Bio 108 - Lecture 17 Flashcards Preview

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Flashcards in Bio 108 - Lecture 17 Deck (26):
1

Parazoa Characteristics
Para=
Zoo=

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

2

Two Phylums Parazoa belong too

1) Almost all belong to Phylum Porifera
2) Phylum Placozoa, only one species does

3

What Species Belongs to Phylum Placozoa

Trichoplax adharerens

4

Totipotent

cells can transform to do all jobs

5

Phylum Porifera Characteristics
Por=
Fer=

- 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

6

Two main types of cells in Phylum Porifera

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

7

Mesophyl in Porifera?
Meso=
Hyl=

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

8

Porifera Eating

Suspension feeding
Food particles are phagocytosed

9

Simultaneous Hermaphrodites vs Sequential

Simultaneous - are male and female at the same time
Sequential - are first one sex, then change to be the other

10

Behaviour of Zygote in Porifera

1) Zygote is retained until it develops into ciliated larva
2) Ciliated cells drop or reabsorb cilia, then grow flagella

11

Ecology and Importance of sponges

- bioprospecting for pharmaceuticals
- make sponges
- reefs

12

Two Phylums of Radiata

1) Phylum Cnidaria
2) Phylum Ctenophora

13

Characteristics of Radiata

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

14

Phylum Cnidaria

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

15

Mesogloea

acellular matrix in between gastrodermis and epidermis

16

Morphology of Cnidaria

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

17

Two basic body forms of Cnidaria

1) Polyp: oral end upwards, aboral end attached to substrate
2) Oral end downwards and aboral up, free floating in water

18

Cnidocytes

Unique cells
- Each cell contains very complex endocellular structure
- Used for defence and prey capture

19

4 Classes of Cnidaria

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

20

Class Hydrozoa

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

21

Class Scyphozoa
Scyph =

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

22

Class Cubozoa

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

23

Class Anthozoa

- Entirely polyps stage
- Corals

24

Zooxanthellae

- Symbiotic algae
- Coral bleaching due to loss of

25

Phylum Ctenophora

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

26

Morphology of Ctenophora

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