Lab 5: Phylum Nematoda

Question 1

Within the clade bilateria, what are the two other clades that diverge from it?

Answer 1

Protostomia and Deuterostomia

Question 2

What clade within bilateria do platyhelminthes and nematoda belong to?

Answer 2

Protostomia

Question 3

What are the two clades within the protostomia clade?

Answer 3

Spiralia and Ecdysozoa

Question 4

From the clades diverged from the protostomia, what do platyhelminthes and nematoda come from?

Answer 4

Platyhelminthes belong to spiralia and nematoda belongs to Ecdysozoa

Question 5

Blastocoel

Answer 5

the fluid-filled space in the blastula

Question 6

What becomes the mouth in protostomes (nematodes)?

Answer 6

The blastopore

Question 7

What becomes the mouth and anus in deuterostomes?

Answer 7

a second opening becomes the mouth and the first opening, the blastopore, becomes the anus

Question 8

Are nematodes triploblastic?

Answer 8

Yes

Question 9

What kind of symmetry do nematodes have?

Answer 9

bilateral symmetry

Question 10

What is Spiralia?

Answer 10

refers to a special type of cleavage that occurs in early development in most animals clade; spiral cleavage

Question 11

What process is ecdysis?

Answer 11

the process of shedding the cuticle that covers the outside of a nematodes body

Question 12

What are acoelomates?

Answer 12

Animals without a body cavity. Ex. flatworm

Question 13

What is a blastocoelom?

Answer 13

The body cavity of nematodes; the space called the blastocoel develops into the blastocoelom in an adult roundworm.

Question 14

Does mesoderm fill the entire cavity in a nematode?

Answer 14

No, only along the inside of the body wall

Question 15

T/F The organs of the roundworm are not covered in tissue derived from mesoderm

Answer 15

True

Question 16

What kind of nervous system do nematodes have?

Answer 16

centralized

Question 17

What is the cuticles function in ecdysozoans?

Answer 17

-Maintaining shape, gives roundworms their shape
-Protection from a variety of environments including digestive enzymes parasitic roundworms would be exposed to
-Movement/locomotion: serves as an atagonist to longitudinal muscles

Question 18

What is the cuticle in ecdysozoans?

Answer 18

It covers the outside of the bodies, is multi-layered, composed primarily of collagen, and is secreted by the epidermis, and NON-LIVING

Question 19

T/F Nematodes have circular and longitudinal muscles

Answer 19

F: only longitudinal muscles that run the length of the worm

Question 20

What acts as the fluid-filled internal space of a hydrostatic skeleton in a nematode?

Answer 20

The blastocoelom

Question 21

What do roundworms feed on?

Answer 21

bacteria, fungus, small animals, and dead plants and animals (also many eat roots)

Question 22

What kind of digestive system does a nematode have?

Answer 22

Complete

Question 23

What does the digestive system of a nematode consist of?

Answer 23

a mouth, a muscular tube called pharnyx that pumps food into the intestine, and an anus

Question 24

What secretes enzymes in a nematode?

Answer 24

The intestine

Question 25

Where does the digested nutrients move from after the intestine?

Answer 25

The blastocoelom

Question 26

Cuticles are permeable to ___ and ___

Answer 26

gases and water

Question 27

What serves as a simple circulatory system and distributes gases and nutrients to all parts of the worm?

Answer 27

The fluid-filled blastocoelom

Question 28

What waste is excreted by nematodes?

Answer 28

Ammonia

Question 29

What germ layer does muscle tissue develop from?

Answer 29

Mesoderm