Bio 108 - Lecture 17

Question 1

Parazoa Characteristics
Para=
Zoo=

Answer 1

Considered to be basal to all other animals and lack true tissues
Beside
Animal

Question 2

Two Phylums Parazoa belong too

Answer 2

1) Almost all belong to Phylum Porifera

2) Phylum Placozoa, only one species does

Question 3

What Species Belongs to Phylum Placozoa

Answer 3

Trichoplax adharerens

Question 4

Totipotent

Answer 4

cells can transform to do all jobs

Question 5

Phylum Porifera Characteristics
Por=
Fer=

Answer 5

• No tissues or organs
• Structural Support comes from spicules
• Spicules can be calcareous or silicious
• Spongin is tough collagen-protein network for support
  = Pore
  = To bear

Question 6

Two main types of cells in Phylum Porifera

Answer 6

1) Amoebocytes
- Form outside of surface of the sponge
- Carry food to other cells
2) Choanocytes
- Line inside of sponge

Question 7

Mesophyl in Porifera?
Meso=
Hyl=

Answer 7

A gelatinous acellular layer between the outer skin and the choanocyte layer
= middle
= stuff

Question 8

Porifera Eating

Answer 8

Suspension feeding

Food particles are phagocytosed

Question 9

Simultaneous Hermaphrodites vs Sequential

Answer 9

Simultaneous - are male and female at the same time

Sequential - are first one sex, then change to be the other

Question 10

Behaviour of Zygote in Porifera

Answer 10

1) Zygote is retained until it develops into ciliated larva

2) Ciliated cells drop or reabsorb cilia, then grow flagella

Question 11

Ecology and Importance of sponges

Answer 11

• bioprospecting for pharmaceuticals
• make sponges
• reefs

Question 12

Two Phylums of Radiata

Answer 12

1) Phylum Cnidaria

2) Phylum Ctenophora

Question 13

Characteristics of Radiata

Answer 13

• True differentiated tissues
• Diploblastic
• Have organs
• Radial Symmetry

Question 14

Phylum Cnidaria

Answer 14

• Jellyfish, hrdras, corals
• Gastrodermis lines body cavity
• Epidermis on the outside

Question 15

Mesogloea

Answer 15

acellular matrix in between gastrodermis and epidermis

Question 16

Morphology of Cnidaria

Answer 16

• Mouth but no anus
• Tentacles for prey capture
• Enidocytes

Question 17

Two basic body forms of Cnidaria

Answer 17

1) Polyp: oral end upwards, aboral end attached to substrate

2) Oral end downwards and aboral up, free floating in water

Question 18

Cnidocytes

Answer 18

Unique cells

• Each cell contains very complex endocellular structure
• Used for defence and prey capture

Question 19

4 Classes of Cnidaria

Answer 19

1) Class Hydrozoa
2) Class Scyphozoa
3) Class Cubozoa
4) Class Anthozoa

Question 20

Class Hydrozoa

Answer 20

• Has most species
• Both polyp and medusa in life cycle
• Has life cycle very similar to alternation of generations

Question 21

Class Scyphozoa

Scyph =

Answer 21

• Spend most of life as medusa
• Scyph = cup
• Swim by contracting network of fibres around circumference of bell
  = Cup

Question 22

Class Cubozoa

Answer 22

• Look very similar to Scyphozoa
• Complex light and movement eyes along perimeter
• Extremely toxic cnidocytes

Question 23

Class Anthozoa

Answer 23

• Entirely polyps stage

- Corals

Question 24

Zooxanthellae

Answer 24

• Symbiotic algae

- Coral bleaching due to loss of

Question 25

Phylum Ctenophora

Answer 25

• All marine
• Move by beating thousands of cilia arranged in bands
• Lack hox genes

Question 26

Morphology of Ctenophora

Answer 26

• are largest organism to move entirely by ciliary action
• Two long tentacles used for prey capture
• Tentacles covered with colloblasts