Animal Diversity Notes

What is Ecdysozoa?

A group of animals that have an exoskeleton and grow by molting (shedding their outer layer), such as insects and other arthropods.

What are animals?

Multicellular, heterotrophic eukaryotes

How do animals get food?

By ingestion

What makes animal cells unique?

No cell walls, have collagen

What is a zygote?

Fertilized egg

What is cleavage?

Rapid cell division

What is a blastula?

Hollow ball of cells

What is gastrulation?

Formation of germ layers

What are the 3 germ layers?

Ectoderm, mesoderm, endoderm

What is diploblastic?

Two layers

What is triploblastic?

Three layers

What is a larva?

Immature stage different from adult

What is metamorphosis?

Change from larva to adult

What do Hox genes do?

Control body development

When did animals evolve?

~770 million years ago

What was the Cambrian explosion?

Rapid diversification of animals

What is radial symmetry?

radial symmetry

What is bilateral symmetry?

bilateral symmetry

What is a coelom?

Fluid-filled body cavity

Why is a coelom important?

Protects organs and aids movement

In protostomes, what does the blastopore become?

Mouth

In deuterostomes, what does the blastopore become?

Anus

What type of cleavage do protostomes have?

Spiral, determinate

What type do deuterostomes have?

Radial, indeterminate

What are bilaterians?

Animals with bilateral symmetry

What are eumetazoans?

Animals with true tissues

What animals are deuterostomes?

Starfish and humans

What is Ecdysozoa known for?

Molting (shedding exoskeleton)

What is a lophophore?

Feeding structure

What is the main trend in animal evolution?

Increasing complexity