BIO: Practice test ( + notes )

How do animals in phyla Platyhelminthes, nematoda, and annelida, differ from each other? Identify at least two primary ways. How are they similar?

( Look on notes )

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

1. Cephalization is the concentration of sense organs and nerve cells at the anterior end. 2. The first type of invertebrate to show cephalization was Flatworms ( Flatworms are in the Platyhelminthes Phylum )

What are three types of coeloms?

Acoelomate Pseudocoelomate True Coelomate

Identify an animal with each type of coelem

Acoelomate: Flatworms Pseudocoelomate: Roundworms True Coelomate: Earthworms

What is a hermaphrodite?

An orginism with both male and female parts. EX: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.

Describe 3 symmetry types and provide an example of each

Asymmetry: no symmetry EX:Sponge Bilateral: Dividing it into 2 identical sides EX: insects, worms, and people Radial: Body parts extending from a circle EX: Sea anemone, star fish.

Why are echinoderms evolutionarily closer to chordates than other invertebrates?

Because they are Deuterstomes

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

Choanocytes: sponges; these cells pull water into the sponge for feeding. Amoebocytes: sponges; carry food throughout the sponge. Cnidocytes: Jelly fish; stinging cells for which this phylum is known Chromatochores: Squid; these are pigment cells that allow squid and octopi to camoufla.

Cnidaria Examples

Crabs, horseshoe crabs, insects of all kinds, spiders, scorpions,ticks

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

Deuterostomes

Platyhelminthes Examples

Flat worms like planaria

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

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

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

It belongs to the Phylum Porifera(which means pore bearer), it is asymmetrical, it is the simplest of all multicellular organisms, organized at the cellular level ( no tissue )

Anthropoda Examples

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

Approximately what percent of animals are invertebrates?

More than 95%

Which phylum accounts for the most animals?

Phylum Arthropoda

Nematoda Examples

Round worms like heart worms

Echinodermata Examples

Sea starches, sea urchins, sand dollars

Mollusca Examples

Snail, oysters, squid, octopus, slugs, scallops

Porifera Examples

Sponges ( Pore-Bearing )

What is a coelom?

The coelom is the body cavity.

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.

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.

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.

Platyhelminthes

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

Nematopoda

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

Mollusca

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

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 means "Spiny Skin".

Porifera

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

Annelids Examples

segmented worm ( Earthworms, leech )