porifera

Question 1

aquiferous system

Answer 1

• water current channel system
• comprised of choanocytes– unique flagellated cells– that drive water through canals and chambers to the cells responsible for food gathering and gas exchange
• defining trait of poriferan systems

Question 2

ostium

Answer 2

ostium/ostia- incurrent pores (water enters thru)
water moves like this: ostium –> atrium/spongocoel –> osculum

Question 3

spongocoel

Answer 3

spongocoel (atrium)- central cavity (of what??)

Question 4

osculum

Answer 4

osculum/oscula- opening of the spongocoel (water exits thru)

Question 5

filter feeding

Answer 5

characteristic behavior of porifera

Question 6

pinacoderm

Answer 6

pinacoderm- continuous outer covering/outer surface cells on sponge material
- one cell thick
- typically unciliated flattened cells/pavement cells
- pinacoderm can be considered a true epithelium

Question 7

mesohyl

Answer 7

mesohyl- gelatinous cell layer between outer pinacoderm and inner choanoderm- contains skeletal elements and cells
- size varies in different sponges, can be very thick or thin

Question 8

choanoderm

Answer 8

choanoderm- inner surface cell layer
- one cell thick

Question 9

Movement

Answer 9

Sessile
(firmly attached to the substratum (underlying layer/substance/foundation- eg. ocean floor))
- ex: sponges, corals, barnacles

Question 10

pinacocyte

Answer 10

pinacocyte- cells that make up the pinacoderm layer

Question 11

porocyte

Answer 11

porocyte- specialized cell that develops (elongates and rolls to form cylindrical tubes) during embryogeny to make up ostia structures
Passes thru all 3 layers

Question 12

choanocyte

Answer 12

choanocyte- unique flagellated cells that drive water through canals and chambers to the cells (make up the aquiferous system)

Question 13

archeocyte

Answer 13

archeocyte- totipotent (can specialize into ANY cell- unlimited potential, think of the like stem cells for sponges)
- can be used to repair damaged tissue, can be used as gametes, can be used as anything
- mobile- move freely within mesolyl layer to transport nutrients gathered by the choanocytes

Question 14

sclerocyte

Answer 14

sclerocyte- active cells that have many mitochondria, cytoplasmic microfilaments, and small vacuoles
- they are responsible for the production of calcareous and siliceous sponge spicules

Question 15

asconoid

Answer 15

asconoid condition- largely unfolded, simple, and continuous choanoderm, lowest SA:V ratio, aquiferous system not as efficient
Vase-shaped animals

Question 16

syconoid

Answer 16

syconoid condition- choanoderm is folded, spongocoel present, higher SA:V ratio

Question 17

leuconoid

Answer 17

leuconoid condition- choanoderm has become both folded and subdivided into separate flagellated chambers- no spongocoel opening, highest SA:V ratio

Question 18

spicules

Answer 18

skeletal elements composed of calcium carbonate or silicon dioxide

Question 19

spongin fibers

Answer 19

spongin- fibrous supportive collagen produced by spongocytes

Question 20

classes of sponges

Answer 20

calcera
hexactinellida
demospongiae
homoscleromorpha

Question 21

calcera

Answer 21

sponge class type
Calcium carbonate spicules
Asconoid, suncoid, and leuconoid

Question 22

hexactinellida

Answer 22

sponge class type where the skeleton is composed of fused 6-rayed siliceous spicules
ex: glass sponges
have syncytial tissue: one cell with multiple nuclei
No pinacoderm layer

Question 23

demospongiae

Answer 23

sponge class type
90% of sponges, both fresh and salt
- all leuconoid
- often used commercially

Question 24

homoscleromorpha

Answer 24

possibly a sponge class type
Spongin skeleton absent
Spicules similar in size

Question 25

choanoflagellates

Answer 25

protists (recall: unicellular organisms)
- some are colonial (colony-forming)
- some can change morphology and become mobile amoeboid cells

Question 26

hemaphroditic

Answer 26

sexual reproduction in sponges
one sponge can produce both eggs and sperm, although often at separate times

Question 27

gonochoristic

Answer 27

sexual reproduction in sponges
separate sections of the sponge body devoted to producing both eggs and sperm

Question 28

conspecific sperm

Answer 28

sperm w distinctive molecules on the outer surface that label it as sperm of the same species

Question 29

Sponge phylogeny details

Answer 29

Sponges may be a paraphyletic group and may eventually be split into different phyla

Question 30

What do they lack?

Answer 30

Nervous tissue
Muscle

Question 31

Gastrulation

Answer 31

Occurs in some sponges
Embryo transforms epithelium from single layer to multiple layers

Question 32

Tissues

Answer 32

Not always present, very simple if they are

Question 33

Size range

Answer 33

A few mm - 1m

Question 34

Poriferan body wall

Answer 34

Pinacoderm, mesohyl, and choanoderm

Question 35

What is specifically contained inside the mesohyl?

Answer 35

Skeletal embers (spongin fibers and spicules) and amoeboid cells

Question 36

What is a choanocyte’s collar made of?

Answer 36

Microvilli

Question 37

Where are carnivorous sponges found?

Answer 37

Deep sea

Question 38

Anatomy of carnivorous sponges

Answer 38

Stalk and filaments
Filaments are covered in spicules with staple-like shape that capture prey

Question 39

Sexual reproduction- where do gametes come from?

Answer 39

Archeocytes can undergo meiosis to become sperm or ova
Choanocytes can become sperm only

Question 40

Sexual reproduction process

Answer 40

Sperm released into water
Choanocyte on female sponge captures the sperm in the water
Choanocyte becomes a transfer cell
Female broods embryo
Larva released

Question 41

Sponge drug application

Answer 41

Tectitethya crypta
Made the HIV drug AZT (azidothymidine)

Question 42

Sponge defenses

Answer 42

Spicules
Bio active compounds (often produced by symbiotic microbes

Question 43

Poriferans evolved from…

Answer 43

Choanoflagellates!