lec 6

Question 1

phylum porifera species richness marine and freshwater

Answer 1

freshwater 200 species
marine 9000

Question 2

phylum Porifera vs rest of metazoa

Answer 2

-show least cellular differentiation and integration of all metazoa
-lack cross striated ciliary rootlets
-almost all sponge adults are sessile

Question 3

what symmetry do sponges have

Answer 3

no clear axes of symmetry

Question 4

Ponifera water canal system components

Answer 4

ostia
oscula or osculum
spongeocoel

Question 5

ostia

Answer 5

one or a few large incurrent pores

Question 6

oscula, osculum

Answer 6

few or one large excurrent pores

Question 7

spongocoel

Answer 7

spacious water filled central cavity
nota true coelom

Question 8

chonanocytes

Answer 8

flagellated cells that water flows through

Question 9

non cellular filler material

Answer 9

mesohyl

Question 10

internal skeleton of ponifera

Answer 10

made of calcareous or silicious spicules or collagenous spongin( or both)

Question 11

cells relatively autonomous and show

Answer 11

totipotency or pluripotency

Question 12

totipency and pluripotency

Answer 12

capacity to transport into all (totipotency) or most cell types (pluripotency)

Question 13

what are the two major growth forms of sponges

Answer 13

upright and encrusting

Question 14

3 body plans in sponges

Answer 14

ascon

sycon

leucon

Question 15

ascon type

Answer 15

single flagellated pumping cavity(spongocoel)

Question 16

sycon type

Answer 16

many flagellated canals connected to spongocoel

Question 17

leucon type

Answer 17

many flagellated chambers connected by non flagellated canals

Question 18

all 3 body plans occur in class

Answer 18

calcarea

Question 19

flat cells that form outer body covering

Answer 19

pinacocytes

Question 20

pinacocytes form the

Answer 20

pinacoderm

Question 21

some sponge species, pinacoderm acts like

Answer 21

true’
epithelial tissue

Question 22

archaeocytes
what are they also known as

Answer 22

amoeboid cells that
can transform into any cell type (totipotent)
amoebocytes

Question 23

encircle osculum and
flagellated chambers, can open and close oscula

Answer 23

myocytes

Question 24

tubular cells

Answer 24

porocytes

Question 25

choanocytes

Answer 25

(collar cells) in choanocyte layer punnping and feeding, can transform to sperm

Question 26

hexactinellids unique features

Answer 26

main part of their body becomes syncytial

Question 27

syncytium

Answer 27

-fused multinucleate mass of cystoplasm in common cell membrane -allows electrical signals to travel -analogous to nervous system of other animals

Question 28

skeletal support in sponges

Answer 28

-collagen fibres: are either loosely dispersed in the mesohyl -spongin: sturdy network of large strands -spicules

Question 29

spongin skeletons occur only in some what sponges only have spongin in they skeleton

Answer 29

demospongiae bath sponges

Question 30

what do spicules consist of?

Answer 30

calcium carbonate or silicon

Question 31

Monorhaphis chuni

Answer 31

very long spicule running through centre of its body

Question 32

feeding in sponges

Answer 32

-the choanocytes capture food like choanoflagellates -phagocytized -capture very tiny particles -they form mutualisms or can be predatory

Question 33

what happens w sponge mutualism

Answer 33

-many sponges harbour photosynthetic endosymbionts -sponge privide nitrogen symbionts provide carrbohydrates

Question 34

sponge sneezing

Answer 34

-special non-mobile cilia on osculum lining sense when the water flow is reduced -myocytes contract and "sneeze" water and blockage out

Question 35

what happens if osculum removed?

Answer 35

no sneeze, why it is thought as analogous to sense organ

Question 36

how do most sponges reproduce?

Answer 36

they are sequentially hermaphroditic -either protandry or protogyny

Question 37

protogyny

Answer 37

female first and then male

Question 38

protandry

Answer 38

male first and female later

Question 39

lecithotrophy

Answer 39

larva swims only briefly before settlement, getting all the food it needs from its yolk supply

Question 40

brooding species

Answer 40

-fertulizatiin internal in the female sponge -larvae are brooded in the female until they to swim via cilia or flagella

Question 41

broadcast spawning species fertilization

Answer 41

occurs in the water

Question 42

sexual reproduction in sponges andwhat transforms to the sperm and eggs

Answer 42

-choanocytes transform into sperm (collar dropped) and eggs -sometimes eggs and sperms released broadcast spawning or free spawning -sometimes eggs retained and sperm broadcasted

Question 43

how many different types of embryogenesis

Answer 43

many however, at least briefly, more than one layer of cells is present

Question 44

do sponges reproduce asexually

Answer 44

most species also have asexual reproduction -budding and/or fragmentation

Question 45

Repair and recognition in Porifera

Answer 45

-certain sponges are able to reconstitute their bodies after cells are separated -cell-cell recognition theory inspired

Question 46

Freshwater sponges unique features

Answer 46

special resistant structures called gemmules that can withstand freezing and drought

Question 47

Economic uses for sponges

Answer 47

-bath sponge industry -bioprospecting for pharmaceutical chemicals because of their antimicrobial, antiviral chemical defences

Question 48

Jurassic Period glass sponges

Answer 48

glass sponge reefs were once thought to have disappeared

Question 49

class calcarea

Answer 49

the calcareous sponges

Question 50

Class Hexactinellida

Answer 50

glass sponges

Question 51

Class Demospongiae

Answer 51

most species-rich only class that includes freshwater spp.

Question 52

Class Homoscleromorpha common name

Answer 52

no common name

Question 53

Calcarea skeleton structure

Answer 53

calcareous spicules with 3 rays, no spongin

Question 54

Demospongiae skeleton structure

Answer 54

-: silica spicules never 6- rayed, some have spongin + spicules and some only spongin

Question 55

Hexactinellida: skele structure

Answer 55

silica spicules, with 3 or 6 rays, no spongin

Question 56

Homoscleromorpha skeleton structure

Answer 56

: small silica spicules called calthrops that have 4 rays, no spongin