Topic 21: Porifera And Cnidaria

Question 1

What is phylu porifera? (Sponges)

Answer 1

Basal animals that lack true tissues

Question 2

Sponges are sessile, in what stage are they ot sessile?

Answer 2

The larvae stage (motile)

Question 3

Sponges are known to lack true tissues, what are some examples?

Answer 3

No internal organs, no circulatory system, no nervous system, muscles, etc.

Question 4

What are two structures a sponge is supported by?

Answer 4

Spicules ad spongin

Question 5

What are spicules

Answer 5

tiny needles or rods of silica
or calcium carbonate that maintain the
shape and structure of the sponge.

Question 6

What is spongn?

Answer 6

Fibrous collagen-protein network for support

Question 7

Identify the four simple cell types in a sponge

Answer 7

Choanocytes, amoebocytes, porocytes, and epidermal cells

Question 8

What are choanocytes

Answer 8

Cells that line the inner cavity of the sponhe (spongocoel).
Generates water currents by beating their flagella, capture food particles, deliver nutrients and oxygen to the sponge and remove waste and CO2

Question 9

Ameobocytes

Answer 9

-Found in the mesophyl
-transports nutrients to other cells in the sponge, make skeletal fibres (spicules) and can differentiate into different cell types

Question 10

Epidermal cells

Answer 10

Form te outer layer of the sponge, they consist of tightly packed cells

Question 11

What are porocytes

Answer 11

Tubular cells that make up the pores of a sponge that allow water to flow through

Question 12

What is the mesophyl latyer of the sponge?

Answer 12

A gel-like, non cellular matrix that separates epidermis and choanocyte layers

Question 13

What two cellular ayers does the body of a sponge consist of?

Answer 13

Epidermis and choanocyte layer with a mesophyl layer in between

Question 14

Gel-like substance that provides structural support to the sponge

Answer 14

Mesophyl

Question 15

What does the mesophyl contain?

Answer 15

Amebocytes and skeletal elements (spicules and spongin) deposited by amoebocytes

Question 16

What kind of of feeders are sponges, and what does it mean by their feeding type?

Answer 16

Sponges are suspension feeders
The capture food particles in the water

Question 17

How is water drawn in a sponge?

Answer 17

By beating their choanocyte flagella through pores (ostia) into a cavity (spongocoel) through an opening (osculum)

Question 18

Besides flagella, what do collarcells/choanocytesdo to extract food particles ?

Answer 18

They use a muscus covered microvlli which engulf their food particles via phagocytosis and digested internally or transferred to amoebocytes

Question 19

Most sponges possess both male and female reproductive parts, what is the appropriate term for this?

Answer 19

Hermaphrodites

Question 20

What do sponges lack?

Answer 20

• true tissues
• organ systems
• reproductive systems

Question 21

Gonads

Answer 21

Reproductive organs

Question 22

In sponges, where do the sperm and the egg develop from?

Answer 22

Sperm-modified choanocytes
Eggs- modified ameobocytes

Question 23

Are most sponges able to self-fertilize?

Answer 23

No

Question 24

Is it more common for a sponge to fertilize externally or internally?

Answer 24

Internally

Question 25

In a sponge, what do the zygotes develop into?

Answer 25

Motile ciliated larvae (within the mesophyl)

Question 26

Whar are the two ways that sponges can reproduce asexually?

Answer 26

Fragmentation or budding

Question 27

What simple cell capturres sperm cells and where does it go

Answer 27

Sperm cells are captured by choanocytes after that it goes to the amoebocytes then the mesophyl (where the eggs are)

Question 28

Clade that characterized by the prescence of tissues

Answer 28

Clade eumetazoa

Question 29

Basal eumetasoan phyla

Answer 29

Ctenophora and cnidaria

Question 30

What makes basal eumetozoans more different than the rest of those in the clade?

Answer 30

No centralized nervous system r cephalization

Question 31

what do mmost eumetazoans exhibit?

Answer 31

radial symmetry and are diploblastic

Question 32

what phylum is one of the earliest descendants of eumetazoa?

Answer 32

phylum cnidaria

Question 33

what characterizes cnidarians

Answer 33

simple radially symmetrical dipoblastic body plan

Question 34

what is the body plan of a cnidarian?

Answer 34

sac-like body plan with a central gastrovascular cavity (digestive compartment)

Question 35

what does the opening to the gastrovascular cavity do?

Answer 35

functions as a mouth and anus

Question 36

phylum with tentacles containing stinging cells (cnidocytes)

Answer 36

cnidaria

Question 37

what does the body of the cnidarian phylum have with layers?

Answer 37

their outer layer is derived from the ectoderm and an inner gastrodermis derived from the endoderm

Question 38

how is the epidermis and gastrodermic separated?

Answer 38

by meoglea (middle jelly)

Question 39

what is mesoglea?

Answer 39

a jelly, non-cellular matrix

Question 40

how does gas exhcange occur in cnidarians

Answer 40

diffusion across the epidermis

Question 41

what are the two variations of body plans in the cnidarian phylum?

Answer 41

sessile polyp and a motile medusa

Question 42

a body plan that attatches to substrate, oral end upwards (sea anenome)

Answer 42

sessile polyp

Question 43

bell shaped-body plan that moves freely in water by a hydrostatic skeleton, oral end is downwards

Answer 43

motile-medusa

Question 44

what kind of animals are cnidarians

Answer 44

predators

Question 45

in cnidaria, what are the tentacles armed with?

Answer 45

cnidocytes

Question 46

what are nematocytes

Answer 46

complex organelles in cnidarians that deliver stinging tocins

Question 47

what are the two early clades in cnidarians

Answer 47

clade medusa and clade anthozoa

Question 48

clade that alternate between polyp and medusa form in their life cycle

Answer 48

medusazoa

Question 49

how do medusae reproduce and how are medusae made?

Answer 49

reproduce by sexual reproduction, created by budding from polyps

Question 50

what is the most predominant stage in a jellyfish's life style?

Answer 50

medusa

Question 51

what is the difference in life cycle of scyphozoans and cubozoans

Answer 51

coastal scyphozoans have a shorter polyp stage. oceanic species have no polyp stage

Question 52

clade with sea anenomes and corals

Answer 52

anthozoans

Question 53

clade that only occurs as polyps

Answer 53

anthozoans