

Question 19

What are Lophotrochozoans?

Answer 19

one of the protostome groups

bilateral symmetry

Many species possess one or both of:
Trocophore, planktonic larval stage
Lophophore, tuft-like structure that surrounds mouth and helps with feeding

Question 20

What is a Coelom?

Answer 20

a true coelom is a body cavity surrounded by mesodermderived tissue on all sides

Lophotrochozoans may be:
acoelomate (flatworm)
pseudocoelomate (roundworm)
coelomate (earthworm)

Question 21

Rotifera

Answer 21

may be as small as unicellular

corona (crown) of cilia that beat in synchrony to draw in prey

triploblastic pseudocoelomates

Complex internal anatomy:
Full gut for digestion
Strictly asexual reproduction
Beat cilia to move

Additional fun facts:
no gas exchange system
well-developed excretory system

Question 22

Platyhelminthes

Answer 22

flatworms

classes:
turbellaria
Monogenea
Trematoda
Cestoda

Triploblastic acoelomates

2-way digestive tract

Question 23

what is the class Turbellaria?

Answer 23

platyhelminthes

Planaria

Mostly nonparasitic and marine

Predatory or scavengers

Ciliated body surface

Question 24

What is the class Trematoda?

Answer 24

a platyhelminthes

flukes

obligate parasites:
mostly vertebrate host
attach to host with suckers

In humans, cause schistosomiasis

Question 25

What is the class Cestoda?

Answer 25

a platyhelminthes

tapeworms

endoparasitic: vertebrate hosts

Scolex with hooks and suckers

main body is called strobila

Consists of proglottids:
body segments
each contains complete male and female reproductive system

No head, no digestive system

gravid proglottids break off to disperse offspring

Question 26

Annelida

Answer 26

Classes:
Polychaetes
Oligochaeta (Earthworms)
Leeches

Coelomates:
fluid-filled coelom allows for hydrostatic movement
circular & longitudinal muscles

metamerism:
each segment contains a separate excretory, nervous, and circulatory system

Setae:
External bristles that grip substrate

Question 27

Mollusca

Answer 27

Mostly marine

Soft bodied

Some have calcium carbonate shell

Visceral mass: collection of internal organs

Mantle - dorsal body wall of all molluscs

Foot - muscle for moving

Question 28

Cephalopoda

Answer 28

octopi, squids, nautiluses, cuttlefish

high-speed ocean predators => arms, tentacles, or fins

Efficient circulatory and gas exchange system:
only mollusks with closed circulatory system
breathe with gills

highly developed nervous systems

Question 29

Dissection Coordinate System

Answer 29

Posterior end
Anterior end
Dorsal side
Ventral side

Distal = further away from the midline

Question 30

Squid Anatomy

Answer 30

arms
tentacles
gills
systemic heart
branchial heart
beak
siphon retractor muscles

Question 31

Echinodermata

Answer 31

Sea stars is an example

Found throughout oceans worldwide
Long lived
Eat with their stomachs
Can regenerate arms

Triploblastic deuterostomes