Unit 3: Chp 3 - Animalia

Kingdoms: Animalia

What are *animals?*

* most complex organisms
* multi-cellular eukaryotes

Why are *animals important?*

* help us understand humans better
* provide resources and comfort (pets)

What is believed to be the *common ancestor* *for all animals?*

* lived approximately 800 million years ago
* small, flagellated, unicellular organism

What is *bilateral symmetry?*

It’s the symmetry of animals that splits body parts along the midline with mirror images on either side (usually left and right)

What is *radial symmetry?*

It’s the symmetry of animals that splits body parts **around a central point** with **multiple planes** of symmetry

How can animals be *classified*?

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* **embryonic development:** protostome (mouth first then anus - vertebrate rankings) and deuterostomes (anus then mouth - aquatic creatures)
* **spinal column:** vertebrate (has one) and invertebrate (doesn’t have one)
* **symmetry**: bilateral (left and right) and radial (around central point/axis)

What is a *protosome*?

An organism that develops a **mouth first** then the **anus**; every other animal - tiger, dog, rat

What is a *deuterosome?*

An organism that develops an **anus first** then the **mouth**; aquatic creatures - starfish, urchin

What is a *vertebrate*?

It’s an animal *with* a vertebral column/spine

What is an *invertebrate?*

It’s an animal *without* a vertebral column/spine

What are *germ layers?*

They’re layers of cells that become specialized tissues: *ectoderm (outer), mesoderm (middle), and endoderm (inner)*

What does the *ectoderm layer* do?

* outer-layer
* gives rise to the skin and nervous system
* some can produce shells, scales, feathers, or hair

What does the *endoderm layer* do?

* inner-layer
* forms lining of the gut
* for some organisms, their respiratory system

What does the *mesoderm layer* do?

* middle-layer
* gives rise to the circulatory, reproductive, excretory, and muscular systems

What is a *coelom?*

It’s a fluid filled body cavity that:

* separates the gut from the body wall
* provides space for internal organ growth
* grown from the *mesoderm layer*

What are the *simplest invertebrates?*

Porifera and cnidaria

What are the key characteristics of *porifera?*

* look like coral
* immobile and range in size
* hermaphrodites (organisms with both male and female parts) pass through pores in the body wall

What are the key characteristics of *cnidaria?*

* look like jellyfish
* no mesoderm
* specialized nerve, muscle, digestive, and reproductive tissue
* skeletons made of calcium chloride

What are the *6 phyla of invertebrates*?

Arthropoda, nematoda, annelida, mollusca, rotifera, platyhelminthes 

What are the key characteristics of *arthropoda?*

* creatures with grabby arms - crab, scorpion, spider
* segmented bodies with joint appendages
* complex sensory system
* vital in both aquatic and terrestrial ecosystems

What are the key characteristics of *nematoda?*

* parasitic worms
* unsegmented, completely digestive, bodies
* parasites

What are the key characteristics of *annelida?*

* regular worms - earthworm
* mostly segmented bodies and organs
* gas exchange through skin/gill
* bristles on the outer bodies for movement
* mostly aquatic

What are the key characteristics of *protosome* *mollusa?*

* snails
* three unsegmented sections: foot, mass (body), and mantle
* special radula (tongue) for scraping

What are the key characteristics of *protosome* *rotifera?*

* tiny aquatic ‘animals’ (smaller thna 2mm)
* live in fresh water
* no respiratory or circulatory system

What are the key characteristics of *platy-helminthes?*

* flat, tiny (1-5mm), unsegmented on worms
* digestive cavity with only one opening
* no coelom

What are the two *subgroups* off the *Deuterostomes?*

Echinoderms and chordates

What are the key characteristics of *echinoderms?*

* subgroup of deuterosomes
* no head (eyeless animals - starfish, urchin)
* no respiratory, circulatory, or excretoy system

What are the key characteristics of *chordates?*

* subgroup of deuterosomes
* includes almost every animal
* success from the **development of**: notochord (enhance mobility), limbs, waterproof amniotic egg, large internal skeleton and vertebrate skeleton

What are the *7 major phyla of vertebrates*?

* **Agnathans** (jawless fishes - eels, lamprey)


* **Chondrichthyes** (cartilaginous fishes - predators: sharks, rays)
* **Actinopterygii** (bony fish - salmon, bass, tuna)
* **Amphibia** (cold-blooded - frog, salamander)
* **Reptilia** (cold - lizard, snake, turtle)
* **Aves** (birds - warm-blooded), M
* **Mammalia** (warm, humans, whales, bats)