BIO EXAM 3 LEC 11

Question 1

What are the major characteristics of Porifera (sponges)?

Answer 1

Body has pores, canals, and chambers that form a system of water currents to helps the sponges get food and oxygen
2)Are all aquatic
3)Typically no symmetry
4)Interior is lined with choanocytes that create water currents
5) Its skeletal structure contains fibrillar collagen (spongin) and crystalline spicules (protection)
6) No organs or true tissues - excretion and respiration is done through diffusion
7) No nervous system, some electrical stimulation
8) Sessile and attached to substratum
9)Asexual reproduction through budding and sexual reproduction

Question 2

Crystalline Spicules

Answer 2

Pieces of silica or calcium that are used to defer predators and provides structural support

Question 3

Spongin

Answer 3

Fibrous structures that provides structure and support

Question 4

What is the phylum of radial animals?

Answer 4

Cnidaria

Question 5

Budding

Answer 5

How sponges reproduce asexually. Pieces of the sponge break off and settles down somewhere else and begins to undergo meiosis.

Question 6

What are the major characteristics of cnidaria?

Answer 6

1) Extensible tentacles that are used for feeding and protection
2)Nematocysts
3) Entirely aquatic
4)Radial Symmetry
5)2 body types -polyps and medusae
6) Extracellular digestion
7) Presence of a nerve net
8) Asexual and sexual reproduction
9)No excretory or respiratory system - diffusion accomplishes these processes.
10) Has tissue and is diploblastic

Question 6

Nematocysts

Answer 6

Stinging cells on the tentacles that has some types of venom that paralyzes its prey. Also give the species structure and protection

Question 7

polyps

Answer 7

Are sessile but still have tentacles and a mouth

Question 8

Medusae

Answer 8

Takes on the classic jellyfish shape and are motile

Question 9

Extracellular digestion

Answer 9

excrete digestive enzymes into the environment

Question 10

Nerve Net

Answer 10

It is a diffuse mesh of nerve cells that take part in simple reflex pathways. The nerve cells interact with sensory and contractile cells

Question 11

What are the four major classes of Cnidaria?

Answer 11

-Hydrozoa - Hydras
-Scyphozoa and Cubozoa - Jellyfish
-Anthozoa - Sea anemones, corals, and sea ferns

Question 12

Hydrozoa

Answer 12

Take on two life forms, the polyp phase and medusae phase. Are typically very small

Question 13

What is the life cycle of Hydrozoa

Answer 13

A
-First we see a polyp phase that had an obelia colony
-The Obelia colony has hydrotheca and Gonotheca which are buds on the colony
-The hydrotheca is responsible for food and protection
-The gonotheca is used for asexual reproduction and create medusae
-These medusae are hermaphrodite which produces both eggs and sperm
-When an egg and sperm cell come together they produce a zygote
-This forms into a Blastula which then turns into a free-swimming planula larva
-The larva settles down to start a new colony and the cycle repeats.

Question 14

Scyphozoa shape

Answer 14

Takes on the classic jellyfish medusae shape

Question 15

Cubozoa

Answer 15

Is more cube like in shape

Question 16

What falls under Anthozoa?

Answer 16

It includes the sea ferns, corals, and sea anemones

Question 17

What is the relationship between clown fish and sea anemones?

Answer 17

They have a mutualistic relationship. Sea anemones provide protection for clown fish against predators and the clown fish eat the parasites that live on the tentacles of the sea anemones.

Question 18

What are some characteristics of Sea Anemones?

Answer 18

They are relatively sessile and use water currents to fall side ways and drift away from predators.
-They have a mutualistic relationship with clown fish.

Question 19

What are some characteristics of Sea Ferns?

Answer 19

They are a-symmetrical

Question 20

What are some characteristics of corals?

Answer 20

They are the most diverse and productive tropical species
-Form an obligate mutualistic relationship with zooxanthellae

Question 21

Explain Coral Bleaching

Answer 21

Corals have an obligate mutalistic relationship with zooxanthellae. This algae are homed in healthy corals where they can photosynthesize and give the coral the energy and bright color they need to survive. When water temperatures get to high, the zooxanthellae is expelled from the coral’s tissue and the coral dies.

-Coral provides a home and nutrients and the zooxanthellae performs a number of metabolic processes for the corals.