Tutorial 3

Question 1

phylum cnidaria

Answer 1

diplobastic organsims

Question 2

symmetry in phylum cnidaria

Answer 2

they have radial symmetry

Question 3

2 layers in cnidaria

Answer 3

epidermis and the inner gastrodermis

Question 4

2 body forms of the cnidaria

Answer 4

polyp and medusa

Question 5

what are cnidocytes

Answer 5

they are specialized cells

cnidocyctes -> nematocysts -> that are used to immoblize the prey

Question 6

what is the characteristic feature in the phylum cnidaria

Answer 6

they have a body cavity called as the gastrovascular cavity

Question 7

what is the name of the layer that is found in between the epidermis and the gastrodermis

Answer 7

mesoglea

Question 8

mesoglea

Answer 8

it is the non cellular layer in between the epidermis and the gastrodermis

Question 9

ingestion and digestion in the phylum cnidaria

Answer 9

the prey is immoblized by the tentcales -> ingested -> degraded in the gastrovascular cavity -> the small particles would be ingulfed by the gastrodermial cells by PHAGOCYTOSIS

Question 10

Polyp reproductive generation

Answer 10

asexual

Question 11

Medusa reproductive generation

Answer 11

sexual

Question 12

obelia

Answer 12

1. medusa body form
2. they live in colonies

Question 13

hydrothecae

Answer 13

feeding nutritive polyps that posses tencales

Question 14

Gonothecae

Answer 14

club shaped, lack tentacles and are the reproductive polyps

Question 15

perisarc

Answer 15

the branches of the colonies of the obelia are covered with a transparent sheath known as perisarc

Question 16

manubrium

Answer 16

cavity found in medusa, which contains a mouth at its one tip and surrounded by 4 oral lobes

Question 17

phylum Platyhelminthes

Answer 17

flatworm like animals
example - planarian

Question 18

symmetry in phylum Platyhelminthes

Answer 18

bilaterally symmetrical

Question 19

cellular layers in flatworms

Answer 19

the phylum Platyhelminthes are all triploblastic

Question 20

body cavities in flatworms

Answer 20

The phylum Platyhelminthes lack a body cavity hence are acoelomate but otherwise are very well developed.

Question 21

the three germ layers in Platyhelminthes

Answer 21

gastrodermis < parenchyma tissues < epidermis

Question 22

feeding and digestion in planarian

Answer 22

they are mainly carnivorous

they have a blind digestive tract i.e. only one opening

Question 23

osmoregulation and excretion in planarian

Answer 23

the excess water and waste enters the flame cells system and is then propelled through the tubules by beating of the cilia