Sponges, Cnidarians, & Unsegmented Worms

Question 1

Structures of sponges

Answer 1

The inside layer of cells are called Collar Cells and are what create the current that moves water into the pores and out the Osculum. Contractile Cells around the pores control what enters. The Simple Skeleton is made of Sponging (protein fibres) and Spicules (Star-like shapes of silicone dioxide or calcium carbonate).

Question 2

Reproductive methods of Sponges

Answer 2

Sexual and Asexual

Question 3

Sexual Reproduction in sponges

Answer 3

Hermaphroditic (make both sperm and egg when Amoebocytes divide by Meiosis). When sperm and egg fuse they create a Zygote that develops into a Free-Swimming Larvae (for dispersal) released to form a new sponge.

Question 4

Asexual reproduction in sponges

Answer 4

Budding, Fragmentation and Regeneration, and Gemmules

Question 5

Gemmules

Answer 5

A Gemmule is a dormant mass of Amoebocytes surrounded by a protective layer of spicules. The adult sponge (fresh water) dies but the Gemmules survive and grow into the new sponges in the spring.

Question 6

Life cycle of cnidarians

Answer 6

egg/sperm-zygote-planula larvae-polyp-budding polyp-ephyra-medusa

Question 7

Functions of sponges

Answer 7

• Shelter/home for invertebrates
• Recycle nutrients in the ocean
• Food source for some snails, sea stars, and fish
• Recycled so we can use them to clean ourselves

Question 8

Structures of Cnidarians

Answer 8

Have tissue layers (Ectoderm and Endoderm). Have a sac like digestive system meaning same opening for food and waste. Have mesoglea in between the ectoderm and endoderm. Have a net like nervous system.

Question 9

Functions of Cnidarians

Answer 9

• Symbolic relationships with other animals (protection)
• Coral reefs create a large marine habitat that living organisms have become dependant upon for food and as a water break
• Nudibranch (sea slug) can eat cnidarian tissue and store the nematocysts to be used in defense against its own predators.

Question 10

Reproductive methods of the Cnidarian

Answer 10

sexual and asexual reproduction

Question 11

sexual reproduction of cnidarians

Answer 11

Hermaphroditic. Often requires both medusa and polyp forms. Most develop into free-swimming ciliated larva called planula for disposal.

Question 12

asexual reproduction in cnidarians

Answer 12

Budding.

Question 13

The three classes of Platyhelminthes

Answer 13

• Turbellaria- free living planarian
• Trematoda- parasitic flukes
• Cestoda- parasitic tapeworms

Question 14

Turbellaria- planarian structures

Answer 14

Soft flattened body covered in cilia. Mouth located in the middle of the body. Muscular Pharynx sucks food into the intestine. Flame cells filter out chemicals waste and water using beating cilia to pass through the body pores. Two anterior ganglia and a ladder of nerves.

Question 15

Turbellaria- planarians functions

Answer 15

Can rebuild their bodies after amputation

Question 16

Turbellaria- planarians reproduction

Answer 16

Sexual: Hermaphroditic but cannot fertilize their own eggs. After two individuals exchange speed, the resulting eggs (zygote) are laid in a protective cocoon and take 2-3 weeks to hatch

Asexual: Fragmentation and then Regeneration.

Question 17

Trematoda- flukes structures and functions

Answer 17

Tough outer covering, two oral suckers for anchoring to the host and feeding,

Question 18

Trematoda- flukes Reproduction

Answer 18

Hermaphroditic but some have separate sexes.

Question 19

Cestoda- tapeworms structures and functions

Answer 19

Have no mouth, digestive system, or sense organs. Have a nervous system, reproductive system, and excretory system. Solex, knob shaped head with hooks and suckers to attach to the host. Body segments called proglottids, each section contains a hermaphroditic reproductive system and are eventually shed.

Question 20

Cestoda- tapeworms reproduction

Answer 20

fertilized proglottid shed and turns into a young worm.

Question 21

Phylum Nematoda

Answer 21

Roundworms or Nematodes

Question 22

Nematoda- roundworms structures and functions

Answer 22

Complete one way digestive tract
tripoblasty: three tissue layers (Endoderm, mesoderm, ectoderm)
Pseudocoelom- partially lined body comity filled with fluid that acts as a hydrostatic skeleton
Cuticle that encompasses the organism of this phylum and as they grow it is shed off this is called moulting
have a mouth, pharynx, intestine, and anus
nerve ganglion with ventral and dorsal nerve cord

Question 23

Nematoda- roundworms reproduction

Answer 23

Only capable of sexual reproduction, either female or male, fertilized eggs (2n) can be developed inside or outside the body; some are hermaphroditic.

Question 24

Phylum Rotifera

Answer 24

Rotifers

Question 25

Rotifers structures and functions

Answer 25

Motile and transparent Complete digestive system Ciliated, pharynx, muscular jaw for grinding, stomach, intestine, and anus

Question 26

Rotifers reproduction

Answer 26

Sexual reproduction- both sexes females can do parthenogenesis- diploid female gives way to diploid eggs hatching diploid females that were not fertilized.