Biology chapter 25 and 26

What are the 3 types of coeloms?

Acoelomate - No body cavity Pseudocoelomate - false body cavity—organs lined with fluid Coelomate - true body cavity—organs lined with mesoderm

Identify an animal with each type of coelem.

Acoelomate - flatworm Pseudocoelomate - roundworm Coelomate - earthworm

What other two features are present in animals with three embryonic germ layers?

Animals with three embryonic germ layers are bilateral and have cephalization

Segmented worm (earthworm, leech)

Annelida

The name of this phylum means "little rings", which identifies the ringed segments that make up their bodies. These animals have cephalization and bilateral symmetry. They are hermaphrodites.

Annelida

Crabs, horseshoe crabs, insects, spiders, scorpions, ticks

Arthropoda

The name of this phylum means "jointed foot", so all of the animals in this phylum have jointed legs and segmented bodies. They have bilateral symmetry and cephalization.

Arthropoda

Describe the 3 symmetry types and provide an example of each?

Asymmetry—no symmetry Ex. Sponges Radial- body parts extend from a circle EX. sea anemone, starfish Bilateral -divide into 2 identical side, mirror image EX. people, insects, worms

What is unique about the sponge compared to other animal groups:

Belong to Phylum Porifera - means pore bearer Asymmetrical -no symmetry Simplest of all multicellular organisms, organized at the cellular level (no tissues)

What is cephalization and what is the first type of invertebrate to show cephalization

Cephalization is the concentration of sense organs and nerve cells at the anterior end. The first type of invertebrate to show cephalization is the flatworm (Platyhelminthes)

Identify in which animals you can find these types of cells, and what they do for the animal: choanocytes (collar cells), amoebocytes, cnidocytes, chromatochores.

Choanocytes (Collar cells) - sponges; these cells pull water into the sponge for feeding Amoebocytes - sponges; these cells carry food throughout the sponge. Cnidocytes - jelly fish; these cells are stinging cells for which this phylum is known. Chromatochores - squid; these are pigment cells that allow squid and octopi to camouflage.

Jellyfish, Portuguese man of war, box jellies, anemones, coral

Cnidaria

These animals all are equipped with stinging cells used for defense and to catch prey. They exhibit radial symmetry but are formed from only ectoderm and endoderm embryonic germ layers.

Cnidaria

Which of the two from #9 represents the more complex organisms like humans?

Deuterostomes

Sea stars, sea urchins, sand dollars

Echinodermata

These animals have radial symmetry. That means they have no cephalization, however, they are deuterostomes which makes them more related to chordates than other invertebrates. Their name literally means "spiny skin".

Echinodermata

Why are echinoderms evolutionary closer to chordates than other invertebrates?

Echinoderms are evolutionarily closer to chordates than other invertebrates because they are deuterostomes.

What is the difference between protostome embryonic development and deuterostome embryonic development?

In a protostome the mouth develops first while in the deuterostome the anus develops first and the mouth develops from the second opening.

Snails, oysters, squid, octopus, slugs, scallops

Mollusca

These animals have either an external or internal shell. Some have one shell while others have two. The most "intelligent" of this phyla have an internal shell. They have a larval stage called a trochophore.

Mollusca

Approximately what percent of animals are invertebrates?

More than 95%

Round worms like heartworms

Nematoda

These animals are pseudocoelomates. Most are parasitic. They do have cephalization and bilateral symmetry.

Nematoda

Which phylum accounts for the most animals?

Phylum Arthropoda

Flat worms like planaria

Platyhelminthes

These animals are acoelomate but they do have bilateral symmetry and cephalization.

Platyhelminthes

Sponges

Porifera

These animals only have cellular level of organization. They live a sessile existence and are filter feeders. Their name means "pore bearer". They have no symmetry.

Porifera

What is a coelom?

The coelom is the body cavity that develops within the mesoderm and is completely lined with tissue from the mesoderm.

How do animals in phyla Platyhelminthes, Nematoda, and Annelida, differ from each other (identify at least two primary ways)? How are they similar?

Type: 1. Platyhelminthes 2. Nematoda 3. Annelida (flatworms) (round worms) (earthworms) Same 1. Bilateral 3 germ layers Cephalization 2. Bilateral 3 germ layers Cephalization 3. Bilateral 3 germ layers cephalization Different 1. Acoelomate Not segmented 2. Pseudocoelomate Not segmented 3. Coelomate segmented

What is a hermaphrodite?

animal that has both male and female reproductive parts