Bio 108 - Lecture 19 Flashcards Preview

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Flashcards in Bio 108 - Lecture 19 Deck (26):
1

Ecdysozoa

New group of protostomes
- Moult entire cuticle to grow

2

Ecdysis

Entire cuticle shed at once

3

Cuticle

- Non living outer layer of skin
- Frequently sclerotized in arthropods

4

3 Layers of Cuticle

1) Endocuticle
2) Exocuticle
3) epicutucle (epi = upon)

5

Moulting Process

1) Epidermis separates form the endocuticle
2) Inactive moulting fluid is secreted by epidermis
3) Thin protective layer is deposited between moulting fluid and epidermis
4) Endocuticle is digested
5) New undifferentiated layer of cuticle forms with greater surface area and wrinkled
7) New cuticle expanded
8) Outside of new cuticle is scloertized by secretions

6

Apolysis
apo =
lys =

When the epidermis separates from the endocuticle
= away
= loosening

7

Phylum Onychophora
Onych =
Phor =

- Velvet worms
- Soft body, segmented, and unjointed legs with tipped claws called Lobopods

8

Lobopods

Many pairs of unjointed legs tipped with claws

9

Onychophora Morphology

- Originally a mollusc, now Ecdysozoa
- Head is poorly developed, little cephalization
- Open circulatory system
- Haemolmyph directly bathes the organs
- Coelom becomes reduced to pockets around gonads during embryonic development
- Exchange gases using a tracheal system

10

Haemocoel

Open circulatory system

11

Tracheal system

- Openings in side of the body ( stigmata or spiracles)
- Lead to large-bore tubes (trachea)
- Terminate in many fine tubes (tracheoles)

12

Ecology of Onychophora

- All predators
- Capture prey from shooting glue from glands next to mouth
- Separate sexes (Dioecious)
- Several sperm transfer methods including hypodermic insemination
- Oviparous
- Ovoviviparous
- Viviparous

13

Hypodermic Insemination

- spermatophore places on females skin, digests trough into gaemocoel, sperm released and crawl to eggs

14

Oviparous
Ovi =
Pareo =

Lay eggs that undergo embryonic development outside females body
= egg
= to give birth

15

Ovoviviparous
Viv =

- Eggs retained in the mothers body where the young develop, nourished by yolk, and hatch inside the mother
= alive

16

Viviparous

- Young undergo development inside mother where they receive nutrients via a placental connection to mothers tissues

17

Phylum Tardigrada
Grad=
Tardi =

- Water bears
- Have 4 pairs of claw-tipped lobopod limbs
- Move by stepping
= stepping
= tardi

18

Phylum Nematoda
Nemato =

- Roundworms, threadworms
- Despite high species richness, morphologically tedious
- No eyes, segmentation, or appendages
- Pseudocoelomate
- Eutelic
- Caenorhabditis elegans is a model organism for studying development
- Medically important

19

Eutelic

Post-embryonic growth occurs by each cell growing, not addition of cells

20

Phylum Arthropoda

- Most species rich phylum
- Jointed limbs
- Sclerotized cuticle made of chitin
- Acts as endoskeleton
- Segmented bodies
- Well cephalized
- Other tagmata other then head

21

5 Main Groups of Arthropods

1) Trilobita
2) Cheliverata
3) Myriapoda
4) Crustacea
5) Hexapoda

22

Trilobita

- Trilobites ,all extinct

23

Chelicerata

- Scorpions, spiders, mites

24

Myriapoda

- Millipedes, Centipedes

25

Crustacea

- Crabs, lobsters

26

Hexapoda

Insects, springtails