BIOL 2 Invertebrates

What is the current debate?

What are the early branching order of animals (Metazoa)

Why are porifera considered the most basic animals?

No tissues, no organ systems, no hox genes (control body plan)

What did the evolution of hox genes do?

New and complex body plans

What also lack hox genes?

Ctenophores

What are sponges?

Porifera

What had complex multicellularity, were filter feeders, and and sexual & asexual reproduction (hermaphrodites)?

Porifera (sponges)

develop two embryonic germ layers: an ectoderm and an endoderm or mesendoderm

Diploblasts

develop a third layer—the mesoderm—which arises from mesendoderm and resides between the endoderm and ectoderm.

Triploblasts

the outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis and nerve tissue.

ectoderm

the innermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the lining of the gut and associated structures.

endoderm

a transient, bipotential layer of cells in early embryonic development that differentiates into both the mesoderm and endoderm, the two germ layers that give rise to various tissues and organs. (arises from mesendoderm)

mesendoderm

the middle developmental layer between the ectoderm and endoderm, which gives rise to the skeleton, muscle, heart and bones.

mesendoderm

Cnidaria is:

Diploblast

Endoderm

Inner Derm (skin) Layer

Mesoderm

Middle Derm (skin) Layer

Ectoderm

Outer Derm (skin) Layer

What are the three layers here?

Diploblast

Yellow: Endoderm

Green: Non-living tissue

Blue: Ectoderm

What are the three layers here?

Mesoderm

Yellow: Endoderm

Orange: Mesoderm

Blue: Ectoderm

Do porifera have symmetry?

No

Does Cnidaria have radial symmetry?

Yes

All diploblastic animals have radial symmetry

True

What type of symmetry?

No symmetry

What type of symmetry?

Radial

What type of symmetry?

Bilaterial

the process involving the concentration of sensory and feeding organs such as nerve cells, mouth, and jaws at the anterior end and the development of the brain.

Cephalization

All of what animals are triploblastic?

Bilaterally symmetry animals

Most of what animals have a clear head (cephalization)?

Bilaterians

What are jellyfish, corals, sea anemones, and hydra?

Cnidaria

What have specialized stinging cells (nematocysts) for feeding?

Jellyfish, corals, sea anemones, hydra (Cnidaria)

Corals form symbioses with

dinoflagellates (Symbiodinium)

Calcium carbonate skeleton in 'reef building' coral critical to

marine ecosystems

What is "first mouth"?

Protostoma

What is 'second mouth'?

Deuterostoma

What are the two groups of protostomes?

LOPHOTROCHOZOA & ECDYSOZOA

This group had organisms with lorphophore or trochophore larvae

LOPHOTROCHOZOA

This group had organisms that would shed their exoskeleton

Ecdysozoa

"shedding"

Ecdysis

What group are flatworms, tape worms, and flukes a part of?

Platyhelminthes

What are able to reproduce by fragmentation?

Triploblast, Aceolomate

Some flatworms and flukes are human parasites and a global health concern; particularly in areas without _____________________________

adequate food and water sanitation

"not" is also known as

A

body cavity, fluid filled space with organs

Coelom

contained completely within the mesoderm

True Coelom

"false" is also known as

Pseudo

What does the distribution of coelom types across molecular phylogeny suggest?

Coelom is not homologous (i.e. evolved in multiple lineages)

What are the only acoelomates?

Platyhelminthes

______________________ are the only bilateral, triploplastic organism that does not have a body cavity

Platyhelminthes

Which are the only pseudocoelomates?

Rotifers & Nematodes

What are across Protostomes/Deuterostomes?

Platyhelminthes and Rotifers & Nematodes

What group are Octopus, Cuttlefish, Clams, Snails, Slugs, Squid in?

Mollusca

"soft body"

Mollusca

What are the earliest coelomates?

Mollusca

What group has many organisms excrete calcareous shell to protect soft body?

Mollusca

What group has the 2nd most species of any animal phylum?

Mollusca

Which group has about 100K species living and about 80K species extinct?

Mollusca

What group has Earthworms, leeches, many marine forms?

Annedlia

"ringed"

Annelida

Which group has organisms with the earliest segmented body plan?

Annelida

Segmentation is found in which three phyla?

Annelids, Arthropods, and Chordates

Most evidence points towards __________________________________ evolution of the segmented body plan and the segmentation process in these three phyla.

independent (convergent)

What is the first advantage of segementation?

Robust development of repeating units of different organ systems along the body axis.

What is the second advantage of segmentation?

Improved locomotion

What is the third advantage of segmentation?

Developmental modularity - can modify sub parts of the body without affecting others

What group is Nemerteans a part of?

Lophotrochozoa

Ribbon words are

Nemerteans

What are similar to flatworms and can reproduce by fragmentation, has separate males and females, and eversible (turn inside out) proboscis for feeding)

ribbon worms (Nemerteans)

Rotifers are a part of?

Lophotrochozoa

What are the oldest asexual animals?

Rotifers

Pseudocoelomate are a part of?

Rotifers (Lophotrochozoa)

Pseudocoelomate and Bedelloids rotifers are a part of?

Rotifers (Lophotrochozoa)

Round worms are also known as

Nematoda

What group are Nematoda a part of?

Ecdysozoa

What is a pseudocoelomate?

Round worm (dematoda)

What causes trichinosis mainly from undercooked meat?

Trichinella

What are many mammal parasites a part of?

Nematoda (round worms)

'joint footed'

Arthropoda

Which phylum is the most diverse animal phyla?

Arthropoda (Ecdysozoa)

What are the four major groups of Arthropoda?

Crustaceans, Arachnids, Myriapoda, Hexapoda

What is present in all Arthrpods?

exoskeletons

What does exoskeletons provide?

protection, mechanical support, prevents desiccation

Do exoskeletons grow with the animal?

No

What must be molted (shed) for animals to grow?

Exoskeleton

What is the similarity between Arthropods and Fungi?

both have chitin (fungi have a cell wall made of chitin)

a strong, flexible, and naturally occurring polymer that makes up the exoskeletons of arthropods

chitin

Complete metamorphosis

Holometabolous (egg, larva, pupa, adult)

Incomplete metamorphosis

Hemimetabolous (egg, nymph, adult)

What comprise of approximately 22% of ALL known living species (not just animals)?

Coleoptera (beetles)

Tardigrades (water bears) are a part of what grpup?

Ecdysozoa

'spiny skin'

Echinoderms

What are echinoderms a part of?

Deuterostoma

Sea stars, sea cucumbers, sea urchins, and sand dollars a part of?

echinoderms (deuterostoma)

What has re-evolved radial symmetry (many larvae are bilaterial, but become radially symmetric adults)

echinoderms

What defines the Chordata?

nerve cord, tunicates, lancelets, vertebrates

What are the major evolutionary transitions?

• Multicellular/specialized cells

• Tissues

• Radial symmetry

• Bilateral/Triploplastic

• Body cavity

• Protostome vs. Deuterostome