Chapter 27: Intriduction to Animal Diversity

What are the six major features of the animal kingdom?

• Multicellular eukaryotes

• Heterotrophic (Ingestive)

• Active movement (muscle + nervous tissue)

• Sexual reproduction (some asexual)

• Embryonic development (blastula → gastrula)

• Body plan (symmetry, tissues, cavities)

What protein is unique to animals and found in the extracellular matrix?

Collagen

What two cell types are unique to animals

Muscle cells and Nerve cells

What type of heterotrophs do most animals use?

Ingestive heterotrophy

What type of life cycle do animals have?

Diploid dominant life cycle (only gametes are haploid)

What are the main types of asexual reproduction in animals?

Fragmentation, regeneration, budding, parthenogenesis

What is metamorphosis?

Transformation from larval form to adult form

What is the difference between complete and incomplete metamorphosis?

• Complete: larva → pupa → adult (different forms)

• Incomplete: juvenile resembles adult; gradual change

What is the order of early embryonic development?

Zygote→Cleavage→Blastula→Gastrula

What is gastrulation?

Formation of germ layers and the archenteron

What are the three germ layers

Ectoderm, Mesoderm, Endoderm

Diploblastic animals have which germ layers?

Ectoderm + Endoderm

Triploblastic animals have which germ layers?

Ectoderm, Mesoderm, Endoderm

What type of cleavage do protostomes have?

Spiral and determinate

What type of cleavage do Deuterostomes have?

Radial and indeterminate

In protostomes what does the Blastopore become

The mouth

How is the coelom formed in protostomes

Solid masses of mesoderm split and form coelom

How is the coelom formed in Deuterostomes

Folds of archenteron form coelom

In Deuterostomes what does the Blastopore become

The anus

What are the three types of symmetry in animals

Asymmetry, radial symmetry, bilateral symmetry

What is cephalization

Concentration of sensory organs at the anterior end

What is a coelom

A fluid filled body cavity between the digestive tract and body wall

What are the three types of body cavities

Acoelomate, Pseudocoelomate, Coelomate

What is the function of a coelom?

Cushion organs and allows independent movement of internal organs

What do Hox genes control?

Body plan, segmentation, and placement of appendages

Why are Hox genes important evolutionarily

They are highly conserved and regulate development across animals

What group is the closest living relative to animals

Choanoflagellates

What is the Ediacaran biota?

• The earliest known animal fossils

• Soft bodied organisms

Paleozoic Era

Vertebrae fishes and reptile like amniotes

What was the Cambrian Explosion

Rapid diversification of animal phyla

Which era saw the rise of dinosaurs

Mesozoic Era

Which era saw diversification of modern animal groups

Cenozoic Era

What are the three major clades of Bilateria

• Deuterostomia

• Lophotrochozoa

• Ecdysozoa

Which phylum is the sister group to all other animals

Porifera (sponges)

What defines Eumetazoa

Animals with true tissues

What defines Bilateria

Bilateral symmetry + Triploblastic development

What are cells in animals joined by

Extracellular matrix (ECM)

What does it mean to be hermaphroditic

Male and Female in 1 individual

What is parthenogenesis

Virgin females produce eggs that develop into offspring

What is the ectoderm

Gives rise to outer covering and nerves

What is the endoderm

Digestive tract; internal organs, lungs

What is the mesoderm

Between ectoderm and endoderm that protects muscles, bone, blood, etc